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Advanced Journal of Chemistry, Section A
Number of Followers: 4

This is an Open Access Journal

Open Access journal
ISSN (Print) 2645-7768 - ISSN (Online) 2645-5676
Published by Sami Publishing Company

[3 journals]

Theoretical Investigations on Thiadiazole Derivatives as Corrosion
Inhibitors on Mild Steel
- Abstract: Experimental methods have been employed to elucidate the corrosion inhibition mechanism, but they are often expensive and time-consuming, necessitating the search for more alternatives. The development of computer hardware and software engineering has allowed the effective use of theoretical modeling tools that successfully correlate the inhibition efficiency of the inhibitors with their molecular structure and properties. In this study, computational methods were used to further explain the mode and mechanism of the thiadiazoles inhibition on Fe surface whose studies were reported in the literature as Thiadiazoles-A potential class of heterocyclic inhibitors for prevention of mild steel corrosion in hydrochloric acid solution. Parameters including quantum chemical through DFT and molecular dynamic simulations of studied molecules on Fe surfaces were performed. Results obtained by calculating these thiadiazoles' adsorption or binding energies were in good agreement with the experimentally reported results elsewhere. Concerning the calculated adsorption or binding energies, their relatively low values inferred that the compounds are weakly adsorbed onto the surface of Fe through Van der Waals forces and therefore obey the mechanism of physical adsorption. Fukui indices values revealed that the active sites were found to be located on the molecules heteroatoms (Sulphur and Nitrogen). It was also established that the reference molecule thiadiazole (TDA) was the least adsorbed when compared to the other four molecules of its derivatives. The order of the inhibition efficiency as determined is as follows: PAT > EAT > MAT > AT > TDA
Inhibitory Activity of Natural Flavonoids against Protein Aggregation in
Alzheimer's disease: A Computational Simulation Study
- Abstract: In this study, the prevention mechanism of chrysin, datiscetin, naringenin, and wogonin against Aβ peptide and tau protein aggregation was investigated using computational simulation methods. According to the molecular docking data, minor differences in the chemical structures of candidate compounds do not result in significant differences in docking binding energy. Instead, the ligand binding site and residue contact degree appear to have played a more significant role. Naringenin showed the highest affinity for tau protein due to its different binding site. Because of more residue contacts, chrysin and datiscetin also had a higher amyloid binding affinity. The secondary structure analysis of amyloid β revealed a significant loss of α-helix content in all systems studied with the formation of turns and random coils, which is most in the presence of wogonin. In all tau-ligand systems, the percentage of the coil decreased. In contrast, the turn percentage increased, indicating that the selected compounds can prevent the aggregation of AD-related receptors.
Effect of Nanoparticles on the Degradation, Ageing and other Properties of
Ester-based Nanofluids
- Abstract: Vegetable-based natural esters serve the dual purpose of insulating and cooling electrical transformers as a natural alternative to conventional mineral oils. The factory-functionalized SiO2 nanoparticles were dispersed into purified cotton seed oil methyl ester to produce a nanofluid with excellent electrical and thermal properties. A dispersion method was used to prepare the nanofluids with 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, and 0.8 wt. % nanoparticles into the ester at 0.1 wt. % increments. Scanning electron microscopy (SEM) coupled with electron dispersive X-ray (EDX) analysis was performed on the nanoparticles to determine their morphology and elemental composition. This study compares the results of testing samples of mineral oil, ester, and SiO2-based nanofluids before and after aging to determine their water content, flash point, pour point, dynamic viscosity, density, dielectric loss, permittivity, and breakdown strength. The results showed that CNF5 (Ester + 0.5 wt. % SiO2) performs better even after the samples have aged, owing to the addition of 0.8 wt. % SiO2 nanoparticles. CNF5 outperformed the other samples of nanofluid in terms of both thermal and dielectric properties. For CNF5, it was observed that the breakdown voltage, flash point, dynamic viscosity, tan delta, pour point, and water content decreased after ageing. It was also found that the cottonseed oil-based nanofluid improved the electrical and thermal properties more than mineral oil as nanoparticles were added to the samples.
Theoretical Investigation and Design of Novel Anti-proliferative Agents
against Hepatocellular Carcinoma from Benzimidazole-Chalcone derivatives
- Abstract: Hepatocellular carcinoma is recognized as a major cause of cancer-related deaths worldwide and has been a healthcare burden globally. In the search for novel chemotherapeutic agents for treating this disease, a set of benzimidazole-chalcone derivatives with proven inhibitory activities against HepG2 cancer cell line were subjected to QSAR modeling. Structural optimization of the most active derivatives guided by the dominant descriptors in the validated model (R2 = 0.93, R2Adj = 0.92, Q2LOO = 0.91, R2Pred = 0.81) led to the design of more potent analogs; H-1, H-2, and H-3, with predicted IC50 values of 26.07µM, 43.38µM, and 178.69 µM, respectively. Molecular docking simulations of these novel ligands against the active sites of epidermal growth factor receptor (EGFR) protein target recorded binding energy values of -8.4, -8.9, and -8.1 for H-1, H-2, and H-3, respectively. These values are better compared to -7.6 kcal/mol recorded for Doxorubicin, a standard drug for managing liver cancer used herein for quality assurance. Also, ADMET evaluation of the designed drug candidates reveals that they possess excellent pharmacokinetic and toxicity profiles. It is envisaged that the wealth of information obtainable from this work could help to discover and develop novel chemotherapeutic agents for treating systemic and early-stage hepatocellular carcinoma.
Quinazoline Derivatives as Corrosion Inhibitors on Aluminium Metal
Surface: A Theoretical Study
- Abstract: Quantum chemical calculations and molecular dynamics simulation techniques were used to assess the corrosion inhibition potential of the compound qiunazoline (QZN) and two of its derivatives, 6-chloro-4-imino-3-phenyl-3,4-dihydro-1H qiunazoline-2-thione (QZT) and 6-chloro-4-imino-3-phenyl-3,4-dihydro-1H qiunazoline-2-one (QZO). The values of the quantum chemical parameters EHOMO, ELUMO, energy gap (∆E), the energy of back donation (∆Eb-d), dipole moment (μ), electronegativity (χ), global hardness (η), global electrophilicity index (ω), nucleophilicity (ε) and others were determined. The quantum chemical parameters calculated revealed that QZO is relatively more nucleophilic in nature and potentially a better inhibitor. The Fukui indices values discovered that the hetero atoms (N, O and S) of the studied compounds are responsible for their inhibitive characteristics. According to the calculated binding and adsorption energies obtained from the quenched molecular dynamic simulations, the relatively low values obtained of less than 100 kcal/mol results in the molecules being weakly adsorbed onto the surface of Al(1 1 0) through van der Waals forces and consequently obey the physical adsorption mechanism in the order: QZO>QZT> QZN. The examined molecules' varied bond lengths and angles before and after adsorption on the Al(1 1 0) surface demonstrate the nature of adsorption and the molecules' non-planarity on the surface of the metal. QZO and QZT have larger molecular sizes and additional hetero atoms (O and S), making them possibly more corrosion-inhibitive on Al(1 1 0) surfaces than QZN.
Treatment of Tire Industry Wastewater through Adsorption Process using
Waste Tire Rubber
- Abstract: Attempts to use waster rubber powder as an adsorbent of pollutants in wastewater treatment applications is an environmentally friendly, efficient and novel method, especially in the tire industry wastewater treatment process. This study evaluated the efficiency of waste tire rubber powder in adsorbing the tire industry wastewater. The rubber and The wastewater were prepared from Kavir Qom Co. and Artawheel Tire Co., respectively. Comparison of UV-vis spectrophotometer results of the nontreated wastewater with the wastewater data after adsorption under various thermal and temporal conditions indicated that the tire powder adsorbent has the necessary efficiency for treating the tire industry wastewater. Examination of data with pseudo-first- and second-order kinetic models also confirmed the adsorbent’s efficiency and showed that the second-order kinetic model had a good correspondence with the obtained results.
Microbial Iron Chelators: A Possible Adjuncts for Therapeutic Treatment of
SARS-CoV-2 like Viruses
- Abstract: There is a need for targeted, effective antiviral therapeutic treatment for the global threat of COVID-19, like viral pandemics. Our efforts in this direction present the in-silico testing of a hypothesis through molecular docking. We have demonstrated the possibility of a microbial siderophore desferrioxamine-E produced by Pseudomonas stutzeri SGM-1 for effective drug targeting and drug development against SARS-CoV-2, like viruses. Iron homeostasis and COVID-19 have a close relationship. An iron chelator desferrioxamine-E binding with the SARS-CoV-2 virus can inhibit the viral RNA binding and packaging into the new virions inside the host cell. The well-known efficacy of iron chelation and RNA binding domain of SARS-CoV-2 nucleocapsid interaction of desferrioxamine-E studied through molecular docking has promising potential for exploring microbial iron chelators as adjuncts for in-silico clinical trials and randomized clinical trials.
A 2-D QSAR Modeling, Molecular Docking Study and Design of
2-Arylbenzimidazole Derivatives as Novel Leishmania Inhibitors: A
Molecular Dynamics Study
- Abstract: Leishmaniasis, a neglected tropical disease, affects a human population of over 12 million people, mainly in the tropics, and is caused by the leishmanial parasites transmitted by the female sand fly. The lack of vaccines to prevent leishmaniasis, and the limitations of existing therapies necessitated this study, which was focused on the computational design of some novel 2-arylbenzimidazole analogs while subjecting the same to molecular docking, pharmacokinetics, and Molecular Dynamic (MD) simulation to ascertain their drug-ability. The obtained QSAR model was validated as follows: R2 = 0.8447, R2adj = 0.8095, Q2cv = 0.6799, and R2test = 0.7383. The predicted pIC50 values of all newly designed compounds were higher than that of the lead compound (13). The newly designed analogs conformed to Lipinski's rule for oral bio-availability less 13m, and showed good ADMET properties, with 13j showing the highest Human Intestinal Absorption (HIA) of 93.64%. The MD simulation result demonstrated excellent stability associated with the binding of 13j onto 6K91's binding pocket with an estimated ∆G binding (MM/GBSA) of -50.4031 kcal/mol than that of 13_6K91 (∆G binding = -25.9665 kcal/mol). Therefore, 13j could be recommended as a potential drug molecule for treating leishmanial infections. 
Perspective on Metal-Ligand Coordination Complexes and Improvement of
Current Drugs for Neurodegenerative Diseases (NDDs)
- Abstract: Neurodegenerative diseases (NDDs) associated with the steady loss of neural functionality by the action of irreversible damage or death of neurons are one the most serious diseases amongst human beings. The most common NDDs are including Alzheimer’s disease, Prion protein disease, and Parkinson’s disorder. Several coordination complexes are effective in the treatment of NDDs. In the present scenario, computational methods opened a new vista for novel drugs with theoretically improved overall effectiveness. This review highlights the current trends of computational designs of coordination complexes in developing new drug discovery options and their potential to treat different neurodegenerative diseases with up-to-date R&D exploration with future perspectives.
(S)-N-(4-Carbamoylphenyl)-8-Cyclopropyl-7-(Naphthalen-1-ylmethyl)-5-Oxo-2,3-Dihydro-5H-Thiazolo[3,2-a]Pyridine-3-Carboxamide,
A Better Inhibitor of SARS-Cov-2 Spike Glycoprotein Than Some Standard
Drugs: A Computational Prediction
- Abstract: The appearance of severe acute respiratory syndrome coronavirus 2 (COVID-19) is at its peak; with the growing number of people infected with COVID-19, there is an urgent need to find effective treatments for this outbreak. The current situation appears to call for drug repurposing. In our hunt for a viable medication against this virus, we used an in-silico strategy to test four conventional medicines, including Ritonavir and Hydroxychloroquine, against the spike glycoprotein of COVID-19. A docking simulation was performed to assess the drug's binding affinity. We discovered a single medication compound 36 against SARS-coronavirus spike glycoprotein. The compound was found to have a strong binding affinity against the target protein. The chemical was discovered to have a high affinity for the target protein. Furthermore, no conventional medicines efficiently bonded to the SARS-coronavirus spike glycoprotein. The current investigation concluded that the compound 36 is a highly stable anti-SARS-coronavirus spike glycoprotein medication. Furthermore, none of the standard drugs had a high affinity for the SARS-coronavirus spike glycoprotein binding site. 
Production of Methyl Ester from Used Cottonseed Oil Optimized Using Box
Behnken Design Approach
- Abstract: Worldwide interest in biofuels, such as biodiesel and biogas as alternatives to fossil fuels, is growing. The transesterification method is usually applied in the production processes of biodiesel because of its numerous advantages. The viscosity of the oil sample was decreased by utilizing this technique. The production procedure of methyl ester is determined by the amount of free fatty acids (FFA) in the sample. The titration technique was employed to evaluate this for the crude cottonseed oil (CCSO) and used cottonseed oil (UCSO), with the following results: 0.56 % and 1.26 %. Heterogeneous alkali (calcined commercial CaO) catalyzed transesterification was used to convert UCSO into used cottonseed oil methyl ester (UCSOME). It involves the reaction of methanol with UCSO in the presence of the catalysts. Some of the reaction parameters that control the transesterification process were; the methanol-oil ratio, reaction temperature, reaction time, and catalyst concentration. The aforementioned parameters were optimized through the response surface approach; Box-Behnken Design (BBD). The response surface yield has been plotted graphically as part of the various parameters that improve biodiesel yield. An optimized UCSOME yield of 93.60 % was obtained at a 1:10 molar ratio, 2.5 wt.% catalyst concentration, 80-min reaction time, and 60 °C reaction temperature. 94.50 % was the experimental yield obtained based on these parameters, which shows that the response surface methodology is a successful technique for optimizing the yield. The purity of the methyl ester was determined using GC-MS and FTIR.