Adamu Uzairu

Risk Assessment of Heavy Metals in Imported Frozen Fish Scomber scombrus Species Sold in Nigeria: A Case Study in Zaria Metropolis

This study assesses the likely health risks to human contamination of heavy metals from fish consumption. The analysis of the idea of fish destination and status (fishing area) for heavy metals was determined by the assessment of its risk limits (daily intake of metal and health risk index). Variations in the accumulation of heavy metals concentrations were between various tissues/organs (skin, muscle, gills, liver, intestine, kidneys, brain, and bones) across the batches of two fishing origins. Post hoc (Duncan) multicomparison shows that there are significant differences () across batches. The concentrations of heavy metals analyzed, in the investigated tissues of Scomber scombrus, showed higher levels of heavy metals accumulations in the order: and were above the recommended safety limits outlined by FAO/WHO. However, the consumer’s health risk with the consumption of fish muscles tissues shows that there are greater tendencies for cadmium, lead, and mercury exposure. Also consumption of Scomber scombrus species above the recommended daily intake (stated in this study) might lead to ingestion of heavy metals at unacceptable concentrations.

Quantitative structure-activity relationship and molecular docking studies of a series of quinazolinonyl analogues as inhibitors of gamma amino butyric acid aminotransferase.

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MNDO and DFT Computational Study on the Mechanism of the Oxidation of 1,2-Diphenylhydrazine by Iodine

The reaction mechanisms of the oxidation of 1,2-diphenylhydrazine by iodine have been examined using semiempirical and density functional theory methods, the oxidation proceeded via two independent pathways that can be separately monitored. One pathway involved the chain multistep mechanism. The other pathway occurred via a one-step mechanism in which a “cyclic” activated complex was formed which on disproportionation gave the products. The one-step “cyclic” activated complex mechanism proceeds more rapidly than the chain multistep mechanism. The results were explained by analyses based on computational energetics of the optimised reactants, intermediates, transition states, and products of the reaction of iodine with 1,2-diphenylhydrazine.

QSAR Modeling and Molecular Docking Analysis of Some Active Compounds against Mycobacterium tuberculosis Receptor (Mtb CYP121)

A quantitative structure-activity relationship (QSAR) study was performed to develop a model that relates the structures of 50 compounds to their activities against M. tuberculosis. The compounds were optimized by employing density functional theory (DFT) with B3LYP/6-31G⁎. The Genetic Function Algorithm (GFA) was used to select the descriptors and to generate the correlation model that relates the structural features of the compounds to their biological activities. The optimum model has squared correlation coefficient (R2) of 0.9202, adjusted squared correlation coefficient (Radj) of 0.91012, and leave-one-out (LOO) cross-validation coefficient (Qcv2) value of 0.8954. The external validation test used for confirming the predictive power of the built model has R2pred value of 0.8842. These parameters confirm the stability and robustness of the model. Docking analysis showed the best compound with high docking affinity of −14.6 kcal/mol which formed hydrophobic interaction and hydrogen bond with amino acid residues of M. tuberculosis cytochromes (Mtb CYP121). QSAR and molecular docking studies provide valuable approach for pharmaceutical and medicinal chemists to design and synthesize new anti-Mycobacterium tuberculosis compounds.

Distribution Pattern of Metals in Atmospheric Settling Dust along Roads in Kano Metropolis, Nigeria

The sequential extraction of Cd, Cr, Ni, Pb, Cu, and Zn in atmospheric dust particles collected along ten high traffic roads in Kano metropolis was carried out. Analyses of metals in the extracts were done using flame atomic absorption spectrometry (FAAS). The samples analyzed for metals indicated high levels of Cd, Cr, Ni, Pb, Cu, and Zn in the atmospheric dust samples. The sequential extractions that showed significant amount of Cd were associated with and Fe-MnO fractions especially during the dry seasons. For Cr and Ni, their occlusion in crystal lattice of the soil fraction exhibited the highest percentage. Pb in the particulate dust samples is significantly associated with the carbonate bound fraction with range of 8.81–64.69% across the season. The behaviour of Cu is quite different from other metals in that percentage fractions are higher in the organic bound. As for Zn, significant amounts were associated with the residue fractions ranging from 0.96 to 87.50% across the seasons. This study revealed contamination of the particulate dust with Cd and Pb; this implies health risks to human, living or carrying out daily activities along the corridors of these roads.

Physicochemical studies and rheological modelling of Albizia lebbeck (AL) gum exudates

Purpose – The purpose of this study is to determine the physicochemical and rheological parameters of Albizia lebbeck gum. Design/methodology/approach – Physicochemical analysis was carried out using recommended methods. Gas chromatography mass spectrophotometer and Fourier transformed infra red (FTIR) analyses were carried out using their respective spectrophotometer. Scanning electron microscopy was carried out using scanning electron microscope, while rheological measurements were carried out using Ubbelohde capillary viscometer, digital Brookfield DV 1 viscometer and a rheometer. Findings – Albizia zygia gum is an ionic gum with unique physical and chemical properties. Scanning electron micrograph revealed that the internal structure of the gum is porous with irregular molecular arrangement. Thermodynamic parameters of viscous flow indicated the existence of few inter- and intra-molecular interactions, and the attainment of transition state was linked to bond breaking. Coil overlap transition studies ...

The Use of Glutamic Acid as Corrosion Inhibitor for Aluminium in Hcl Solution

The adsorptive and inhibitive action of glutamic acid towards general and pitting corrosion of aluminium in HCl solution was investigated using weight loss, gasometric and thermometric methods. Glutamic acid was found to inhibit the corrosion of aluminium in HCl solution. The inhibition efficiency of glutamic acid decreased with increase in temperature, period of immersion and HCl concentration, but increased with increasing glutamic acid concentration. Adsorption characteristics of glutamic acid have also been studied and it was found that the process obeys physical adsorption. Thermodynamic parameters including; Ea, Qads, ∆Sads, ∆Hads and ∆Gads for the adsorption process signifies a spontaneous process. While Langmuir, Frumkin, Flory- Huggins and El-Awardy isotherm adsorption models can be used to explain the mechanism of glutamic acid adsorption onto aluminium surface in HCl solution.

Molecular docking and QSAR analysis of a few Gama amino butyric acid aminotransferase inhibitors

Abstract Molecular docking and quantitative structure–activity relationship (QSAR) studies were carried out on 37 anticonvulsant compounds to develop a robust model for the prediction of anticonvulsant activities against Gama amino butyric acid aminotransferase (GABAAT) and to determine the dominant structural amino acid residues responsible for the binding affinity of the ligand-GABAAT complex. AutoDock Vina of PyRx virtual screening software was used to perform the molecular docking while Genetic function algorithm (GFA) was used to select the descriptors and to generate the correlation models that relate the structural features to the biological activities. The best binding affinity was found to be −11.9 Kcal/mol (compound 5a) while best QSAR model (model 1) was obtained with R2 of 0.970192, an R2adj value of 0.963095, Q2LOO value of 0.947995 and R2pred of 0.813. These confirms the stability, reliability, robustness and predictability of the model. Our research has shown that the binding affinity generated was found to be better than the one reported by another researcher. And the high correlation coefficient, (R2) shows that the model was reliable, robust and predictable. Our QSAR model and molecular docking results corroborate with each other (most especially in the area of binding affinity and atomic electronegativity of the inhibitors) and propose the directions for the design of new inhibitors with better activity against an enzyme that is responsible for epilepsy (GABAAT).

In silico modelling of quantitative structure–activity relationship of multi-target anticancer compounds on k-562 cell line

The pGI50 cytotoxicity values of 112 compounds on K-562 cancer cell line were modeled to illustrate the quantitative structure–activity relationship (QSAR) of the compounds. The dataset were divided into training and test set through Kennard-stone algorithm, while the pool of molecular descriptors calculated with paDEL descriptor metric program was subjected to the genetic functional algorithm (GFA) for selection of descriptor to be modeled. The best QSAR model developed was then subjected to a rigorous statistical test. The statistical significance of the model was verified by calculating the values of Q2LOO (0.845), Q2F1 (0.9397), Q2F2 (0.6862) and R2pred (0.6862) needed to evaluate the strength and robustness of the model. The result of the internal and external validation of the model indicates that the model is good and could be used to predict the GI50 of anticancer compounds on K-562 leukemia cell line. The model developed was used in designing new anticancer drugs with higher activity or more potent and less toxic in nature when compared to the lead compound. These compounds significant activities were found to correlate to with some of the molecular descriptors such as the number of hydrogen bond acceptors present in the surface of the molecule.

Mechanism and rate constant of proline-catalysed asymmetric aldol reaction of acetone and p-nitrobenzaldehyde in solution medium: Density-functional theory computation

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