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J. of Analytic Divinity     Open Access  
J. of the Turkish Chemical Society, Section A : Chemistry     Open Access  
Turkish J. of Forecasting     Open Access   (Followers: 1)
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Journal of the Turkish Chemical Society, Section A : Chemistry
Number of Followers: 0  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2149-0120
Published by DePauw University Homepage  [3 journals]
  • Production of Rosmarinic Acid Nanoparticles, and Investigation of
           Anti-Oxidation Effects on Salmon Fish Meat

    • Authors: Zafer CEYLAN; Yasemin BUDAMA KİLİNC, Azime YILMAZ, Kübra ÜNAL, Burak ÖZDENİR
      Abstract: In this study, an anti-oxidant nanoformulation to prevent the oxidation of salmon was developed using rosmarinic acid (RA). Minced salmon samples (MSs) were treated with 8.10-3 g (RAT1) and 16.10-3 g (RAT2) RA-loaded nanoparticles for 100 g MS rosmarinic acid, separately. The thiobarbituric acid (TBA) values of control (C), RAT1, and RAT2 samples stored at 4 °C were found as 2.995, 1.350, and 0.994 mg MDA/kg; respectively, after 9 days. While the initial free fatty acid (FFA) value of C samples was 2.011%, RAT1 and RAT2 were found as 2.765% and 2.494%, respectively. The 2,2,diphenylpicrylhydrazyl (DPPH) values of MSs treated with RAT1 and RAT2 were observed to be higher than that of C samples. C samples were evaluated as unfit for human consumption on the 5th day of the storage, it was revealed that but the sensory scores of MSs treated with RAT1 and RAT2 were still acceptable for human consumption.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Recent Studies on Antioxidant, Antimicrobial, and Ethnobotanical Uses of
           Hypericum perforatum L. (Hypericaceae)

    • Authors: Emre YILMAZOĞLU; Metin HASDEMİR, Belma HASDEMİR
      Abstract: Hypericum perforatum L. (Hypericaceae) is one of the medicinal plants whose value has increased rapidly in recent years. It is especially popular for its use in the treatment of mild and moderate depression, as well as for the treatment of skin diseases, internal and external inflammatory wounds, neurological disorders, and the metabolism-disrupting effects of free radicals. Besides, it shows inhibitory effects against different kinds of microorganisms such as bacteria, fungus, and protozoa. Antimicrobial biofilms generated by the plant are its most potent output, unlike its essential oil which does not have much value in itself as much as its ingredients that can be converted into more valuable products. Its usage as a folk remedy has a wide application area in various cultures. It is thought that compiling studies on various aspects of this plant will benefit future studies. The present paper reports on studies on the antibacterial, antioxidant, and therapeutic properties of Hypericum perforatum, as well as on the composition of its essential oil.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Development of Functional Guar Gum-Based Highly Water Absorbent and
           Investigation of Reaction Parameters

    • Authors: Sapna ; Jay SİNGH, Arpit SAND
      Abstract: The present article describes guar-gum (GG) polysaccharide-based eco-friendly highly water absorbable polymer network with itaconic acid (IA) and acrylamide (AAm) as monomers, prepared due to characteristic features such as natural abundance, biocompatibilities, and biodegradability as well as biological and physicochemical properties. The solution polymerization technique was used successfully to synthesize the GG-g-PIA-co-AAm co-polymer. In this method, IA and AAm monomer polymerize onto polysaccharides GG in an aqueous medium at 70 °C with potassium persulfate (KPS) acting as a chemical initiator and N, N′-methylene-bisacrylamide (N-MBA) acting as a cross-linker. The maximum allowed time to complete the reaction was 1 hour and 20 minutes. The consequence of the neutralization degree of itaconic acid, GG, AAm, N-MBA, and KPS was optimized. Surface morphology and binding behavior of prepared GG-g-PIA-co-AAm were characterized by FTIR and SEM microscopy. The grafting (between GG and IA and AAm and crosslinking reactions were produced by a solid chemical empathy between the NH2 groups in the guar gum and the carboxylic groups in the poly itaconic acid, leading to the formation of amide bonds. Various parameters like free-absorbency capacity (FAC) as high as possible and (AUL) were also studied for efficient absorbent polymers. A hypothetical mechanism for polymeric reaction during polymerization has been proposed.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Biogas Production from Wheat Straw using Textile Industrial Wastewater by
           Co-digestion Process: Experimental and Kinetic Study

    • Authors: Punam RANİ; Megha BANSAL, Vinayak Vandan PATHAK
      Abstract: In the present experimental study, anaerobic co-digestion of wheat straw with textile industry wastewater (TIWW) was evaluated for biogas production. Anaerobic digestion systems were operated at ambient temperature (28-30 ºC) for 20 days. Five different ratios of wastewater with distilled water were added to wheat straw inoculated with cow dung operating in five digesters. Time-rate derivative models, including Gompertz’s model and its related extensions, were used to represent yields. It has been found that the slurry containing wheat straw and cow dung digested with 75% diluted wastewater has the maximum production, while the slurry digested with only wastewater (not diluted with distilled water) has minimum production.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Stability Indicating RP-HPLC Method Development and Validation for
           Bosentan in Pharmaceutical Formulations

    • Authors: Mehmet Emrah YAMAN; Alptuğ ATİLA, Yücel KADIOĞLU
      Abstract: The development and validation of a novel, simple, and quick HPLC technique for measuring bosentan in pharmaceutical formulations was performed. The technique parameters were tuned to be 1 mL/min flow rate, variable column temperature, and a mobile phase combination of methanol-acetonitrile-water (20:50:30 v/v/v) to carry out this study. All measurements were carried out with a UV detector at a wavelength of 272 nm. Specificity, the limit of quantitation (LOQ), limit of detection (LOD), linearity, accuracy, precision, stability, recovery, and ruggedness were all tested. The technique was linear between 0.25 and 20 µg/mL, with precision (RSD%) and accuracy (RE%) of less than 3.0 and 2.7%, respectively. The LOQ and LOD values of method were 0.25 and 0.1 µg/mL, respectively. The 10 µg/mL of standard bosentan solution was found to be moderately stable in acidic and basic settings (0.1 M HCl and 0.1 M NaOH) but unstable in an oxidative environment (H2O2 solution; 3%). No interference from tablet excipients was observed in the HPLC method. The approach was successfully applied to pharmaceutical formulations obtained from a local pharmacy store.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Ethnobotany, Phytochemistry, Ethnopharmacology, and Toxicity of Euclea
           divinorum Hern (Ebenaceae): A Review

    • Authors: Timothy OMARA; Benard Otieno SADİA, Immaculate MBABAZİ, Augastine OKWİR
      Abstract: Euclea divinorum Hiern (Ebenaceae) is a medicinal plant widely used in Yemen, Eastern and Southern Africa in traditional phytotherapy. This review was an attempt to compile a comprehensive report on its ethnomedicinal uses, phytochemicals, pharmacological activities, and toxicity, lending credence to the use of its various parts in herbal medicine. The literature encountered indicated that herbal formularies from different parts of Euclea divinorum (E. divinorum) are majorly used for traditional treatment of odontological, dermatological, respiratory, reproductive, and gastrointestinal ailments. At least 18 compounds have been isolated and characterized in extracts of E. divinorum, while 31 others have been identified in the crude extracts analyzed by GC-MS. Extracts, as well as isolated compounds from E. divinorum stem, stem barks, leaves, and roots, showed renoprotective, antiproliferative, antinociceptive, contractile, proteolytic, diuretic, antiprotozoal, anti-giardial, antioxidant, anti-inflammatory, antimicrobial, molluscicidal, and insecticidal activities. Further research is warranted to explore other pharmacological properties such as antisnake venom, aphrodisiac, antidiabetic, analgesic, and antimycobacterial activities and the responsible bioactive compounds in the different parts of E. divinorum claimed in herbal medicine. The composition and bioactivities of essential oils from this species also warrant further studies.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • A Simple Spectrophotometric Determination of Amoxicillin in Drug Samples

    • Authors: Adem ASAN; Nada SEDDIQ
      Abstract: In this study, a fast and simple spectrophotometric method was developed for the determination of amoxicillin in drugs without any extraction steps. The developed method is based on the formation of a colored ion pair complex between bromocresol green and amoxycillin in dimethyl sulfoxide-acetonitrile (50 % v/v) medium. The absorbance of the bluish green complex is measured at a wavelength of 630 nm. The factors that affect the ion pair complex formation, such as time, reagent concentration, etc., have been optimized. Under the optimum conditions, the developed method had an average recovery of 98.16% with a relative standard deviation of 3.62 % and showed a very good linear behavior obeying Lambert-Beer's law in the range 1-18 µg mL-1 of amoxycillin concentration. The developed method has been successfully applied to both tablet and powder forms of pharmaceutical preparations. The standard addition method and statistical parameters were applied to test the accuracy of the proposed method, and the obtained results from the two methods showed good agreement with each other.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Determination of Heavy Metals in Tobacco Leaves and Their Growing Soils in
           Assosa District, Benshangul Gumuz Regional State, Ethiopia

    • Authors: Tsegaye MELKAMU; Abera GURE, Tsegaye Girma ASERE
      Abstract: Tobacco is a commercial plant that can accumulate heavy metals in its leaves. In this study, we investigated the levels of selected heavy metals (Mn, Cu, Zn, Cd, and Pb) in tobacco leaves and their growing soils from Assosa District, Benshangul Gumuz Regional State, Ethiopia. Both samples were collected from five tobacco farmlands. The samples were digested before quantitative determinations of the metals via inductively coupled plasma optical emission spectroscopy (ICP-OES). Repeatability and recovery studies were used to evaluate the efficiency of the method. Repeatability was evaluated by analyzing replicate samples and expressed as relative standard deviations (RSD) were below 10.0. Recovery or percent recovery (%R) studies, which were performed by spiking known concentrations of metals into the samples, ranged from 85.67 - 111.33% and 84.25 - 114.00% for tobacco leaves and soil samples, respectively, indicating that the employed method is valid for the analysis of the metals. The concentrations of metals in tobacco leaf samples were: 0.75 -1.18 mg/kg, Mn; 0.11-0.21 mg/kg, Cu; 0.58-1.16 mg/kg, Zn; and not quantified (NQ) - 0.01 mg/kg, Cd. In soil samples, their concentrations were: 1.59-8.04 mg/kg, Mn; 0.32 - 0.38 mg/kg, Cu; and 0.29 - 1.26 mg/kg, Zn; and 0.17 - 0.31 mg/kg, Pb. Except in one tobacco leaf sample, Pb was below the limit of quantification (LOQ). Similarly, in all soil samples, the concentration of Cd was below LOQ. The findings indicate that the concentrations of the studied heavy metals in both tobacco leaves and soil samples are below their WHO permissible limits in soil and plants. However, the levels of Zn in Amba and Basha tobacco leaves were higher than the WHO permissible limit in plants.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Ricinus Communis Seed oils as a Source of Biodiesel; A Renewable Form of
           Future Energy

    • Authors: Hadush GEBREHİWOT; Demis ZELELEW
      Abstract: Diminishing supply and environmental pollution of fossil fuels are the vital factors leading to the search of alternative sources of energy like biodiesel. Biodiesel is one of the eco-friendly substitutes of energy which is mainly utilized in diesel engines. Ricinus communis (castor plant), which belongs to the family Euphorbiaceae yields an oil rich beans and plays important role in the production of biodiesel. Recently, the demand of castor oil and its products has been raised in the world market due to its versatility to use and simplicity to produce. Therefore, this study investigates the extraction of castor oil and its conversion in to biodiesel via alkali catalyzed transesterification. The seed oil of the plant was extracted using Soxhlet apparatus and the quality of the biodiesel was examined using the standard procedures of American standards for testing methods. Furthermore, the chemical composition of the extracted oil was examined using GC-MS. The seed oil was liquid at room temperature (25 °C), golden yellow in color with a nutty odor. The extraction processes yielded 324 g (9.25% w/w) and 78% of oil and biodiesel respectively. The density (0.86 g/mL), viscosity (5.42 mm2s-1), flash point (87 °C), acid value (0.35 mg KOH/g), water content (0.80%), iodine value (108.60), and cetane number (58.00) were reported in this study and showed a good agreement with the standards of biodiesel. GC-MS analysis of the seed oil also showed the presence of 10 different fatty acids (9-Octadecenoic acid, 12-hydroxy-, methyl ester, [R-(Z)] took the highest composition) which plays significant role for the production of methyl esters. So, the study can assure that castor oil can be used for commercial production of biodiesel at cost effective scales.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Exploration of Role of Concentration on Sensing Activities using Novel
           unsymmetrical Schiff bases

    • Authors: Saranya DHASARATHAN; Selvaraj SHUNMUGAPERUMAL, Kamatchi SELVARAJ P
      Abstract: Simultaneous condensation reaction of thiocarbohydrazide with simple aromatic aldehyde and highly reactive ferrocenecarboxaldehyde resulted with unusual unsymmentric Schiff bases associated with multi metal ion sensing property. Spectral characterization methods indicate the formation of the new materials. Guest- host relationship established between various metal ions and receptors changes the electronic spectra drastically and for the addition of Cu2+ ions, formation of MLCT charge transfer band responsible for the coordination of metal ion with receptor has been noticed. Data calculated from the results of responses recorded for the applied potential to the metal added and metal free receptor solution exposes the concentration of metal ions required for the effective sensing process.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Accuracy Limits of Pair Distribution Function Analysis in Structural
           Characterization of Nanocrystalline Powders by X-ray Diffraction

    • Authors: Abolfazl BALOOCHİYAN; Merdan BATYROV, Hande OZTURK
      Abstract: We report the minimum errors of structural parameters, namely lattice parameter, crystallite size, and atomic displacement parameters, expected from Pair Distribution Function (PDF) analysis of nanocrystalline gold powders for the first time by a self-consistent computational methodology. Although PDF analysis has been increasingly used to characterize nanocrystalline powders by X-rays, the current literature includes no established error bounds to be expected from the resulting structural parameters. For accurate interpretation of X-ray diffraction data, these error bounds must be determined, and the obtained structural parameters must be cleared from them. Our novel methodology includes: 1) simulation of ideal powder diffraction experiments with the use of the Debye scattering equation, 2) pair distribution function analysis of the diffraction data with the Diffpy-CMI analysis software, and 3) determination of the errors from PDF analysis of the simulated diffraction data by comparing them with real-space analysis of spherical gold nanocrystals that are 30 nm size and smaller. Our results show that except for the lattice parameters and even with an ideal crystalline powder sample and ideal diffraction data, the extracted structural parameters from PDF analysis diverge from their true values for the studied nanopowder. These deviations are dependent on the average size of the nanocrystals and the energy of the X-rays selected for the diffraction experiments, where lower X-ray energies and small-sized nanocrystalline powders lead to greater errors.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Waste Polyurethane Reinforced Polyester Composite, Production, and
           Characterization

    • Authors: Maruf Hurşit DEMİREL; Ercan AYDOĞMUŞ
      Abstract: In this research, new composite materials were improved by reinforcing the environment-polluting waste polyurethane (WPU) to unsaturated polyester (UP). Polyester composites were produced with WPU, UP, methyl ethyl ketone peroxide (MEKP), and cobalt octoate (Co. Oc.). The effect of WPU on the changes in density, Shore D hardness, thermal conductivity coefficient, thermal stability, and porosity of the obtained composites were investigated. According to the findings, as WPU ratio increased in the composite, both the thermal conductivity coefficient and the density of the composite decreased. Shore D hardness was been found to decrease as the rate of WPU in polyester composites raised. The use of optimum WPU ratios (7 wt.%) in composite production improved some thermo-physical properties of polyester composite. The high use of WPU negatively affected both the surface morphology and thermal stability of the polyester composite. In addition, the parameters affecting the production of polyester composites were optimized according to response surface methodology (RSM).
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Chemical constituents of the stem bark of Prunus africana and Evaluation
           of their Antibacterial Activity

    • Authors: Desalegn Abebe DERESA; Zelalem ABDİSSA, Getahun Tadesse GURMESSA, Negera ABDİSSA
      Abstract: Chromatographic separation of the methanolic extract of Prunus africana stem bark led to the isolation of five compounds (β- sitosterol (1), benzoic acid (2), two oleanolic derivatives (3 and 4), and p-hydroxybenzoic acid (5). The structures of compounds were elucidated based on 1D and 2D NMR spectral data and compared with reported literature values. This is the first report of benzoic acid and its derivatives from the genus Prunus. The crude extract and isolated compounds were evaluated for their antibacterial activity against five bacterial strains (E. coli, S. aureus, S. flexineri, S.typhimurium, and P. aeruginosa) using disc diffusion assay and showed good antibacterial activity against the tested strains. The crude extract showed potent activity (21.03 + 0.05 mm) against P. aeruginosa, which is even greater than the reference drug gentamycin (14.06 + 0.09 mm). The antibacterial activity of P.africana extract and isolated compounds supports its traditional use, suggesting that it could be considered as a source of bioactive compounds in antimicrobial drug development.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Extraction, Optimization, and Characterization of Neem Seed Oil via
           Box-Behnken Design Approach

    • Authors: Ketema BEYECHA HUNDİE; Desalegn ABDİSSA, Abreham BEKELE BAYU
      Abstract: This study was aimed at extracting, optimizing, and characterizing the neem seed oil through Box-Behnken design. The effects of extraction parameters such as temperature (50-80°C), particle size (0.15–0.3 mm), and time (60-180 min) were considered. The extraction of oil was studied using the soxhlet extraction process, applying n-hexane as a solvent. The quadratic model was suggested to demonstrate optimal extraction parameters of 132.677 min, 64.416°C of temperature, and 0.212 mm of particle size using numerical optimization. The experimental yield of oil at optimum conditions 44.141%, which was close to the model-anticipated value. The physicochemical properties suggested that neem oil had an ash content of 2.1%, moisture content 4.61%, density 0.875 g/cm3, viscosity 33.5 mm2/s, specific gravity 0.88, saponification value 206.7 mg KOH/, iodine value 122.5 g I2/100 g, acid value 1.81 mg KOH/g, and cetane number of 75. The extraction parameters had a significant effect on the yield of neem seed oil. However, the temperature and particle size had a higher effect compared to the extraction time. The most important unsaturated fatty acid is oleic acid (60.924 %). The properties of the oil revealed that the neem seed oil can be used as a potential source of material for industrial applications. It can be concluded that neem seeds have the potential to be used as industrial feedstocks in the future.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Studies on Graft Copolymerization Of Acrylic Acid Onto Acetylated
           Cellulose From Maize Cob

    • Authors: Aliyu MOHAMMED
      Abstract: Acrylic acid was grafted onto cellulose acetate using ceric ammonium nitrate (CAN) initiator at varying temperature (30, 40, 50, 60, 70, 80 ˚C) and reaction period of 2-6 hours. Grafting parameters like grafting yield (GY), grafting efficiency (GE) and total conversion of monomer to polymer (TC) were evaluated at different reaction conditions such as temperature, time, monomer and initiator concentration. The homopolymer was removed from the reaction mixture using Soxhlet extraction. The graft copolymer of cellulose acetate produced at 70 °C after 3 hours had the highest GY of 85%. The products were characterized by Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Algerian Bunium incrassatum Seeds: Effects of Extraction Solvent Polarity
           on Phenolic Profile and Antioxidant Activity

    • Authors: Fethi TOUL; Amina DJENDAR, Meryem SELADJİ, Farid BERROUKECHE
      Abstract: Bunium incrassatum, vernacularly called ‘Talghouda’ is one of the most important plant species of the traditional Algerian pharmacopeia, used for medicinal and culinary purposes. Despite of its benefits, it still remains a scientifically neglected species, especially with regards to the phytochemical profile. The present study aims to evaluate the antioxidant potentials of Bunium incrassatum seeds’ extracts prepared in different solvents with increasing polarities.The antioxidant potentials of extracts were measured using DPPH and β-carotene Bleaching assays. Total phenolic, flavonoid, and tannin contents were also spectrophotometrically determined. The phenolic profiles were screened through RP-HPLC.Methanol extract showed the highest DPPH scavenging potential and also the highest inhibitory potential against β-carotene bleaching (IC50=0.15±0.02 and 0.41±0.03 mg/mL, respectively). Thirteen phenolic compounds were identified, a flavanol (catechin), two flavonols (kaempferol, quercetin), two flavanones (hesperetin, naringenin) and eight phenolic acids: caffeic acid, chlorogenic acid, ellagic acid, ferulic acid, gallic acid, p-coumaric acid, sinapic acid, and syringic acid.These results support the few previous studies showing that Bunium incrassatum, as an endemic species, is considered as a good source of bioactive compounds that requires further investigations.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Optoelectronic Parameters of 2-oxo-2-(1-oxo-1H-isochromen-3-yl)ethyl
           methacrylate Compound Thin Film

    • Authors: Adnan KURT; Murat KOCA
      Abstract: The UV/VIS spectrophotometric scans were obtained to determine the opto-electronic properties of 2-oxo-2-(1-oxo-1H-isochromen-3-yl)ethyl methacrylate (other name: 2-(isocoumarin-3-yl)-2-oxoethyl methacrylate) compound thin film. The refractive index of compound at 700 nm was found to be 1.61. The values of the real part of the dielectric constant were higher than those of the imaginary part. The results indicated that the electronic transition responsible for the absorption was the indirect allowed one. The optical band gap constant and the Urbach energy corresponding to the width of the band tails of localized states were calculated to be 3.19 eV and 1.05 eV, respectively. From the results obtained, it is predicted that 2-oxo-2-(1-oxo-1H-isochromen-3-yl)ethyl methacrylate (OICEMA) compound can take place in the semiconductor class and play a role in the design of some electro-optic materials.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Microwave-assisted extraction of Prunus cerasus L. peels: Citric
           acid-based deep eutectic solvents

    • Authors: Ebru KURTULBAŞ ŞAHİN
      Abstract: In the present study, waste by-products of one of the popular fruit juices in the World has been valorized for its high-added value ingredients. Peels of sour cherry (Prunus cerasus L.) have been extracted by means of deep eutectic solvent (DES)-based microwave-assisted extraction (MAE). DES system contained citric acid as hydrogen bond acceptor (HBA) and ethylene glycol as hydrogen bond donor (HBD) (1/4, molar ratio). In order to optimize the MAE system Central Composite design (CCD) of Response Surface Method (RSM) has been used. The measured variables were the yields of total phenolic (TPC), total anthocyanins (TA) and cyanidin-3-glucoside. Optimum conditions were determined as 0.1 g of peel and 50 % (v/v) water contribution to the DES for the maximum reovery of TPC (16.85 mg-GAE/g-FP), TA (3.39 mg-cyn-3-glu/g-FP) and cyanidin-3-glucoside (mg/g-FP) in the MAE of sour cherry peels. The relationship between the responses was also established.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Exposure Analysis at the territory of Nev┼čehir (Cappadocia) due to
           additive gamma-rays in air, TURKEY

    • Authors: Muttalip Ergun TURGAY; Merve CİCEKFİDAN, Nursel SEZGİN
      Abstract: Radioactivity measurements for water, soil, and air have been completed in national and international regions. The radioactivity process is randomized and occurs naturally by primordial nuclides. Another case is hand-made reactions which realized by artificial reactions. The high rate of the total dose of radiation, whichever is exposed to humans, originates as Natural Radioactivity. In this case, environmental radioactivity measurements are important to investigate the background radiation level, especially for primordial radioactive sources. This radiation which measured outdoor gamma dose includes both cosmic rays and terrestrial elements. Terrestrial radiation can be measured via gamma-ray spectroscopy separately. By the way, cosmic effects would be calculated by subtracting terrestrial from measured outdoor gamma dose. Scientific Committee (UNSCEAR, 2000) declares the annual dose for humans as 2.4 mSv. The radionuclides present in soil samples (terrestrial components) are considered responsible for a portion of this amount (1). Rest amounts are originated water (2) and air, too.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Novel Functional Axially Substituted Silicon (IV) Phthalocyanine
           Derivative and its Photochemical Properties

    • Authors: Hülya YANIK; Gülçin EKİNEKER
      Abstract: Photodynamic therapy is a highly specific and clinically approved method in which a non-toxic photosensitizer drug is administered to the patient for cancer treatment. Phthalocyanines with their long wavelength absorption and fluorescence from 650 to 800 nm can be used as photosensitizers for photodynamic therapy and are used in clinical trials. In this study, functional novel axially substituted silicon (IV) phthalocyanine (PS-2) was synthesized. Unsubstituted dichlorosilicon (IV) phthalocyanine was synthesized from 1,3-diiminoisoindoline via cyclotetramerization. The axial substitution reaction was carried out using dichlorosilicon (IV) phthalocyanine and excess of N-Boc-ethanolamine. Structural characterization of this novel PS-2 by FT-IR, mass, 1H NMR and UV-Vis spectroscopy were performed. Photochemical properties (photo degradation quantum yields (d) and singlet oxygen quantum yield () of PS-2, which are the first steps for cancer treatment, were investigated.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Cyclization Reactions of Non-Conjugate Ynones with Propargyl Amine in the
           Presence of a Catalyst

    • Authors: Volkan TAŞDEMİR
      Abstract: In this study, acetate derivatives were obtained from the reaction of acetophenones using diethyl carbonate. The acidic proton of CH2 moiety was abstracted using a suitable base and α-propargyl-β-ketoester (non-conjugated ynone) derivatives 3a-c were obtained from the reaction of the acetate derivatives with propargyl bromide. By removing the ester group of α propargyl-β-ketoester derivatives under suitable conditions, α-propargyl acetophenones (non-conjugated ynone) 4a-c were obtained. In this study, 6 different unconjugated ynone derivatives were synthesized as starting material with yield in a range of 60-95%. Cyclization reactions with propargyl amine in the presence of three different unconjugated ynone derivatives, metal catalysts were investigated. The synthesis of propargyl pyrroles 7a-c having substituents on C-2 and C-5 was completed.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Adsorption Studies of Radionuclides by Turkish Minerals: A Review

    • Authors: Süleyman İNAN; Ümran HİÇSÖNMEZ
      Abstract: Hazardous radionuclides are produced during normal operation of nuclear power plants and research facilities. They can also spread to the environment due to fallout from nuclear accidents and nuclear weapon tests. The removal of hazardous radionuclides and the safe management of radioactive waste are of vital necessity. Natural minerals have been widely used for the removal of heavy metals and radionuclides because of their low cost, high capacity and radiation resistance properties. Turkey has an abundant natural mineral deposits. These deposits include clinoptilolite, bentonite, montmorillonite, kaolinite, vermiculite, illite, red clay, sepiolite, diatomite, perlite and volcanic tuff. Within the scope of this review, Turkish minerals were classified as three main groups as; zeolites, clay minerals and other minerals. The review consists of sections on the general properties of natural minerals such as zeolites and clays, the characteristics of Turkish minerals, and the adsorption performance of these minerals against some radionuclide ions (Sr, Cs, U, Th and Po).
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Enhancement of the O2 Sensitivity: ZnO, CuO, and ZnO/CuO Hybrid
           Additives' Effect on Meso-Tetraphenylporphyrin Dye

    • Authors: Merve ZEYREK ONGUN
      Abstract: Semiconductor metal oxide materials have attracted great interest in gas sensors due to their high sensitivity to many target gases. In this study, an oxygen-sensitive optical chemical sensor was prepared in thin-film form by immobilizing meso-tetraphenylporphyrin (H2TPP) in silicon matrix in the presence of ZnO, CuO and ZnO/CuO hybrid nanoparticles as additives. Characterization of synthesized metal oxide powders was performed using XPS, XRD, SEM, and PL spectroscopy. Emission and decay time measurements of H2TPP-based materials were investigated between the concentration range of 0% and 100% [O2] in thin-film forms. The intensity-based signal drops of the additive-free form of porphyrin dye toward oxygen were calculated as 70%. Whereas, the oxygen sensitivities of H2TPP-based sensor slides were measured as 80%, 75%, and 88% in the presence of ZnO, CuO, and ZnO/CuO hybrid particles, respectively. The usage of porphyrin dye with ZnO/CuO hybrid additive provided higher oxygen sensitivity, larger linear response range, higher Stern-Volmer constant (KSV) value and faster response time compared to the undoped form, ZnO and CuO additive-doped forms of H2TPP. The response and the recovery times of the porphyrin-based sensing slide along with ZnO/CuO hybrid particles have been measured as 10 and 20 s. These results make the H2TPP along with the metal oxide additives promising candidates as oxygen probes.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Enrichment of Magnesite and Usage to Obtain Magnesium Fluoride

    • Authors: Çiğdem ARAS; Birsen DEMİRATA, Kevser SÖZGEN BAŞKAN
      Abstract: Magnesium is the sixth most abundant element, constituting 2% of the total mass of the earth's crust. It is a metal that exists only in chemical compounds, and generally exits in carbonate and oxide forms. The most important mineral forms are magnesite (MgCO3), dolomite (MgCO3.CaCO3) and carnallite (KCl.MgCl2-6H2O). Magnesium metal, which is obtained from different sources by various methods, has an important place in the industry. There are approximately 16 billion tons of dolomite and 110 million tons of magnesite reserves in Turkey. The aim of this study is to investigate the use of idle magnesium clay raw material (in Eskişehir) for the production of magnesium fluoride and thus to propose a chemical process for the relevant raw material to the industry. For the experiments, a 10 kg sample was taken and after the whole was ground to 75 µm size, XRF, XRD and DTA analyzes were performed. As a result of XRF analysis, it was determined that it contains 44.28% MgO. As a result of XRD analysis, it was determined that it is magnesite with MgCO3 structure, and also it has dolomite and chlorite group mineral structures. As a result of the experiments, MgF2 was obtained by using HF from the relevant raw material, and it was determined that the efficiency was higher in the experiments performed with raw magnesite.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
  • Angiotensin(1-7)-Stearic Acid Conjugate: Synthesis and Characterization

    • Authors: Tayfun ACAR; Burcu UÇAR
      Abstract: The novel coronavirus, SARS-CoV-2, broken out as the COVID-19 epidemic, is transported into the cytoplasm by angiotensin-converting enzyme-2 (ACE2), a key protein of the renin-angiotensin-system (RAS). ACE2 is a protective protein that reduces angiotensin (Ang) II, the bioactive component of RAS, by converting it to its potent antagonist, Ang-(1-7) peptide, in order to provide a pathophysiological response to stimuli. Although ACE-2 is upregulated especially in pulmonary endothelial cells and alveolar epithelial cells, downregulation of ACE-2 in the lung owing to loss of key regulatory factors explains the enzyme-dependent lethality of SARS-CoV-2. The N-terminal domain (NTD) of S1, one of the protein subunits of coronaviruses, is known to recognize acetylated sialic acids on glycosylated cell surface receptors. In this study, the stearic acid-peptide conjugate mimicking the sialic acid structure was synthesized, which will be able to balance uncontrolled inflammatory response and excessive cytokine production, and depending on these to suppress pneumonia and acute respiratory distress syndrome (ARDS), against SARS-CoV-2. It was expected that fatty acid acylation would greatly enhance cellular internalization and cytosolic distribution of the peptide through the cell membrane. Thus, we synthesized fatty acyl derivative of the N-Ac-Gly4-Ang (1-7) peptide. The peptide was synthesized using Fmoc/tBu solid-phase peptide chemistry and characterized by FT-IR, Zetasizer, and LC-ESI-MS. This study provided more detailed insights into understanding and meeting the basic structural requirements for optimal cellular delivery and formulation of the stearyl Ang (1-7)-peptide conjugate.
      PubDate: Tue, 31 May 2022 00:00:00 +030
       
 
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