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  Subjects -> CHEMISTRY (Total: 842 journals)
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    - INORGANIC CHEMISTRY (41 journals)
    - ORGANIC CHEMISTRY (44 journals)
    - PHYSICAL CHEMISTRY (67 journals)

INORGANIC CHEMISTRY (41 journals)

Showing 1 - 41 of 41 Journals sorted alphabetically
Acta Polymerica     Hybrid Journal   (Followers: 9)
Additives for Polymers     Full-text available via subscription   (Followers: 20)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 9)
Advances in Polymer Technology     Hybrid Journal   (Followers: 13)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 3)
Bioinorganic Chemistry and Applications     Open Access   (Followers: 9)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Current Methods in Inorganic Chemistry     Full-text available via subscription   (Followers: 2)
European Journal of Inorganic Chemistry     Hybrid Journal   (Followers: 11)
European Polymer Journal     Hybrid Journal   (Followers: 41)
Heterocyclic Communications     Hybrid Journal  
High Performance Polymers     Hybrid Journal   (Followers: 1)
Indian Journal of Chemistry - Section A     Open Access   (Followers: 7)
Inorganic Chemistry     Full-text available via subscription   (Followers: 25)
Inorganic Chemistry Communications     Hybrid Journal   (Followers: 12)
Inorganic Chemistry Frontiers     Full-text available via subscription   (Followers: 3)
Inorganic Materials     Hybrid Journal   (Followers: 4)
Inorganic Materials: Applied Research     Hybrid Journal   (Followers: 1)
Inorganica Chimica Acta     Hybrid Journal   (Followers: 9)
Inorganics     Open Access  
International Journal of Bio-Inorganic Hybrid Nanomaterials     Open Access   (Followers: 1)
JBIC Journal of Biological Inorganic Chemistry     Hybrid Journal   (Followers: 4)
Journal of Inorganic and Organometallic Polymers and Materials     Partially Free   (Followers: 9)
Journal of Inorganic Biochemistry     Hybrid Journal   (Followers: 6)
Journal of Polymer Engineering     Hybrid Journal   (Followers: 9)
Journal of Polymers and the Environment     Hybrid Journal   (Followers: 1)
Journal of Separation Science     Hybrid Journal   (Followers: 9)
Materials Today Chemistry     Hybrid Journal  
Metallodrugs     Open Access   (Followers: 1)
Open Journal of Inorganic Chemistry     Open Access   (Followers: 3)
Plasmas and Polymers     Hybrid Journal  
Polymer Bulletin     Hybrid Journal   (Followers: 7)
Polymer Composites     Hybrid Journal   (Followers: 15)
Polyoxometalate Chemistry     Open Access  
Reviews in Inorganic Chemistry     Hybrid Journal  
Russian Journal of Inorganic Chemistry     Hybrid Journal  
Studies in Inorganic Chemistry     Full-text available via subscription  
Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry     Hybrid Journal   (Followers: 1)
Topics in Inorganic and General Chemistry     Full-text available via subscription  
Zeitschrift für anorganische und allgemeine Chemie     Hybrid Journal   (Followers: 2)
Zeitschrift für Kristallographie - New Crystal Structures     Open Access  
Journal Cover Journal of Inorganic Biochemistry
  [SJR: 0.983]   [H-I: 100]   [6 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0162-0134
   Published by Elsevier Homepage  [3043 journals]
  • para-Sulfonatocalix[4]arene and polyamidoamine dendrimer nanocomplexes as
           delivery vehicles for a novel platinum anticancer agent
    • Authors: Chi Ting Pang; Alaina J. Ammit; Yu Qing Elysia Ong; Nial J. Wheate
      Pages: 1 - 7
      Abstract: Publication date: November 2017
      Source:Journal of Inorganic Biochemistry, Volume 176
      Author(s): Chi Ting Pang, Alaina J. Ammit, Yu Qing Elysia Ong, Nial J. Wheate
      Novel para-sulfonatocalix[4]arene (sCX[4]) and polyamidoamine (PAMAM) dendrimer nanocomplexes were evaluated as delivery vehicles for the platinum anticancer agent [(1,10-phenanthroline)(1S,2S-diaminocyclohexane)platinum(II)] chloride (PHENSS). Different ratios of sCX[4] to PHENSS were tested for their compatibility, with a ratio of 6:1 sCX[4]:PHENSS having the best solubility. The loading of sCX[4], and sCX[4]-bound PHENSS, onto three different generations of PAMAM dendrimers (G3.0–5.0) was examined using UV–visible spectrophotometry. The quantity of sCX[4] bound was found to increase exponentially with dendrimer size: G3, 15 sCX[4] molecules per dendrimer; G4, 37; and G5, 78. Similarly, the loading of sCX[4]-bound PHENSS also increased with increasing dendrimer size: G3, 7 PHENSS molecules per dendrimer; G4, 14; and G5, 28.5. The loading of sCX[4]-bound PHENSS molecules is significantly lower when compared with that of sCX[4], which indicates that less than half of the binding sites were occupied (45, 44, and 44%, respectively). By 1H NMR and UV–vis analysis, the nanocomplex was found to be stable in NaCl solutions at concentrations up to 150mM. While PHENSS is more active in vitro than cisplatin against the human breast cancer cell line, MCF-7, delivery of PHENSS using the sCX[4]-dendrimer nanocomplexes, regardless of dendrimer generation, had little effect on PHENSS cytotoxicity. The results of this study may have application in the delivery of a variety of small molecule metal-based drugs for which chemical conjugation to a nanoparticle is undesired or not feasible.
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      PubDate: 2017-08-16T19:14:15Z
      DOI: 10.1016/j.jinorgbio.2017.08.002
      Issue No: Vol. 176 (2017)
       
  • Anti-cancer gold(I) phosphine complexes: Cyclic trimers and tetramers
           containing the P-Au-P moiety
    • Authors: T. Srinivasa Reddy; Steven H. Privér; Nedaossadat Mirzadeh; Suresh K. Bhargava
      Pages: 1 - 8
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): T. Srinivasa Reddy, Steven H. Privér, Nedaossadat Mirzadeh, Suresh K. Bhargava
      We report the application of cationic tri- and tetra-nuclear gold(I) phosphine complexes [Au3(μ-dppen)3]X3 and [Au4(μ-dppa)4]X4 (X=OTf, PF6) [OTf=trifluoromethanesulfonate, dppen= trans-1,2-bis(diphenylphosphino)ethene, dppa=bis(diphenylphosphino)acetylene] for cancer treatment. The results of cytotoxicity tests on four different cancer cells [prostate (DU145), cervical (HeLa), breast (MDAMB-231) and fibro sarcoma (HT1080)] indicate these complexes possess remarkable tumor cell growth inhibitory effects and high selectivity towards cancer cells. The anti-tumor mechanism of the tri- and tetra-nuclear gold(I) complexes has also been investigated.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.06.010
      Issue No: Vol. 175 (2017)
       
  • Roles of a mitochondrial AccSCO2 gene from Apis cerana cerana in oxidative
           stress responses
    • Authors: Haihong Jia; Manli Ma; Na Zhai; Zhenguo Liu; Hongfang Wang; Xingqi Guo; Baohua Xu
      Pages: 9 - 19
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Haihong Jia, Manli Ma, Na Zhai, Zhenguo Liu, Hongfang Wang, Xingqi Guo, Baohua Xu
      In eukaryotes, cytochrome c oxidase (COX) is a multimeric protein complex that is the last enzyme in the respiratory electron transport chain of mitochondria. Syntheses of cytochrome c oxidase (SCO) proteins are copper-donor chaperones involved in metalation of the CuA redox center of COX. However, its other precise actions are not yet understood. Here, we report the characterization of AccSCO2 from Apis cerana cerana (Acc). Our data showed that AccSCO2 expression was induced by cold (4°C), CdCl2, HgCl2, ultraviolet (UV) light, and H2O2 and was inhibited by different pesticide treatments. In addition, a disc diffusion assay of recombinant AccSCO2, AccSCO2-R1, and AccSCO2-R2 proteins showed that they played a functional role in protecting cells from oxidative stress involved in copper-dependent manner. Further, following knockdown of AccSCO2 in A. cerana cerana using RNA interference (RNAi), the expression levels of most antioxidant genes (AccGSTD, AccGSTO1, AccGSTS4, AccSOD1, AccSOD2, etc.) were significantly decreased in the AccSCO2-silenced bees compared with the control bees. Moreover, the antioxidant enzymatic activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were all lower in the silenced bees than in the control bees. Finally, the in vivo activity of COX was measured after AccSCO2 knockdown, which revealed a strong reduction in COX activity in the silenced bees. Thus, we hypothesize that AccSCO2 plays important roles in cellular stress responses and anti-oxidative processes, which help to regulate the production of mitochondrial reactive oxygen species and/or the impairment of mitochondrial activity under oxidative stress.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.06.015
      Issue No: Vol. 175 (2017)
       
  • Improve the anticancer potency of the platinum(II) complexes through
           functionalized leaving group
    • Authors: Jian Zhao; Dan Wang; Gang Xu; Shaohua Gou
      Pages: 20 - 28
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Jian Zhao, Dan Wang, Gang Xu, Shaohua Gou
      Two platinum(II) complexes with 3,3-dimethoxycyclobutane-1,1-dicarboxylate as a leaving group were synthesized and spectrally characterized. In vitro cytotoxicity study on these complexes indicated that complex 2 showed considerable cytotoxicity against the tested cell lines. Notably, the higher antiproliferative activity of complex 2 relative to the corresponding parent compound [Pt(dach)(CBDCA)] demonstrated that the introduction of two methoxy groups in the 1,1-cyclobutanedicarboxylate (CBDCA) can improve the anticancer activity of the resulting platinum(II) complexes. Moreover, cellular accumulations of complexes 1 and 2 were slightly higher than those of their parent compounds carboplatin and Pt(dach)(CBDCA), respectively. Flow cytometry study revealed that complexes 1 and 2 produced death of tumor cells through an apoptotic pathway. Comparison of the chemical reactivity of Pt(dach)(CBDCA) and complex 2 with biologically relevant nucleophiles (l-Met and thiourea) via a kinetic method were studied by UV–Vis technique. The results showed that the reaction rates of complex 2 with nucleophiles were faster than that of Pt(dach)(CBDCA). DFT calculations showed that Pt(dach)(CBDCA) has slightly higher activation energies than complex 2 for the studied reactions. Overall, the introduction of two methoxy groups to the skeleton of 1,1-cyclobutanedicarboxylate can not only change the kinetic reactivity of the resulting platinum(II) complexes, but also enhance their anticancer efficacy.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.06.016
      Issue No: Vol. 175 (2017)
       
  • Synthesis and characterization of oxidovanadium complexes as enzyme
           inhibitors targeting dipeptidyl peptidase IV
    • Authors: Ming-jin Xie; Ming-rong Zhu; Chun-Mei Lu; Yi Jin; Li-Hui Gao; Ling Li; Jie Zhou; Fan-fang Li; Qi Hua Zhao; Hong-Ke Liu; Peter J. Sadler; Carlos Sanchez-Cano
      Pages: 29 - 35
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Ming-jin Xie, Ming-rong Zhu, Chun-Mei Lu, Yi Jin, Li-Hui Gao, Ling Li, Jie Zhou, Fan-fang Li, Qi Hua Zhao, Hong-Ke Liu, Peter J. Sadler, Carlos Sanchez-Cano
      Two oxidovanadium(IV) complexes carrying Schiff base ligands obtained from the condensation of 4,5-dichlorobenzene-1,2-diamine and salicylaldehyde derivatives were synthesised and characterised, including their X-ray crystallographic structures. They were evaluated as dipeptidyl peptidase IV (DPP-IV) inhibitors for the treatment of type 2 diabetes. These compounds were moderate inhibitors of DPP-IV, with IC50 values of ca. 40μM. In vivo tests showed that complexes 1 and 2 could lower significantly the level of glucose in the blood of alloxan-diabetic mice at doses of 22.5mgV·kg−1 and 29.6mgV·kg−1, respectively. Moreover, molecular modeling studies suggested that the oxidovanadium complexes 1 and 2 could fit well into the active-site cleft of the kinase domain of DPP-IV. To the best of our knowledge, this is the first report of vanadium complexes capable of inhibiting DPP-IV.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.06.014
      Issue No: Vol. 175 (2017)
       
  • Electron magnetic resonance data on high-spin Mn(III; S=2) ions in
           porphyrinic and salen complexes modeled by microscopic spin Hamiltonian
           approach
    • Authors: Krzysztof Tadyszak; Czesław Rudowicz; Hitoshi Ohta; Takahiro Sakurai
      Pages: 36 - 46
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Krzysztof Tadyszak, Czesław Rudowicz, Hitoshi Ohta, Takahiro Sakurai
      The spin Hamiltonian (SH) parameters experimentally determined by EMR (EPR) may be corroborated or otherwise using various theoretical modeling approaches. To this end semiempirical modeling is carried out for high-spin (S=2) manganese (III) 3d4 ions in complex of tetraphenylporphyrinato manganese (III) chloride (MnTPPCl). This modeling utilizes the microscopic spin Hamiltonians (MSH) approach developed for the 3d4 and 3d6 ions with spin S=2 at orthorhombic and tetragonal symmetry sites in crystals, which exhibit an orbital singlet ground state. Calculations of the zero-field splitting (ZFS) parameters and the Zeeman electronic (Ze) factors (g = g z, g ⊥ = g x = g y) are carried out for wide ranges of values of the microscopic parameters using the MSH/VBA package. This enables to examine the dependence of the theoretically determined ZFS parameters b k q (in the Stevens notation) and the Zeeman factors g i on the spin-orbit (λ), spin-spin (ρ) coupling constant, and the ligand-field energy levels (Δi) within the 5D multiplet. The results are presented in suitable tables and graphs. The values of λ, ρ, and Δi best describing Mn(III) ions in MnTPPCl are determined by matching the theoretical second-rank ZFSP b2 0(D) parameter and the experimental one. The fourth-rank ZFS parameters (b4 0, b4 4) and the ρ (spin-spin)-related contributions, which have been omitted in previous studies, are considered for the first time here and are found important. Semiempirical modeling results are compared with those obtained recently by the density functional theory (DFT) and/or ab initio methods.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.06.006
      Issue No: Vol. 175 (2017)
       
  • Biotin-Pt (IV)-indomethacin hybrid: A targeting anticancer prodrug
           providing enhanced cancer cellular uptake and reversing cisplatin
           resistance
    • Authors: Weiwei Hu; Lei Fang; Wuyang Hua; Shaohua Gou
      Pages: 47 - 57
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Weiwei Hu, Lei Fang, Wuyang Hua, Shaohua Gou
      A Pt(IV) prodrug (2) composed of cancer-targeting biotin and nonsteroidal anti-inflammatory drug indomethacin in the axial positions of the six-coordinated octahedral geometry derived from cisplatin was developed, which could be highly accumulated in cancer cells more than normal ones and activated by endogenous reducing molecules to release cisplatin and indomethacin moieties simultaneously to inhibit tumor progression synergistically. In vitro assays revealed that 2 exhibited significantly selective inhibition to the tested cancer cell lines and sensitivity to cisplatin resistant cancer cells. Moreover, 2 presented cyclooxygenases inhibition properties to reduce tumor-associated inflammation, reduced the invasiveness of the highly aggressive PC-3 cells, and disrupted capillary-like tube formation in EA.hy926 cells. In all, this study offers a new strategy to enhance sensitivity and reduce toxicity of cisplatin.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.07.002
      Issue No: Vol. 175 (2017)
       
  • Platinum(II) and palladium(II) complexes of tridentate hydrazone-based
           ligands as selective guanine quadruplex binders
    • Authors: Alexander Schmidt; Rweetuparna Guha; Alexander Hepp; Jens Müller
      Pages: 58 - 66
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Alexander Schmidt, Rweetuparna Guha, Alexander Hepp, Jens Müller
      Several tridentate hydrazone-based ligands, synthesized by a condensation reaction of either 2-(1-methylhydrazinyl)pyridine or 2-(1-methylhydrazinyl)quinoline with an aldehyde (picolinaldehyde, 1H-pyrrole-2-carbaldehyde, 2-mercaptobenzaldehyde, 2-aminobenzaldehyde) have been reacted with palladium(II) and platinum(II) salts and precursor complexes to yield nine new metal complexes. These planar complexes were investigated with respect to their capability to interact with guanine quadruplex DNA. Two sequences (H-telo, derived from the human telomeric sequence, and c-myc, representing an excerpt of the promoter region of the c-Myc oncogene) were investigated. Circular dichroism (CD) spectroscopy, temperature-dependent CD spectroscopy, UV–Vis spectroscopy and a fluorescent intercalator displacement (FID) assay were applied in this respect. The spectroscopic data show that the complexes indeed interact with guanine quadruplex DNA. According to the FID assay, some of the complexes belong to the highest-affinity metal-containing quadruplex binders reported so far. Their affinity towards quadruplex DNA is up to 80-fold higher than to a reference double helix. These findings make the metal complexes good candidates as anticancer drugs, as guanine quadruplexes have been proposed as potential targets in anticancer drug design.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.07.003
      Issue No: Vol. 175 (2017)
       
  • New dinuclear palladium(II) complexes: Studies of the nucleophilic
           substitution reactions, DNA/BSA interactions and cytotoxic activity
    • Authors: Dušan Ćoćić; Snežana Jovanović; Marija Nišavić; Dejan Baskić; Danijela Todorović; Suzana Popović; Živadin D. Bugarčić; Biljana Petrović
      Pages: 67 - 79
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Dušan Ćoćić, Snežana Jovanović, Marija Nišavić, Dejan Baskić, Danijela Todorović, Suzana Popović, Živadin D. Bugarčić, Biljana Petrović
      Six new dinuclear Pd(II) complexes, [{Pd(2,2′-bipy)Cl}2(μ-pz)](ClO4)2 (Pd1), [{Pd(dach)Cl}2(μ-pz)](ClO4)2 (Pd2), [{Pd(en)Cl}2(μ-pz)](ClO4)2 (Pd3), [{Pd(2,2′-bipy)Cl}2(μ-4,4′-bipy)](ClO4)2 (Pd4), [{Pd(dach)Cl}2(μ-4,4′-bipy)](ClO4)2 (Pd5) and [{Pd(en)Cl}2(μ-4,4′-bipy)](ClO4)2 (Pd6) (where 2,2′-bipy=2,2′-bipyridyl, pz=pyrazine, dach= trans-(±)-1,2-diaminocyclohexane, en=ethylenediamine, 4,4′-bipy=4,4′-bipyridyl) have been synthesized and characterized by elemental microanalysis, IR, 1H NMR and MALDI-TOF mass spectrometry. The pK a values of corresponding diaqua complexes were determined by spectrophotometric pH titration. Substitution reactions with thiourea (Tu), l-methionine (l-Met), l-cysteine (l-Cys), l-histidine (l-His) and guanosine-5′-monophosphate (5′-GMP) were studied under the pseudo-first order conditions at pH7.2. Reactions of Pd1 with Tu, l-Met and l-Cys were followed by decomposition of complexes, while structures of dinuclear complexes were preserved during the substitution with nitrogen donors. Interactions with calf-thymus DNA (CT-DNA) were followed by absorption spectroscopy and fluorescence quenching measurements. All complexes can bind to CT-DNA exhibiting high intrinsic binding constants (K b =104–105 M−1). Competitive studies with ethidium bromide (EB) have shown that complexes can displace DNA-bound EB. High values of binding constants towards bovine serum albumin protein (BSA) indicate good binding affinity. Finally, all complexes showed moderate to high cytotoxic activity against HeLa (human cervical epithelial carcinoma cell lines) and MDA-MB-231 (human breast epithelial carcinoma cell lines) tumor cell lines inducing apoptotic type cell death, whereas normal fibroblasts were significantly less sensitive. The impact on cell cycle of these cells was distinctive, where Pd4, Pd5 and Pd6 showed the most prominent effect arresting MDA-MB-231 (human lung fibroblast cell lines) cell in G1/S phase of cell cycle.
      Graphical abstract image

      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.07.009
      Issue No: Vol. 175 (2017)
       
  • Design and reactivity of Ni-complexes using pentadentate
           neutral-polypyridyl ligands: Possible mimics of NiSOD
    • Authors: Victoria G. Snider; Erik R. Farquhar; Mark Allen; Ayah Abu-Spetani; Anusree Mukherjee
      Pages: 110 - 117
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Victoria G. Snider, Erik R. Farquhar, Mark Allen, Ayah Abu-Spetani, Anusree Mukherjee
      Superoxide plays a key role in cell signaling, but can be cytotoxic within cells unless well regulated by enzymes known as superoxide dismutases (SOD). Nickel superoxide dismutase (NiSOD) catalyzes the disproportion of the harmful superoxide radical into hydrogen peroxide and dioxygen. NiSOD has a unique active site structure that plays an important role in tuning the potential of the nickel center to function as an effective catalyst for superoxide dismutation with diffusion controlled rates. The synthesis of structural and functional analogues of NiSOD provides a route to better understand the role of the nickel active site in superoxide dismutation. In this work, the synthesis of a series of nickel complexes supported by nitrogen rich pentadentate ligands is reported. The complexes have been characterized through absorption spectroscopy, mass spectrometry, and elemental analysis. X-ray absorption spectroscopy was employed to establish the oxidation state and the coordination geometry around the metal center. The reactivity of these complexes toward KO2 was evaluated to elucidate the role of the coordination sphere in controlling superoxide dismutation reactivity.
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      PubDate: 2017-07-27T17:56:52Z
      DOI: 10.1016/j.jinorgbio.2017.07.005
      Issue No: Vol. 175 (2017)
       
  • Aryl-1H-imidazole[4,5f][1,10]phenanthroline Cu(II) complexes:
           Electrochemical and DNA interaction studies
    • Authors: Bharati S. Rajebhosale; Shivali N. Dongre; Sameer S. Deshpande; Anup N. Kate; Anupa A. Kumbhar
      Pages: 129 - 137
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Bharati S. Rajebhosale, Shivali N. Dongre, Sameer S. Deshpande, Anup N. Kate, Anupa A. Kumbhar
      The reaction of aryl imidazo[4,5f] [1,10]phenanthrolines with Cu(NO3)2 lead to the formation of Cu(II) complexes of the type [Cu(L)(NO3)2] where L=PIP, 2-(phenyl) [4,5f] imidazo phenanthroline; HPIP=2-(2-hydroxyphenyl)imidazo [4,5f] phenanthroline and NIP=2-(naphthyl) [4,5f] imidazo phenanthroline. The interaction of these complexes with calf thymus DNA has been studied using viscosity measurements, UV–visible and fluorescence spectroscopy. Chemical nuclease activity of these complexes has also been investigated. All complexes cleave DNA via oxidative pathway involving singlet oxygen. Molecular docking studies revealed that these complexes bind to DNA through minor groove.
      Graphical abstract image

      PubDate: 2017-07-27T17:56:52Z
      DOI: 10.1016/j.jinorgbio.2017.07.008
      Issue No: Vol. 175 (2017)
       
  • The influence of functional groups on the permeation and distribution of
           antimycobacterial rhodamine chelators
    • Authors: T. Moniz; A. Leite; T. Silva; P. Gameiro; M.S. Gomes; B. de Castro; M. Rangel
      Pages: 138 - 147
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): T. Moniz, A. Leite, T. Silva, P. Gameiro, M.S. Gomes, B. de Castro, M. Rangel
      We formerly hypothesized a mechanism whereby the antimycobacterial efficiency of a set of rhodamine labelled iron chelators is improved via the rhodamine fluorophore which enhances the chelators' permeation properties through membranes. To validate our hypothesis in a cellular context and to understand the influence of the structure of the fluorophore on the chelator's uptake and distribution within macrophages we now report comparative confocal microscopy studies performed with a set of rhodamine labelled chelators. We identify the functional groups of the chelator's framework that favor uptake by macrophages and conclude that the antimycobacterial effect is strongly related with the capacity of the chelator to distribute within the host cell and its compartments, a property that is closely related with the chelators' ability to interact with membranes. The quantification of the chelators' interaction with membranes was assessed through measurement of the corresponding partition constants in liposomes. The overall results support that the compounds which are preferentially taken up are the most efficient antimycobacterial chelators and for that reason we infer that the biological activity is modulated by the structural features of the fluorophore.
      Graphical abstract image

      PubDate: 2017-07-27T17:56:52Z
      DOI: 10.1016/j.jinorgbio.2017.07.017
      Issue No: Vol. 175 (2017)
       
  • Charge-transfer interactions of Cr species with DNA
    • Authors: Anna M. Nowicka; Edyta Matysiak-Brynda; Maria Hepel
      Pages: 148 - 153
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Anna M. Nowicka, Edyta Matysiak-Brynda, Maria Hepel
      Interactions of Cr species with nucleic acids in living organisms depend strongly on Cr oxidation state and the environmental conditions. As the effects of these interactions range from benign to pre-mutagenic to carcinogenic, careful assessment of the hazard they pose to human health is necessary. We have investigated methods that would enable quantifying the DNA damage caused by Cr species under varying environmental conditions, including UV, O2, and redox potential, using simple instrumental techniques which could be in future combined into a field-deployable instrumentation. We have employed electrochemical quartz crystal nanogravimetry (EQCN), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) to evaluate the extent of DNA damage expressed in terms of guanine oxidation yield (η) and changes in specific characteristics provided by these techniques. The effects of the interactions of Cr species with DNA were analyzed using a model calf thymus DNA (ctDNA) film on a gold electrode (Au@ctDNA) in different media, including: (i) Cr(VI), (ii) Cr(VI) reduced at −0.2V, (iii) Cr(III)+UV radiation+O2, and Cr(III), obtaining the η values: 7.4±1.4, 1.5±0.4, 1.1±0.31%, and 0%, respectively, thus quantifying the hazard posed. The EIS measurements have enabled utilizing the decrease in charge-transfer resistance (R ct) for ferri/ferrocyanide redox probe at an Au@ctDNA electrode to assess the oxidative ctDNA damage by Cr(VI) species. In this case, circular dichroism indicates an extensive damage to the ctDNA hydrogen bonding. On the other hand, Cr(III) species have not induced any damage to ctDNA, although the EQCN measurements show an electrostatic binding to DNA.
      Graphical abstract image

      PubDate: 2017-07-27T17:56:52Z
      DOI: 10.1016/j.jinorgbio.2017.07.019
      Issue No: Vol. 175 (2017)
       
  • Impact of the Cu(II) ions on the chemical and biological properties of
           goserelin – coordination pattern, DNA degradation, oxidative reactivity
           and in vitro cytotoxicity
    • Authors: Paulina K. Walencik; Kamila Stokowa-Sołtys; Robert Wieczorek; Urszula K. Komarnicka; Agnieszka Kyzioł; Małgorzata Jeżowska-Bojczuk
      Pages: 167 - 178
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Paulina K. Walencik, Kamila Stokowa-Sołtys, Robert Wieczorek, Urszula K. Komarnicka, Agnieszka Kyzioł, Małgorzata Jeżowska-Bojczuk
      Goserelin acetate (Gos) as a synthetic analog of the mammalian gonadotropin-releasing hormone (GnRH) is widely used in the treatment of sex hormone-related conditions. In this paper we present the chemical and biological aspects of its interaction with Cu(II) ions. The mode of Cu(II) binding and the thermodynamic stability of the obtained complexes were characterized by potentiometry, UV–Vis and CD spectroscopic methods. The DFT calculations were applied in order to investigate and confirm the molecular structure of the studied systems. The experimental and theoretical results clearly indicated the involvement of three nitrogens from the peptide and two oxygens from the acetate moieties in the Cu(II) coordination under physiological conditions. The investigated metallopeptide caused single- and/or double cleavage of the sugar-phosphate backbone of the plasmid DNA in the reaction accompanied by endogenous substances such as hydrogen peroxide or ascorbic acid. The degradation of the DNA molecule occurred via the free radical mechanism. Calculations based on measured spectra allowed determining the kinetic parameters of OH formation. The cytotoxic effects of Gos and its metallo-derivative were tested in vitro towards two cancer cell lines (A549 – human lung adenocarcinoma, CT26 – mouse colon carcinoma).
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      PubDate: 2017-07-27T17:56:52Z
      DOI: 10.1016/j.jinorgbio.2017.07.016
      Issue No: Vol. 175 (2017)
       
  • New copper(II) thiohydantoin complexes: Synthesis, characterization, and
           assessment of their interaction with bovine serum albumin and DNA
    • Authors: Ksenia Tishchenko; Elena Beloglazkina; Mikhail Proskurnin; Vladislav Malinnikov; Dmitriy Guk; Marina Muratova; Olga Krasnovskaya; Anna Udina; Dmitry Skvortsov; Radik R. Shafikov; Yan Ivanenkov; Vladimir Aladinskiy; Ivan Sorokin; Oleg Gromov; Alexander Majouga; Nikolay Zyk
      Pages: 190 - 197
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Ksenia Tishchenko, Elena Beloglazkina, Mikhail Proskurnin, Vladislav Malinnikov, Dmitriy Guk, Marina Muratova, Olga Krasnovskaya, Anna Udina, Dmitry Skvortsov, Radik R. Shafikov, Yan Ivanenkov, Vladimir Aladinskiy, Ivan Sorokin, Oleg Gromov, Alexander Majouga, Nikolay Zyk
      New copper(II) complexes of 2-alkylthio-5-arylmethylene-4H-imidazolin-4-ones: (5Z)-2-(methylsulfanyl)-3-(prop-2-en-1-yl)-5-(pyridin-2-ylmethylidene)-3,5-dihydro-4H-imidazol-4-one) (1a), (5Z,5′Z)-2,2′-(ethan-1,2-diyldisulfanyldiyl)bis(5-(2-pyridilmethylen)-3-allyl-3,5-dihydo-4Н-imidazole-4-one) (2a) and (5Z,5′Z)-3,3′-hexan-1,6-diylbis[5-(2-pyridilmethylen)-2-methylthiotetrahydro-4Н-imidazole-4-one)] (3a) were synthesized as possible anticancer drugs. Their structures were characterized by 1H NMR spectroscopy, elemental analysis, and X-ray crystallography. The composition of the complexes were found for 1a (Cu:L= 1:1), 2a (Cu:L= 2:1), and 3a (Cu:L= 2:1). The chelation constants were found by competitive complexation with ethylenediamine tetraacetate: 1a (6.7±0.6)×1015 M−1, 2a =(4.9±0.4)×1019 M−2, and 3a (5.7±0.5)×1019 M−2. Supramolecular binding with calf thymus DNA by competitive ethidium bromide quenching was made for complex 2a as the most promising anticancer model, the Stern–Volmer constants were found to be K SV =(8.0±0.4)×106 M−1, K q =(6.5±0.4)×105 M−1. The binding of the complex 2a to BSA was made by the Scatchard method, the value of the constant is K b =(1.9±0.2)×106 M−1.
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      PubDate: 2017-07-27T17:56:52Z
      DOI: 10.1016/j.jinorgbio.2017.07.015
      Issue No: Vol. 175 (2017)
       
  • Varying the metal to ethacrynic acid ratio in
           ruthenium(ii)/osmium(ii)-p-cymene conjugates
    • Authors: Emilia Păunescu; Mylène Soudani; Catherine M. Clavel; Paul J. Dyson
      Pages: 198 - 207
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Emilia Păunescu, Mylène Soudani, Catherine M. Clavel, Paul J. Dyson
      Following the identification of a ruthenium(II)-arene complex with an ethacrynic acid-modified imidazole ligand, which inhibits glutathione transferase (GST) and is cytotoxic to chemo-resistant cancer cells, a series of structurally related ruthenium(II)- and osmium(II)-p-cymene compounds have been prepared. In these complexes the ethacrynic acid is linked to the metals via appropriately modified pyridine ligands. The influence of the metal center and the metal:ethacrynic acid ratio on the cytotoxicity of the compounds was evaluated with the derivatives with one metal center and two ethacrynic acid moieties being the most potent against chemo-resistant A2780cisR cells (human ovarian cancer cells with acquired resistance to cisplatin). Moreover, compared to a complex with an ethacrynic acid-modified imidazole ligand (RAIMID-EA, Figure 2), these complexes display a significant degree of cancer cell specificity.
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      PubDate: 2017-08-06T18:32:02Z
      DOI: 10.1016/j.jinorgbio.2017.07.027
      Issue No: Vol. 175 (2017)
       
  • An essential role of N-terminal domain of copper chaperone in the
           enzymatic activation of Cu/Zn-superoxide dismutase
    • Authors: Mami Fukuoka; Eiichi Tokuda; Kenta Nakagome; Zhiliang Wu; Isao Nagano; Yoshiaki Furukawa
      Pages: 208 - 216
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Mami Fukuoka, Eiichi Tokuda, Kenta Nakagome, Zhiliang Wu, Isao Nagano, Yoshiaki Furukawa
      Cu/Zn-superoxide dismutase (SOD1) is an enzyme that disproportionates superoxide anion into hydrogen peroxide and molecular oxygen. The enzymatic activity of SOD1 requires the binding of copper and zinc ions and also the formation of a conserved intramolecular disulfide bond. In a eukaryotic cell, a copper chaperone for SOD1 (CCS) has been known to supply a copper ion and also introduce the disulfide bond into SOD1; however, a mechanism controlling the CCS-dependent activation of SOD1 remains obscure. Here, we characterized CCS isolated from a human liver fluke, Clonorchis sinensis, and found that an N-terminal domain of CCS was essential in supplying a copper ion in SOD1. Regardless of the presence and absence of the N-terminal domain, CCS was able to bind a cuprous ion at the CxC motif of its C-terminal domain with quite high affinity (K d ~10−17). The copper-bound form of full-length CCS successfully activated C. sinensis SOD1, but that of CCS lacking the N-terminal domain did not. Nonetheless, the N-terminally truncated CCS with the bound copper ion was found to correctly introduce the disulfide bond into SOD1. Based upon these results, we propose that the N-terminal domain of CCS has roles in the release of the copper ion bound at the C-terminal domain of CCS to SOD1.
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      PubDate: 2017-08-06T18:32:02Z
      DOI: 10.1016/j.jinorgbio.2017.07.036
      Issue No: Vol. 175 (2017)
       
  • Antiparasitic activity against trypanosomatid diseases and novel metal
           complexes derived from the first time characterized
           5-phenyl-1,2,4-triazolo[1,5-a]pyrimidi-7(4H)-one
    • Authors: J.M. Méndez-Arriaga; G.M. Esteban-Parra; M.J. Juárez; A. Rodríguez-Diéguez; M. Sánchez-Moreno; J. Isac-García; J.M. Salas
      Pages: 217 - 224
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): J.M. Méndez-Arriaga, G.M. Esteban-Parra, M.J. Juárez, A. Rodríguez-Diéguez, M. Sánchez-Moreno, J. Isac-García, J.M. Salas
      A serie of isostructural complexes with general formula [M(ftpO)2(H2O)4] have been obtained from reaction between the first time characterized triazolopyrimidine derivative 5-phenyl-1,2,4-triazolo[1,5-a]pyrimidi-7(4H)-one (HftpO) (1) and first row transition nitrates (M=Cu (2), Co (3), Ni (4) and Zn (5)). A copper complex with formula [Cu(HftpO)2(NO3)2(H2O)2]·H2O (6) was also isolated. HftpO and their metal complexes have been characterized by spectroscopic and thermal analysis and their crystal structures have been solved by X-ray diffraction methods. The isostructural compounds are mononuclear complexes where the triazolopyrimidine ligand acts as monodentate ligand through N3 nitrogen position. The crystal structure of these novel bis-5-phenyl-1,2,4-triazolo[1,5-a]pyrimidin-7(4H)-one-tetraaquo metal complexes offers an excellent opportunity at these complexes to acts as potential building blocks. Also, the antiparasitic activity of HftpO ligand against different leishmania and trypanosome strains has been studied.
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      PubDate: 2017-08-06T18:32:02Z
      DOI: 10.1016/j.jinorgbio.2017.07.026
      Issue No: Vol. 175 (2017)
       
  • Anti-Leishmania activity of new ruthenium(II) complexes: Effect on
           parasite-host interaction
    • Authors: Mônica S. Costa; Yasmim G. Gonçalves; Débora C.O. Nunes; Danielle R. Napolitano; Pedro I.S. Maia; Renata S. Rodrigues; Veridiana M. Rodrigues; Gustavo Von Poelhsitz; Kelly A.G. Yoneyama
      Pages: 225 - 231
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Mônica S. Costa, Yasmim G. Gonçalves, Débora C.O. Nunes, Danielle R. Napolitano, Pedro I.S. Maia, Renata S. Rodrigues, Veridiana M. Rodrigues, Gustavo Von Poelhsitz, Kelly A.G. Yoneyama
      Leishmaniasis is a parasitic disease caused by protozoa of the genus Leishmania. The many complications presented by the current treatment – including high toxicity, high cost and parasite resistance – make the development of new therapeutic agents indispensable. The present study aims to evaluate the anti-Leishmania potential of new ruthenium(II) complexes, cis‑[RuII(η2-O2CR)(dppm)2]PF6, with dppm=bis(diphenylphosphino)methane and R=4-butylbenzoate (bbato) 1, 4-(methylthio)benzoate (mtbato) 2 and 3-hydroxy-4-methoxybenzoate (hmxbato) 3, in promastigote cytotoxicity and their effect on parasite-host interaction. The cytotoxicity of complexes was analyzed by MTT assay against Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis, Leishmania (Leishmania) infantum promastigotes and the murine macrophage (RAW 264.7). The effect of complexes on parasite-host interaction was evaluated by in vitro infectivity assay performed in the presence of two different concentrations of each complex: the promastigote IC50 value and the concentration nontoxic to 90% of RAW 264.7 macrophages. Complexes 1–3 exhibited potent cytotoxic activity against all Leishmania species assayed. The IC50 values ranged from 7.52–12.59μM (complex 1); 0.70–3.28μM (complex 2) and 0.52–1.75μM (complex 3). All complexes significantly inhibited the infectivity index at both tested concentrations. The infectivity inhibitions ranged from 37 to 85%. Interestingly, the infectivity inhibitions due to complex action did not differ significantly at either of the tested concentrations, except for the complex 1 against Leishmania (Leishmania) infantum. The infectivity inhibitions resulted from reductions in both percentage of infected macrophages and number of parasites per macrophage. Taken together the results suggest remarkable leishmanicidal activity in vitro by these new ruthenium(II) complexes.
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      PubDate: 2017-08-06T18:32:02Z
      DOI: 10.1016/j.jinorgbio.2017.07.023
      Issue No: Vol. 175 (2017)
       
  • Impact of the corrin framework of vitamin B12 on the electrochemical
           carbon-skeleton rearrangement in comparison to an imine/oxime planar
           ligand; tuning selectivity in 1,2-migration of a functional group by
           controlling electrolysis potential
    • Authors: Keishiro Tahara; Ling Pan; Ryoko Yamaguchi; Hisashi Shimakoshi; Masaaki Abe; Yoshio Hisaeda
      Pages: 239 - 243
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Keishiro Tahara, Ling Pan, Ryoko Yamaguchi, Hisashi Shimakoshi, Masaaki Abe, Yoshio Hisaeda
      Among the coenzyme B12-dependent enzymes, methylmalonyl-CoA mutase (MMCM) catalyzes the carbon-skeleton rearrangement reaction between R-methylmalonyl-CoA and succinyl-CoA. Diethyl 2-bromomethyl-2-phenylmalonate, an alkyl bromide substrate having two different migrating groups (phenyl and carboxylic ester groups) on the β-carbon, was applied to the electrolysis mediated by a hydrophobic vitamin B12 model complex, heptamethyl cobyrinate perchlorate in this study. The electrolysis of the substrate at −1.0V vs. Ag-AgCl by light irradiation afforded the simple reduced product (diethyl 2-methyl-2-phenylmalonate) and the phenyl migrated product (diethyl 2-benzyl-2-phenylmalonate), as well as the electrolysis of the substrate at −1.5V vs. Ag-AgCl in the dark. The electrolysis of the substrate at −2.0V vs. Ag-AgCl afforded the carboxylic ester migrated product (diethyl phenylsuccinate) as the major product. The selectivity for the migrating group was successfully tuned by controlling the electrolysis potential. We clarified that the cathodic chemistry of the Co(III) alkylated heptamethyl cobyrinate is critical for the selectivity of the migrating group through mechanistic investigations and comparisons to the simple vitamin B12 model complex, an imine/oxime-type cobalt complex.
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      PubDate: 2017-08-16T19:14:15Z
      DOI: 10.1016/j.jinorgbio.2017.07.021
      Issue No: Vol. 175 (2017)
       
  • Silver and gold in the Protein Data Bank
    • Authors: Oliviero Carugo
      Pages: 244 - 247
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Oliviero Carugo
      The structural features of the silver and gold sites in protein crystal structures extracted from the Protein Data Bank have been investigated. It is observed that both cations have nearly always low oxidations states (+1) and low coordination numbers, adopt standard stereochemistries, and interact preferentially (particularly gold) with sulfur donor atoms of cysteine and methionine side-chains. Interestingly, gold cation have been very often refined with occupancy minor than 1.0 and are very often “naked”, in the sense that no donor atoms are sufficiently close to the metal cation. This apparently strange observation points out towards the need to develop specific and efficient validation tools for these elements when they are coordinated to proteins.
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      PubDate: 2017-08-16T19:14:15Z
      DOI: 10.1016/j.jinorgbio.2017.07.031
      Issue No: Vol. 175 (2017)
       
  • Quantum chemical study of mechanism and stereoselectivity of secondary
           alcohol dehydrogenase
    • Authors: Sara Moa; Fahmi Himo
      Pages: 259 - 266
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Sara Moa, Fahmi Himo
      Secondary alcohol dehydrogenase from Thermoanaerobacter brockii (TbSADH) is a Zn- and NADP-dependent enzyme that catalyses the reversible transformation of secondary alcohols into ketones. It is of potential biocatalytic interest as it can be used in the synthesis of chiral alcohols by asymmetric reduction of ketones. In this paper, density functional theory calculations are employed to elucidate the origins of the enantioselectivity of TbSADH using a large model of the active site and considering two different substrates, 2-butanol and 3-hexanol. For these two substrates the enzyme has experimentally been shown to have the opposite enantioselectivity. The energy profiles for the reactions are calculated and the stationary points along the reaction path are characterised. The calculations first confirm that the general mechanism proposed for other alcohol dehydrogenases is energetically viable. In this mechanism, a proton is first transferred from the substrate to a histidine residue at the surface, followed by a hydride transfer to the NADP cofactor. The calculated overall energy barrier is consistent with the measured rate constant. Very importantly, the calculations are able to reproduce and rationalise the enantioselectivity of the enzyme for both substrates. The detailed characterisation of the energies and geometries of the involved transition states will be valuable in the rational engineering of TbSADH to expand its utility in biocatalysis.
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      PubDate: 2017-08-16T19:14:15Z
      DOI: 10.1016/j.jinorgbio.2017.07.022
      Issue No: Vol. 175 (2017)
       
  • Effects of the fluorine substituent positions of the intercalating ligands
           on the binding behavior and third-strand stabilization of two Ru(II)
           complexes toward poly(U)•poly(A)*poly(U) triplex RNA
    • Authors: Mengna Peng; Wen Ni; Lifeng Tan
      Pages: 276 - 283
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Mengna Peng, Wen Ni, Lifeng Tan
      Two new Ru(II) polypyridyl complexes containing fluorine substituents, [Ru(bpy)2(o-fpip)]2+ (Ru1, bpy=2,2′-bipyridine, o-fpip=2-(2-fluorophenyl)imidazo[4,5-f] [1,10]phenanthroline) and [Ru(bpy)2(p-fpip)]2+ (Ru2, p-fpip=2-(4-fluorophenyl)imidazo[4,5-f] [1,10]phenanthroline) have been synthesized as binders for poly(U)•poly(A)∗poly(U) triplex RNA. The binding of the two complexes with the triplex RNA has been investigated by spectroscopic methods and viscosity measurements. Analysis of the electronic absorption spectra indicates that the association of intercalating Ru2 with the triplex RNA is greater than that of Ru1, which is also supported by spectroscopic titrations and viscosity measurements. Thermal denaturation studies reflect that third-strand stabilization depend on the nature of the two complexes and Ru2 is more effective for stabilization of the triplex RNA. Circular dichroism spectra of the triplex RNA in the presence of metal complexes indicate that the binding-induced CD perturbation of the triplex structure is more obvious by Ru2. The main results obtained here suggest that the positions of fluorine substituent in the intercalating ligands have a significant effect on the two complexes stabilizing the third strand.
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      PubDate: 2017-08-16T19:14:15Z
      DOI: 10.1016/j.jinorgbio.2017.08.004
      Issue No: Vol. 175 (2017)
       
  • Evaluation of the binding of four anti-tumor Casiopeínas® to
           human serum albumin
    • Authors: Isabel Correia; Sladjana Borovic; Isabel Cavaco; Cristina P. Matos; Somnath Roy; Hugo M. Santos; Luz Fernandes; José L. Capelo; Lena Ruiz-Azuara; João Costa Pessoa
      Pages: 284 - 297
      Abstract: Publication date: October 2017
      Source:Journal of Inorganic Biochemistry, Volume 175
      Author(s): Isabel Correia, Sladjana Borovic, Isabel Cavaco, Cristina P. Matos, Somnath Roy, Hugo M. Santos, Luz Fernandes, José L. Capelo, Lena Ruiz-Azuara, João Costa Pessoa
      The metal complexes designated by Casiopeínas® are mixed-ligand CuII-compounds some of them having promising antineoplastic properties. We report studies of binding of Cu(glycinato)(4,7-dimethyl-1,10-phenanthroline) (Cas-II-Gly (1)), Cu(acetylacetonato)(4,7-dimethyl-1,10-phenanthroline) (Cas-III-Ea (2)), Cu(glycinato)(4,4′-dimethyl-2,2′-bipyridine) (Cas-IV-Gly (3)) and Cu(acetylacetonato)(4,4′-dimethyl-2,2′-bipyridine) (Cas-III-ia (4)) to human serum albumin (HSA) by circular dichroism (CD), Electron paramagnetic resonance (EPR) and fluorescence spectroscopy. The results indicate that HSA may bind up to three molecules of the tested Casiopeínas. This is confirmed by inductively coupled plasma – atomic absorption spectroscopy measurements of samples of HSA-Casiopeínas after passing by adequate size-exclusion columns. The binding of Cas-II-Gly to HSA was also confirmed by MALDI-TOF mass spectrometric experiments. In the physiological range of concentrations the Casiopeínas form 1:1 adducts with HSA, with conditional binding constants of ca. 1×109 (1), 4×107 (2), 1×106 (3) and 2×105 (4), values determined from the CD spectra measured, and the fluorescence emission spectra indicates that the binding takes place close to the Trp214 residue. Overall, the data confirm that these Casiopeínas may bind to HSA and may be transported in blood serum by this protein; this might allow some selective tumor targeting, particularly in the case of Cas-II-Gly. In this work we also discuss aspects associated to the reliability of the frequently used methodologies to determine binding constants based on the measurement of fluorescence emission spectra of solutions containing low concentrations of proteins such as HSA and BSA, by titrations with solutions of metal complexes.
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      PubDate: 2017-08-16T19:14:15Z
      DOI: 10.1016/j.jinorgbio.2017.07.025
      Issue No: Vol. 175 (2017)
       
  • DNA and protein binding, double-strand DNA cleavage and cytotoxicity of
           mixed ligand copper(II) complexes of the antibacterial drug nalidixic acid
           
    • Authors: Rangasamy Loganathan; Mani Ganeshpandian; Nattamai S.P. Bhuvanesh; Mallayan Palaniandavar; Amsaveni Muruganantham; Swapan K. Ghosh; Anvarbatcha Riyasdeen; Mohammad Abdulkader Akbarsha
      Pages: 1 - 13
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): Rangasamy Loganathan, Mani Ganeshpandian, Nattamai S.P. Bhuvanesh, Mallayan Palaniandavar, Amsaveni Muruganantham, Swapan K. Ghosh, Anvarbatcha Riyasdeen, Mohammad Abdulkader Akbarsha
      The water soluble mixed ligand complexes [Cu(nal)(diimine)(H2O)](ClO4) 1–4, where H(nal) is nalidixic acid and diimine is 2,2′-bipyridine (1), 1,10-phenanthroline (2), 5,6-dimethyl-1,10-phenanthroline (3), and 3,4,7,8-tetramethyl-1,10-phenanthroline (4), have been isolated. The coordination geometry around Cu(II) in 1 and that in the Density Functional Theory optimized structures of 1–4 has been assessed as square pyramidal. The trend in DNA binding constants (K b) determined using absorption spectral titration (K b: 1, 0.79±0.1< 2, 1.06±0.1< 3, 1.79±0.2< 4, 1.84±0.2×105 M−1) is in line with that (K app) determined by competitive ethidium bromide binding studies. The large red-shift (10nm) observed for 2 suggests that the phen co-ligand is stacked with a frayed DNA base pair. In contrast, 3 and 4 are involved in intimate hydrophobic interaction with DNA through the methyl substituents on phen ring, which is supported by viscosity and protein binding studies. DNA docking studies imply that 4 is involved preferentially in DNA major groove binding while 1–3 in minor groove binding and that all the complexes, upon removing the axially coordinated water molecule, bind in the major groove. Interestingly, 3 and 4 display prominent double-strand DNA cleavage while 1 and 2 effect only single-strand DNA cleavage in the absence of an activator. The complexes 3 and 4 show cytotoxicity higher than 1 and 2 against human breast cancer cell lines (MCF-7). The complex 4 induces apoptotic mode of cell death in cancer cells.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.05.001
      Issue No: Vol. 174 (2017)
       
  • Antitumoral effect of vanadium compounds in malignant melanoma cell lines
    • Authors: Carla Rozzo; Daniele Sanna; Eugenio Garribba; Maria Serra; Alessio Cantara; Giuseppe Palmieri; Marina Pisano
      Pages: 14 - 24
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): Carla Rozzo, Daniele Sanna, Eugenio Garribba, Maria Serra, Alessio Cantara, Giuseppe Palmieri, Marina Pisano
      In this study we evaluated the anticancer activity against malignant melanoma (MM) of four different vanadium species: the inorganic anion vanadate(V) (indicated with VN), and three oxidovanadium(IV) complexes, [VIVO(dhp)2] where dhp− is the anion 1,2-dimethyl-3-hydroxy-4(1H)-pyridinonate (indicated with VS2), [VIVO(mpp)2] where mpp− is 1-methyl-3-hydroxy-4(1H)-pyridinonate (indicated with VS3), and [VIVO(ppp)2] where ppp− is 1-phenyl-2-methyl-3-hydroxy-4(1H)-pyridinonate (indicated with VS4). The antitumor effects of these compounds were studied against two different MM cell lines (A375 and CN-mel) and a fibroblast cell line (BJ) as normal control. All tested V compounds exert antiproliferative activity on MM cells in a dose dependent manner (IC50 ranges from 2.4μM up to 14μM) being A375 the most sensitive cell line. VN and VS2 were the two most active compounds against A375 (IC50 of 4.7 and 2.6μM, respectively), causing apoptosis and cell cycle block. The experimental data indicate that the cell cycle arrest occurs at different phases for the two V species analyzed (G2 checkpoint for VN and G0/G1 for VS2), showing the importance of the chemical form in determining their mechanism of action. These results add more insights into the landscape of vanadium versatility in biological systems and into its role as a potential cancer therapeutic agent.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.05.010
      Issue No: Vol. 174 (2017)
       
  • Unfolding biological properties of a versatile dicopper(II) precursor and
           its two mononuclear copper(II) derivatives
    • Authors: Anup Paul; Susanta Hazra; Gunjan Sharma; M. Fátima C. Guedes da Silva; Biplob Koch; Armando J.L. Pombeiro
      Pages: 25 - 36
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): Anup Paul, Susanta Hazra, Gunjan Sharma, M. Fátima C. Guedes da Silva, Biplob Koch, Armando J.L. Pombeiro
      Synthesis, inter-conversions and biological study of the dichloro bridged dicopper(II) compound [CuLCl]2 (1) and its two mononuclear derivatives [CuLCl(H2O)]·H2O (2) and [CuLCl(py)] (3) (HL=2-(2-pyridylmethyleneamino)benzenesulfonic acid) are described. The dimeric compound 1 collapses into monomers 2 and 3 in the presence of coordinating solvents, water and pyridine, respectively, and 1 is regenerated upon simple stirring of 2 or 3 in methanol. The reactions of 1 with neutral (present study) and charged (earlier studies) ligands result in monomeric and multimeric compounds, respectively, attesting that it is a versatile dicopper(II) precursor. The anticancer activity of these copper complexes (1–3) was screened against lung (A-549) and breast (MDA-MB-231) human cancer cell lines. The IC50 (half maximal inhibitory concentration) value for one (3) of the compounds suggests preferential cytotoxicity against breast cancer MDA-MB-231 cell line. Furthermore, the IC50 value obtained for complex 3 is found to be almost two-fold times cytotoxic than the standard drug cisplatin. In addition, the underlying possible mechanism of its apoptosis-inducing efficacy in MDA-MB-231 cells has been rationalized by using flow cytometry (FACS) and Hoechst 33342/propidium iodide (PI) fluorescence staining. The stimulation of apoptotic induction for complex 3 has further been affirmed by reactive oxygen species (ROS) generation and mitochondrial aggregations studies.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.05.013
      Issue No: Vol. 174 (2017)
       
  • Negligible interaction of [Ru(Phen)3]2+ with human serum albumin makes it
           promising for a reliable in vivo assessment of the tissue oxygenation
    • Authors: Dominik Belej; Zuzana Jurasekova; Michal Nemergut; Georges Wagnieres; Daniel Jancura; Veronika Huntosova
      Pages: 37 - 44
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): Dominik Belej, Zuzana Jurasekova, Michal Nemergut, Georges Wagnieres, Daniel Jancura, Veronika Huntosova
      The interaction between a ruthenium - based water soluble oxygen probe ([Ru(Phen)3]2+, phen - phenanthroline) and human serum albumin (HSA) was investigated with the aim of describing the influence of HSA on the [Ru(Phen)3]2+ luminescence properties. Nowadays, several oxygen sensitive luminescent probes are used to determine the oxygen level in different compartments of living organisms. However, they can interact, depending on their hydrophilic/hydrophobic characters, with various serum proteins, and/or lipids, during their utilization for in vivo oxygen measurement. Since HSA is the most abundant serum protein in most biological organisms, its presence may affect the spectral properties of the employed probes and, consequently, the determination of the oxygen concentration. Having this in mind, we have applied several spectroscopic and calorimetric techniques to study [Ru(Phen)3]2+ - HSA mixtures. Only a negligible effect of HSA on the absorption and luminescence spectra of [Ru(Phen)3]2+ was observed. In addition, differential scanning calorimetric studies showed that [Ru(Phen)3]2+ does not significantly influence HSA thermal stability. Importantly, [Ru(Phen)3]2+ retained a reliable luminescence lifetime sensitivity to the oxygen concentration in solutions supplemented with HSA and in U87 MG cancer cells. Finally, the biodistribution of [Ru(Phen)3]2+ in the presence of serum proteins in the blood stream of chick embryo's chorioallantoic membrane (CAM) was investigated. Fast [Ru(Phen)3]2+ and similar extravasations were observed in the presence or absence of CAM-serum. We can conclude that HSA-[Ru(Phen)3]2+ complex interaction does not significantly influence the potential of [Ru(Phen)3]2+ to be a suitable candidate for a reliable oxygen probe in living organisms.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.05.016
      Issue No: Vol. 174 (2017)
       
  • Terpyridyl oxovanadium(IV) complexes for DNA crosslinking and
           mito-targeted photocytotoxicity
    • Authors: Arun Kumar; Ila Pant; Akanksha Dixit; Samya Banerjee; Bhabatosh Banik; Rupak Saha; Paturu Kondaiah; Akhil R. Chakravarty
      Pages: 45 - 54
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): Arun Kumar, Ila Pant, Akanksha Dixit, Samya Banerjee, Bhabatosh Banik, Rupak Saha, Paturu Kondaiah, Akhil R. Chakravarty
      Oxovanadium(IV) complexes [VO(L1/L2)Cl2]n+ (1,2) of (anthracenyl)terpyridine (An-tpy as L1 in 1, n=0) and triphenylphosphonium-appended (anthracenyl)terpyridine (An-tpy-TPP+ as L2 in 2, n=1) were synthesized, characterized and their DNA crosslinking ability, photocytotoxicity in visible light and cellular localization in cancer cells studied. The bromide derivative of 2, viz. [VO(An-tpy-TPP)Br2]Br (3) is structurally characterized. The structure showed trans disposition of two halides in the coordination sphere and the TPP+ unit is a pendant to the terpyridyl ligand. The DNA melting and comet assay studies on the complexes suggest the formation of DNA crosslinks. Complexes 1 and 2 displayed ~10 fold increase in cytotoxicity on exposure to visible light (400–700nm) when compared to those in dark in HeLa and MCF-7 cells. FACScan (Fluorescence Associated Cell Sorter Scan) analysis showed cellular apoptosis when treated with the complex in visible light in comparison to their dark controls. Fluorescence microscopic studies using complex 2 revealed its mitochondrial localization within the cancer cells.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.05.015
      Issue No: Vol. 174 (2017)
       
  • Aluminum chloride caused liver dysfunction and mitochondrial energy
           metabolism disorder in rat
    • Authors: Feibo Xu; Yanfen Liu; Hansong Zhao; Kaiyuan Yu; Miao Song; Yanzhu Zhu; Yanfei Li
      Pages: 55 - 62
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): Feibo Xu, Yanfen Liu, Hansong Zhao, Kaiyuan Yu, Miao Song, Yanzhu Zhu, Yanfei Li
      Aluminum (Al) is known to exert hepatotoxicity. However, the mechanisms mostly are unclear. Liver is a metabolism organ that maintains the energy level and structural stability of body, mitochondria are the main sites of energy metabolism, thus, we hypothesized that mitochondrial energy metabolism disorder contributes to liver dysfunction in aluminum chloride (AlCl3) treatment rat. To verify the hypothesis, forty male Wistar rats were randomly allocated and orally exposed to 0, 64mg/kg, 128mg/kg and 256mg/kg body weight AlCl3 in drinking water for 120days, respectively. We found that AlCl3 exposure reduced the electron transport chain complexes I–V activities and adenosine triphosphate (ATP) level, as well as disturbed mitochondrial DNA transcript, presenting as the inhibited mRNA expressions of NADH dehydrogenase 1, NADH dehydrogenase 2, cytochrome b, cytochrome c oxidase subunit 1, cytochrome c oxidase subunit 3 and ATP synthase 6, indicating that AlCl3 exposure disturbs the mitochondrial energy metabolism, and it caused an increase in liver enzymes (Aspartate aminotransferase and Alanine aminotransferase) and histopathological lesions. Additionally, we found that reactive oxygen species accumulation and decreased superoxide dismutase activity in mitochondria, and increased 8-Hydroxydeoxyguanosine levels in mitochondrial DNA, demonstrating AlCl3 exposure promotes mitochondrial oxidative stress, which may be a contributing factor to mitochondrial energy metabolism disorder and liver dysfunction. The study displayed that mitochondria are the potential target of liver damage induced by AlCl3, providing considerable direction for the prevention and clinical intervention of liver diseases.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.04.016
      Issue No: Vol. 174 (2017)
       
  • New Cu(II) complexes with pyrazolyl derived Schiff base ligands: Synthesis
           and biological evaluation
    • Authors: Nádia Ribeiro; Somnath Roy; Nataliya Butenko; Isabel Cavaco; Teresa Pinheiro; Irina Alho; Fernanda Marques; Fernando Avecilla; João Costa Pessoa; Isabel Correia
      Pages: 63 - 75
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): Nádia Ribeiro, Somnath Roy, Nataliya Butenko, Isabel Cavaco, Teresa Pinheiro, Irina Alho, Fernanda Marques, Fernando Avecilla, João Costa Pessoa, Isabel Correia
      Since the discovery of cisplatin there has been a continuous pursuit for new metallodrugs showing higher efficacies and lower side effects. In this work, new copper(II) complexes (C1–C6) of Schiff bases derived from pyrazolyl were developed. Through condensation of 5-methyl-1H-pyrazole-3-carbohydrazide with different aromatic aldehydes – pyridoxal, salicylaldehyde, 3-methoxy-2-hydroxybenzaldehyde, 3-ethoxy-2-hydroxybenzaldehyde and 2-hydroxynaphthene-1-carbaldehyde – a set of new pyrazole based “ONO” tridentate Schiff bases were obtained in moderate to good yields – L1–L6, as well as their Cu(II)-complexes. All compounds were characterized by analytical techniques and their molecular formulae established. The antioxidant potential of all compounds was tested, yielding low activity in most cases, with the exception of L1 and C5. The Cu(II) complexes were tested for their aqueous stability, and for their interaction with biological molecules, namely DNA and HSA (human serum albumin), through fluorescence quenching experiments (and electrophoresis for DNA). With the exception of C3, all the synthesized complexes were able to interact with DNA and HSA. Their cytotoxic activity against two cancer cell lines (MCF7 — breast and PC3 — prostate) was also evaluated. Complexes C5 and C6, with larger aromatic systems, showed much higher cytotoxicity (in the low μM range), than C1–C4, as well as IC50 values much lower than cisplatin. For C6 the results suggest that the mechanisms of cell death do not seem to be mediated by apoptosis, through caspases 3/7 activation, but by involving membrane potential and imbalance in physiological elements such as P, K and Ca.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.05.011
      Issue No: Vol. 174 (2017)
       
  • Evidence of promising biological-pharmacological activities of the
           sertraline-based copper complex: (SerH2)2[CuCl4]
    • Authors: Nancy Martini; Juliana E. Parente; Maria Eugenia Toledo; Graciela E. Escudero; Carlos H. Laino; Juan José Martínez Medina; Gustavo A. Echeverría; Oscar E. Piro; Luis Lezama; Patricia A.M. Williams; Evelina G. Ferrer
      Pages: 76 - 89
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): Nancy Martini, Juliana E. Parente, Maria Eugenia Toledo, Graciela E. Escudero, Carlos H. Laino, Juan José Martínez Medina, Gustavo A. Echeverría, Oscar E. Piro, Luis Lezama, Patricia A.M. Williams, Evelina G. Ferrer
      In the current study the ability of copper complex to exert multiple biological activities is combined with the pharmacological action of sertraline (SerH2Cl, antidepressant drug). The hydrated and anhydrous forms of the tetrachlorocuprate(II) salts, namely (SerH2)2[CuCl4]·½H2O and (SerH2)2[CuCl4], were synthesized and characterized by physicochemical methods. The crystal structures were determined by X-ray diffraction methods. The hydrate complex crystallizes in the monoclinic P21 space group with a =8.0807(2) Å, b =36.2781(8) Å, c =12.6576(3) Å, β =95.665(2)°, and Z =4 molecules per unit cell and the un-hydrate in P21 with a =13.8727(6) Å, b =7.5090(3) Å, c =18.618(1) Å, β =104.563(6)°, and Z =2. It has been suggested that Cu(II) ions might be critical in the development of mood disorders, showed potent biocidal activity, and also acted as analgesic adjuvant. To improve sertraline efficiency, the antidepressant and analgesic activities of the complex have been assessed in rats denoting a marked synergistic effect. Antithyroid and antimicrobial activities were also evaluated. Because depressive disorders and hyperthyroidism diseases led to an oxidative stress state, antioxidant capability has also been tested. The complex behaved as a good superoxide radical scavenger (IC50 =6.3×10−6 M). The ability of the complex to act as bromoperoxidase mimic was assessed. A pseudo-first order constant of k =0.157±0.007min−1 has been determined. The complex evidences promising biological-pharmacological activities and the albumin binding studies showed a Kb of 2.90×103 M−1 showing an improvement in the uptake of sertraline by albumin at 8h incubation (time required for effective interaction of sertraline with the protein).
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.05.012
      Issue No: Vol. 174 (2017)
       
  • New imidoyl-indazole platinum (II) complexes as potential anticancer
           agents: Synthesis, evaluation of cytotoxicity, cell death and
           experimental-theoretical DNA interaction studies
    • Authors: Alan R. Cabrera; Christian Espinosa-Bustos; Mario Faúndez; Jaime Meléndez; Pablo Jaque; Constantin G. Daniliuc; Adam Aguirre; Rene S. Rojas; Cristian O. Salas
      Pages: 90 - 101
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): Alan R. Cabrera, Christian Espinosa-Bustos, Mario Faúndez, Jaime Meléndez, Pablo Jaque, Constantin G. Daniliuc, Adam Aguirre, Rene S. Rojas, Cristian O. Salas
      Four new neutral N,N imidoyl-indazole ligands (L1, L3, L6, L7) and six new Pt(II)-based complexes (C1–5 and C7) were synthesized and characterized by spectroscopic and spectrometric techniques. Additionally, compounds L6, L7, C3, C5 and C7 were analyzed using X-ray diffraction. An evaluation of cytotoxicity and cell death in vitro for both ligands and complexes was performed by colorimetric assay and flow cytometry, in four cancer cell lines and VERO cells as the control, respectively. Cytotoxicity and selectivity demonstrated by each compound were dependent on the cancer cell line assayed. IC50 values of complexes C1–5 and C7 were lower than those exhibited for the reference drug cisplatin, and selectivity of these complexes was in general terms greater than cisplatin on three cancer cell lines studied. In HL60 cells, complexes C1 and C5 exhibited the lowest values of IC50 and were almost five times more selective than cisplatin. Flow cytometry results suggest that each complex predominantly induced necrosis, and its variant necroptosis, instead of apoptosis in all cancer cell lines studied. DNA binding assays, using agarose gel electrophoresis and UV–visible spectrophotometry studies, displayed a strong interaction only between C4 and DNA. In fact, theoretical calculations showed that C4-DNA binding complex was the most thermodynamic favorable interaction among the complexes in study. Overall, induction of cell death by dependent and independent-DNA-metal compound interactions were possible using imidoyl-indazole Pt(II) complexes as anticancer agents.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.06.001
      Issue No: Vol. 174 (2017)
       
  • Anticancer activity of hydroxy- and sulfonamide-azobenzene platinum(II)
           complexes in cisplatin-resistant ovarian cancer cells
    • Authors: Katia G. Samper; Sierra C. Marker; Pau Bayón; Samantha N. MacMillan; Ivan Keresztes; Òscar Palacios; Justin J. Wilson
      Pages: 102 - 110
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): Katia G. Samper, Sierra C. Marker, Pau Bayón, Samantha N. MacMillan, Ivan Keresztes, Òscar Palacios, Justin J. Wilson
      The syntheses of three platinum(II) complexes bearing sulfonamide- ( (E)-2-(4-methylphenylsulfonamido)-2′,6′-difluoroazobenzene, HL1) and hydroxy-azo-2,6-difluorobenzene ((E)-2-((2,6-difluorophenyl)diazenyl)phenol, HL2) bidentate ligands is described. These complexes, [Pt(L1)(DMSO)Cl] (1), [Pt(L2)(DMSO)Cl] (2), and [Pt(L2)2] (3), were characterized by multinuclear NMR spectroscopy, mass spectrometry, and X-ray crystallography. Despite bearing azobenzene functional groups, none of the three complexes undergo photoisomerization. The anticancer activities of these complexes were evaluated in wild-type (A2780) and cisplatin-resistant (A2780CP70) ovarian cancer cells. All three complexes exhibited IC50 values below 10μM and displayed similar activity in both A2780 and A2780CP70 cell lines, indicating that they are not cross-resistant with cisplatin. The DNA-binding properties of 1–3 were investigated by circular dichroism spectroscopy and by agarose gel electrophoresis. Both studies suggest that 1 and 2 form monofunctional DNA adducts.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.06.003
      Issue No: Vol. 174 (2017)
       
  • Effect of electronic and steric properties of 8-substituted quinolines in
           gold(III) complexes: Synthesis, electrochemistry, stability, interactions
           and antiproliferative studies
    • Authors: Antonio Casado-Sánchez; Cecilia Martín-Santos; José M. Padrón; Rubén Mas-Ballesté; Carmen Navarro-Ranninger; José Alemán; Silvia Cabrera
      Pages: 111 - 118
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): Antonio Casado-Sánchez, Cecilia Martín-Santos, José M. Padrón, Rubén Mas-Ballesté, Carmen Navarro-Ranninger, José Alemán, Silvia Cabrera
      In this work the synthesis and characterization of new gold(III) complexes with quinoline ligands are described. These complexes contain different steric and electronic properties of the donor atom at 8-position of the quinoline in order to modulate their stability and their biological activity. Their redox potential, stability in organic and aqueous solvents, and their biological activity in a panel of six different human tumor cell lines are also presented. In addition, interaction studies of the complexes with model biological molecules (pBR322 and L-acetyl-N-cysteine) were carried out, suggesting that their main target are proteins. From these studies, we have found that the gold(III) complex with an N-tosyl-8-aminoquinoline ligand is the most active complex in all the tumor cell lines, including the cisplatin resistant T-47D and WiDr cell lines. Moreover, this complex showed to be the most stable compound in DMSO and saline solution, even after several hours.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.06.004
      Issue No: Vol. 174 (2017)
       
  • Impact of the equatorial coordination sphere on the rate of reduction,
           lipophilicity and cytotoxic activity of platinum(IV) complexes
    • Authors: Doris Höfer; Hristo P. Varbanov; Michaela Hejl; Michael A. Jakupec; Alexander Roller; Markus Galanski; Bernhard K. Keppler
      Pages: 119 - 129
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): Doris Höfer, Hristo P. Varbanov, Michaela Hejl, Michael A. Jakupec, Alexander Roller, Markus Galanski, Bernhard K. Keppler
      The impact of the equatorial coordination sphere on the reduction behavior (i.e. rate of reduction) of platinum(IV) complexes with axial carboxylato ligands was studied. Moreover, the influence of equatorial ligands on the stability, lipophilicity and cytotoxicity of platinum(IV) compounds was evaluated. For this purpose, a series of platinum(IV) complexes featuring axial carboxylato ligands (succinic acid monoesters) was synthesized; anionic carboxylato (OAc−, oxalate) and halido (Cl−, Br−, I−) ligands served as leaving groups and am(m)ine carrier ligands were provided by monodentately (isopropylamine, ammine+cyclohexaneamine) or bidentately (ethane-1,2-diamine) coordinating am(m)ines. All platinum(IV) products were fully characterized based on elemental analysis, high resolution mass spectrometry and multinuclear (1H, 13C, 15N, 195Pt) NMR spectroscopy as well as by X-ray diffraction in some cases. The rate of reduction in the presence of ascorbic acid was determined by NMR spectroscopy and the lipophilicity of the complexes was investigated by analytical reversed phase HPLC measurements. Cytotoxic properties were studied by means of a colorimetric microculture assay in three human cancer cell lines derived from cisplatin sensitive ovarian teratocarcinoma (CH1/PA-1) as well as cisplatin insensitive colon carcinoma (SW480) and non-small cell lung cancer (A549).
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.06.005
      Issue No: Vol. 174 (2017)
       
  • Covalent modifications of the amyloid beta peptide by hydroxynonenal:
           Effects on metal ion binding by monomers and insights into the fibril
           topology
    • Authors: G. Grasso; H. Komatsu; P.H. Axelsen
      Pages: 130 - 136
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): G. Grasso, H. Komatsu, P.H. Axelsen
      Amyloid β peptides (Aβ) and metal ions are associated with oxidative stress in Alzheimer's disease (AD). Oxidative stress, acting on ω-6 polyunsaturated fatty acyl chains, produces diverse products, including 4-hydroxy-2-nonenal (HNE), which can covalently modify the Aβ that helped to produce it. To examine possible feedback mechanisms involving Aβ, metal ions and HNE production, the effects of HNE modification and fibril formation on metal ion binding was investigated. Results indicate that copper(II) generally inhibits the modification of His side chains in Aβ by HNE, but that once modified, copper(II) still binds to Aβ with high affinity. Fibril formation protects only one of the three His residues in Aβ from HNE modification, and this protection is consistent with proposed models of fibril structure. These results provide insight into a network of biochemical reactions that may be operating as a consequence of oxidative stress in AD, or as part of the pathogenic process.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.06.007
      Issue No: Vol. 174 (2017)
       
  • Synthesis, characterization and crystal structures of two
           pentagonal-bipyramidal Fe(III) complexes with dihydrazone of
           2,6-diacetylpyridine and Girard's T reagent. Anticancer properties of
           various metal complexes of the same ligand
    • Authors: Katarina Anđelković; Milica R. Milenković; Andrej Pevec; Iztok Turel; Ivana Z. Matić; Miroslava Vujčić; Dušan Sladić; Dušanka Radanović; Gabrijela Brađan; Svetlana Belošević; Božidar Čobeljić
      Pages: 137 - 149
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): Katarina Anđelković, Milica R. Milenković, Andrej Pevec, Iztok Turel, Ivana Z. Matić, Miroslava Vujčić, Dušan Sladić, Dušanka Radanović, Gabrijela Brađan, Svetlana Belošević, Božidar Čobeljić
      In this work synthesis, characterization and crystal structures of two isothiocyanato Fe(III) complexes with 2,2′-[2,6-pyridinediylbis(ethylidyne-1-hydrazinyl-2-ylidene)]bis[N,N,N-trimethyl-2-oxoethanaminium] dichloride (H 2 LCl2) ligand, with composition [FeL(NCS)2]SCN·2H2O and [FeL(NCS)2]2[Fe(H2O)(NCS)5]·4H2O, has been reported. Both iron(III) complexes possess the same pentagonal-bipyramidal complex cation, while the nature of their anions depends on mole ratio of NH4SCN and FeCl3·6H2O used in reaction. Cytotoxic activity of new Fe(III) complexes, as well as of previously synthesized isothiocyanato Co(II), Ni(II), Mn(II), Zn(II) and Cd(II) complexes with the same ligand, was tested against five human cancer cell lines (HeLa, MDA-MB-453, K562, LS174 and A549) and normal cell line MRC-5. The best activity was observed in the case of Fe(III), Co(II) and Cd(II) complexes. The investigation of potential of these complexes to induce HeLa and K562 cell cycle perturbations was also evaluated. Mechanism of cell death mode was elucidated on the basis of morphological changes of HeLa cells as well as identification of target caspases. It was established that DNA damage could be responsible for the activity of Fe(III) and Co(II) complexes. Synopsis Pentagonal-bipyramidal Fe(III) complexes with dihydrazone of 2,6-diacetylpyridine and Girard's T reagent have been synthesized and characterized. Cytotoxic activity of Fe(III) complexes and Co(II), Ni(II), Mn(II), Zn(II) and Cd(II) complexes with the same ligand was tested. The best activity was observed in the case of Fe(III), Co(II) and Cd(II) complexes.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.06.011
      Issue No: Vol. 174 (2017)
       
  • Mononuclear gold(III) complexes with phenanthroline ligands as efficient
           inhibitors of angiogenesis: A comparative study with auranofin and
           sunitinib
    • Authors: Aleksandar Pavic; Biljana Đ. Glišić; Sandra Vojnovic; Beata Warżajtis; Nada D. Savić; Marija Antić; Slavko Radenković; Goran V. Janjić; Jasmina Nikodinovic-Runic; Urszula Rychlewska; Miloš I. Djuran
      Pages: 156 - 168
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): Aleksandar Pavic, Biljana Đ. Glišić, Sandra Vojnovic, Beata Warżajtis, Nada D. Savić, Marija Antić, Slavko Radenković, Goran V. Janjić, Jasmina Nikodinovic-Runic, Urszula Rychlewska, Miloš I. Djuran
      Gold(III) complexes with 1,7- and 4,7-phenanthroline ligands, [AuCl3(1,7-phen-κN7)] (1) and [AuCl3(4,7-phen-κN4)] (2) were synthesized and structurally characterized by spectroscopic (NMR, IR and UV–vis) and single-crystal X-ray diffraction techniques. In these complexes, 1,7- and 4,7-phenanthrolines are monodentatedly coordinated to the Au(III) ion through the N7 and N4 nitrogen atoms, respectively. In comparison to the clinically relevant anti-angiogenic compounds auranofin and sunitinib, gold(III)-phenanthroline complexes showed from 1.5- to 20-fold higher anti-angiogenic potential, and 13- and 118-fold lower toxicity. Among the tested compounds, complex 1 was the most potent and may be an excellent anti-angiogenic drug candidate, since it showed strong anti-angiogenic activity in zebrafish embryos achieving IC50 value (concentration resulting in an anti-angiogenic phenotype at 50% of embryos) of 2.89μM, while had low toxicity with LC50 value (the concentration inducing the lethal effect of 50% embryos) of 128μM. Molecular docking study revealed that both complexes and ligands could suppress angiogenesis targeting the multiple major regulators of angiogenesis, such as the vascular endothelial growth factor receptor (VEGFR-2), the matrix metalloproteases (MMP-2 and MMP-9), and thioredoxin reductase (TrxR1), where the complexes showed higher binding affinity in comparison to ligands, and particularly to auranofin, but comparable to sunitinib, an anti-angiogenic drug of clinical relevance.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.06.009
      Issue No: Vol. 174 (2017)
       
  • Controlling gold nanoparticle seeded growth in thermophilic ferritin
           protein templates
    • Authors: Katherine W. Pulsipher; Stephanie Honig; Sunbin Deng; Ivan J. Dmochowski
      Pages: 169 - 176
      Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): Katherine W. Pulsipher, Stephanie Honig, Sunbin Deng, Ivan J. Dmochowski
      Ferritin protein cages provide templates for inorganic nanoparticle synthesis in more environmentally-friendly conditions. Thermophilic ferritin from Archaeoglobus fulgidus (AfFtn) has been shown to encapsulate pre-formed 6-nm gold nanoparticles (AuNPs) and template their further growth within its 8-nm cavity. In this study, we explore whether using a gold complex with electrostatic complementarity to the anionic ferritin cavity can promote efficient seeded nanoparticle growth. We also compare wt AfFtn and a closed pore mutant AfFtn to explore whether the ferritin pores influence final AuNP size.
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      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.06.012
      Issue No: Vol. 174 (2017)
       
  • An XAS investigation of the nickel site structure in the transcriptional
           regulator InrS
    • Authors: Carolyn E. Carr; Andrew W. Foster; Michael J. Maroney
      Abstract: Publication date: Available online 10 August 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Carolyn E. Carr, Andrew W. Foster, Michael J. Maroney
      InrS (Internal nickel-responsive Sensor) is a transcriptional repressor of the nickel exporter NrsD and de-represses expression of the exporter upon binding Ni(II) ions. Although a crystal structure of apo-InrS has been reported, no structure of the protein with metal ions bound is available. Herein we report the results of metal site structural investigations of Ni(II) and Cu(II) complexes of InrS using X-ray absorption spectroscopy (XAS) that are complementary to data available from the apo-InrS crystal structure, and are consistent with a planar four-coordinate [Ni(His)2(Cys)2] structure, where the ligands are derived from the side chains of His21, Cys53, His78, and Cys82. Coordination of Cu(II) to InrS forms a nearly identical planar four-coordinate complex that is consistent with a simple replacement of the Ni(II) center by Cu(II).
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      PubDate: 2017-08-16T19:14:15Z
      DOI: 10.1016/j.jinorgbio.2017.08.003
       
  • Speciation of the trivalent f-elements Eu(III) and Cm(III) in digestive
           media
    • Authors: Claudia Wilke; Astrid Barkleit; Thorsten Stumpf; Atsushi Ikeda-Ohno
      Abstract: Publication date: Available online 4 August 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Claudia Wilke, Astrid Barkleit, Thorsten Stumpf, Atsushi Ikeda-Ohno
      In case radioactive materials are released into the environment, their incorporation into our digestive system would be a significant concern. Trivalent f-elements, i.e., trivalent actinides and lanthanides, could potentially represent a serious health risk due to their chemo- and radiotoxicity, nevertheless the biochemical behavior of these elements are mostly unknown even to date. This study, therefore, focuses on the chemical speciation of trivalent f-elements in the human gastrointestinal tract. To simulate the digestive system artificial digestive juices (saliva, gastric juice, pancreatic juice and bile fluid) were prepared. The chemical speciation of lanthanides (as Eu(III)) and actinides (as Cm(III)) was determined experimentally by time-resolved laser-induced fluorescence spectroscopy (TRLFS) and the results were compared with thermodynamic modelling. The results indicate a dominant inorganic species with phosphate/carbonate in the mouth, while the aquo ion is predominantly formed with a minor contribution of the enzyme pepsin in the stomach. In the intestinal tract the most significant species are with the protein mucin. We demonstrated the first experimental results on the chemical speciation of trivalent f-elements in the digestive media by TRLFS. The results highlight a significant gap in chemical speciation between experiments and thermodynamic modelling due to the limited availability of thermodynamic stability constants particularly for organic species. Chemical speciation strongly influences the in vivo behavior of metal ions. Therefore, the results of this speciation study will help to enhance the assessment of health risks and to improve decorporation strategies after ingestion of these (radio-) toxic heavy metal ions.
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      PubDate: 2017-08-06T18:32:02Z
      DOI: 10.1016/j.jinorgbio.2017.07.020
       
  • Mixed ligand aroylhydrazone and N-donor heterocyclic Lewis base Cu(II)
           complexes as potential antiproliferative agents
    • Authors: Manas Sutradhar; Rajeshwari; Tannistha Roy Barman; Alexandra R. Fernandes; Fabiana Paradinha; Catarina Roma-Rodrigues; M. Fátima C. Guedes da Silva; Armando J.L. Pombeiro
      Abstract: Publication date: Available online 2 August 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Manas Sutradhar, Rajeshwari, Tannistha Roy Barman, Alexandra R. Fernandes, Fabiana Paradinha, Catarina Roma-Rodrigues, M. Fátima C. Guedes da Silva, Armando J.L. Pombeiro
      A series of four mixed ligand aroylhydrazone and N-donor heterocyclic Lewis base Cu(II) complexes [CuL(X)]2 [L refers to the dianionic form of (5-bromo-2-hydroxybenzylidene)-2-hydroxybenzohydrazide; X=pyrazine (Pz; 1), pyridine (Py; 2), imidazole (Imz; 3) and 3-pyridinecarbonitrile (3-PyCN; 4)] has been synthesized and characterized by elemental analysis, various spectroscopic techniques and X-ray crystallography (for 1, 2 and 4). The antiproliferative effect of complexes 1– 4 was examined in 4 human tumor cell lines (ovarian carcinoma (A2780), colorectal carcinoma (HCT116), lung adenocarcinoma (A549) and breast adenocarcinoma (MCF7)) and in normal human primary Fibroblasts. Complex 4 exhibits a high cytotoxic activity against ovarian and colorectal carcinoma cells (A2780, HCT116 respectively), with IC50 much lower than those for normal primary fibroblasts. Complex 4 could induce cell death via apoptosis but not autophagy in colorectal carcinoma cells.
      Graphical abstract image

      PubDate: 2017-08-06T18:32:02Z
      DOI: 10.1016/j.jinorgbio.2017.07.034
       
  • IFC
    • Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174


      PubDate: 2017-07-20T17:35:45Z
       
  • Zn(II) - pramlintide: Stability, binding sites and unexpected aggregation
    • Abstract: Publication date: September 2017
      Source:Journal of Inorganic Biochemistry, Volume 174
      Author(s): D. Łoboda, M. Rowińska-Żyrek
      Pramlintide is an antidiabetic drug which mimics amylin – a small peptide co-secreted from pancreatic β-cells together with insulin, one of the hallmarks of type 2 diabetes. In the course of the disease, amylin misfolds into small oligomers or to an aggregated β-sheet amyloid fiber. The misfolding mechanism is not yet quite understood, but it is clear that zinc ions play an important role in the process. This work sheds new light on the role of zinc and pramlintide in the course of the disease, giving a detailed description of the Zn(II)-pramlintide complex, in which the metal ion binds to the imidazole of His18 and the amine group of Lys1, imposing a bend in the peptide between these residues. The most surprising finding is the fact that the initially well-soluble, non-aggregating Zn(II)-pramlintide complex forms fibrillar, oligomeric aggregates after a lag-time of 20h. This raises more questions about the relationship between Zn(II) and amylin/pramlintide: could this zinc-induced change in the complex structure be a partial explanation of the formation of oligomeric aggregates of the complex, which might be much more toxic to β-cells than large fibrillar deposits and if so, is pramlintide the optimal choice of an antidiabetic drug?
      Graphical abstract image

      PubDate: 2017-07-20T17:35:45Z
       
  • PML-RARα stabilized by zinc in human acute promyelocytic leukemia NB4
           cells
    • Authors: Bo Zhu; Jia-yu Wang; Jun-jie Zhou; Feng Zhou; Wei Cheng; Ying-ting Liu; Jie Wang; Xiao Chen; Dian-hua Chen; Lan Luo; Zi-Chun Hua
      Abstract: Publication date: Available online 19 July 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Bo Zhu, Jia-yu Wang, Jun-jie Zhou, Feng Zhou, Wei Cheng, Ying-ting Liu, Jie Wang, Xiao Chen, Dian-hua Chen, Lan Luo, Zi-Chun Hua
      Acute promyelocytic leukemia (APL) is characterized and driven by the promyelocytic leukemia protein-retinoic acid receptor alpha (PML-RARα) fusion gene. Previous studies have highlighted the importance of PML-RARα degradation in the treatment against APL. Considering the presence of two zinc fingers in the PML-RARα fusion protein, we explored the function of zinc homeostasis in maintaining PML-RARα stability. We demonstrated for the first time that zinc depletion by its chelator N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) triggered PML-RARα degradation in NB4 APL cells via the proteasome pathway rather than the autophagy-lysosomal pathway. In contrast, autophagy protected TPEN-mediated PML-RARα degradation in NB4 APL cells. We further demonstrated that crosstalk between zinc homeostasis and nitric oxide pathway played a key role in maintaining PML-RARα stability in NB4 APL cells. These results demonstrate that zinc homeostasis is vital for maintaining PML-RARα stability, and zinc depletion by TPEN may be useful as a potential strategy to trigger PML-RARα degradation in APL cells. We also found that TPEN triggered apoptosis of NB4 APL cells in a time-dependent manner. The relationship between PML-RARα degradation and apoptosis triggered by TPEN deserves further study.
      Graphical abstract image

      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.07.007
       
  • Heteroleptic oxidovanadium(IV) complexes of 2-hydroxynaphtylaldimine and
           polypyridyl ligands against Trypanosoma cruzi and prostate cancer cells
    • Authors: Gonzalo Scalese; M. Florencia Mosquillo; Santiago Rostán; Jorge Castiglioni; Irina Alho; Leticia Pérez; Isabel Correia; Fernanda Marques; João Costa Pessoa; Dinorah Gambino
      Abstract: Publication date: Available online 18 July 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Gonzalo Scalese, M. Florencia Mosquillo, Santiago Rostán, Jorge Castiglioni, Irina Alho, Leticia Pérez, Isabel Correia, Fernanda Marques, João Costa Pessoa, Dinorah Gambino
      In Latin America Chagas disease is an endemic illness caused by the parasite Trypanosoma cruzi, killing more people than any other parasitic disease. Current chemotherapies are old and inadequate, thus the development of efficient ones is urgently needed. Vanadium-based complexes have been shown to be a promising approach both against parasitic diseases and cancer and this study aims to achieve significant advances in the pursue of effective compounds. Heteroleptic vanadium complexes of Schiff bases and polypyridine compounds were prepared and their stability in solution evaluated by EPR and NMR spectroscopy. Their in vitro activities were evaluated against T. cruzi and a set of cells lines representative of human cancer conditions, namely ovarian, breast and prostate cancer. In T. cruzi, most of the complexes depicted IC50 values in the low μM range, induced changes of mitochondrial membrane potential and apoptosis. In cancer cells, complexes showed good to moderate activity and in metastatic cells (prostate PC3), some complexes inhibited the migratory ability, this suggesting that they display antimetastatic potential. Interestingly, complex 5 seemed to have a dual effect being the most cytotoxic complex on all cancer cells and also the most active anti-T-cruzi compound of the series. Globally the complexes showed promising anticancer and anti T. cruzi activities and also displayed some characteristics indicating they are worth to be further explored as antimetastatic drugs.
      Graphical abstract image

      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.07.014
       
  • Heteroleptic monometallic and trimetallic ruthenium(II) complexes
           incorporating a π-extended dipyrrin ligand: Light-activated reactions
           with the A549 lung cancer cell line
    • Authors: Shawn Swavey; Krista Morford; Max Tsao; Kristen Comfort; Mary Kate Kilroy
      Abstract: Publication date: Available online 18 July 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Shawn Swavey, Krista Morford, Max Tsao, Kristen Comfort, Mary Kate Kilroy
      A heteroleptic monometallic ruthenium(II) and a heteroleptic trimetallic ruthenium(II) complex have been synthesized and characterized. Both complexes have an overall 3+ charge, with the charge density greater for the monometallic complex. The electronic spectra of the monometallic ruthenium(II) complex exhibits intense π-π* transitions associated with the bipyridyl groups along with overlapping metal to ligand charge transfer (MLCT) and ligand centered π-π* transitions ranging from 520nm to approximately 600nm. The trimetallic ruthenium(II) complex, on the other hand, displays more well defined transitions with the expected π-π* transition of the bipyridyl groups at 294nm and Ru(dπ) to bpy(π*) MLCT transitions at 355nm and 502nm. In addition to these absorption bands an intense transition, 578nm, resulting from overlapping dipyrrin (π-π*) and Ru(dπ) to dipyrrin(π*) transitions is observed. Electrochemical and spectroelectrochemical experiments were used to help in assigning these transitions. Irradiation of the complexes in the presence of plasmid DNA within the photodynamic therapy window (600nm to 850nm) reveal, using electrophoresis, that both complexes are capable of causing photo-damage to the DNA backbone. The trimetallic ruthenium(II) complex; however, also shows the ability to generate photoinduced DNA damage in the absence of oxygen, suggesting a photo-oxidative process. Studies of the complexes toward lung cancer cells (A549 cell line) in the absence of light indicate little cytotoxicity up to 50μM. Upon irradiation of the cells with a low power 420nm light source the trimetallic complex showed considerably greater photo-cytotoxicity compared to the monometallic analog. A dose-dependent response curve gives an IC50 of 92μM for complex B.
      Graphical abstract image

      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.07.012
       
  • Effect of tunable redox behavior of bis chelate substituted
           1,10-phenantroline Cu(II) complexes on its reaction with superoxide anion
           in DMSO. Toward a simple criterion to identify a SOD-like mechanism
    • Authors: Mayra E. Manzanera-Estrada; Marisela Cruz-Ramírez; Marcos Flores-Alamo; José Miguel Gracia y Jiménez; Rodrigo Galindo-Murillo; Juan Carlos García-Ramos; Lena Ruiz-Azuara; Luis Ortiz-Frade
      Abstract: Publication date: Available online 18 July 2017
      Source:Journal of Inorganic Biochemistry
      Author(s): Mayra E. Manzanera-Estrada, Marisela Cruz-Ramírez, Marcos Flores-Alamo, José Miguel Gracia y Jiménez, Rodrigo Galindo-Murillo, Juan Carlos García-Ramos, Lena Ruiz-Azuara, Luis Ortiz-Frade
      In this work we report a series of Cu(II) complexes [Cu(NN)2(X)]+, (NN=substituted 1,10-phenanthroline derivatives and X=Cl− or NO3 −), with tunable E1/2 for electrochemical reduction [CuII(NN)2(X)]+ +1e− ⇌[CuI(NN)2]+X−. The disproportion of O2 •− Cu(II)+1e→Cu(I) was explored in presence of the electro-generated species [CuI(NN)2]+ using cyclic voltammetry in a non-aqueous media, arising a new simple method to propose a SOD-like mechanism, which can be used as a quick guide test for a compound, before being proven in biological assays. It was found that complexes with high negative half wave potential values (E1/2) for Cu(II)/Cu(I) couple shown an increment of current for oxygen reduction, related to the capability of the disproportion of this reactive oxygen species.
      Graphical abstract image

      PubDate: 2017-07-20T17:35:45Z
      DOI: 10.1016/j.jinorgbio.2017.07.013
       
 
 
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