Chemical Review and Letters

Abstract In the Gram-negative pathogen Yersinia pseudotuberculosis and Chlamydia, the aggregate use of molecular docking, molecular dynamic simulations, and ADMET was successfully used to develop salicylidene acyl hydrazides as type III secretion (T3S) inhibitors. The molecular docking analysis was carried out on CMP's simulated protein, which helped to correlate amino acid associations with the ligand. The review of molecular dynamics simulations showed that the CMP protein A-chain was stable at and above 100ps concerning temperature, total energy, and kinetic energy. Virtual screening was performed to distinguish the new inhibitors depending on pharmacophore modeling and molecular docking. Based on the Rerank score fitness feature, ten top-ranked compounds were discovered. In keeping with the reference ranges, ADME tests were carried out on compounds retrieved from simulated sampling. For our further drug design, all the findings will give us more useful evidence.

Abstract Studies and scientific research indicate that the platelet-activating factor (PAF) is a major pro-inflammatory mediator in the initiation and development of cancer. There is also evidence confirming that PAF is an integral part of suppressing the immune system and promoting the appearance of a malignant tumor. For this reason, it is useful to analyze the molecular docking data of eleven flavonoids derivatives isolated from the active leaf extracted from chromolaena odorata with their anti-PAF activity. As a result, it is evident that the natural product of flavonoids may have a positive effect in the development of both therapeutic and preventive agents for platelet activating factor (PAF) antagonist and suggests potential guidelines for the design of PAF inhibitors. Based on the docking score analysis, drug likeness study, and ADMET prediction. We found that six compounds respect all drug-likeness rules and can be used as a potent molecule for inhibition of platelet activating factor (PAF).

Abstract An environmentally benign, simple, and efficient procedure has been developed for the construct of some symmetrical dispiroheterocycles derivatives by the reaction of the variety of 6-amino-2-thiouracil/6-aminouracil /2-amino-1,3,4-thiadiazole, isatins and p-toluidine in the presence of 1-Butyl-3-methylimidazolium bromide ([bmim]Br) as a solvent as well as catalyst at room temperature. In this study, a variety of bis-spiro-indoline-chromenes, pyranopyranes, imidazo-pyridines, pyrido-pyrimidines and pyridines were obtained with excellent yields within short reaction time and without chromatographic separation. Furthermore, the green catalytic system can be recycled specific times with no decreases in yields and reaction rates.

Abstract The concentrations of heavy metals namely; chromium, cadmium, lead and nickel (Cr, Cd, Pb and Ni) were determined from twelve samples of rice(ORYZA SATIVA) , the samples comprises of six foreign samples and six local samples collected from different markets within Funtua Local Government Area in 2019. The samples were digested in aqua region and the level of heavy metals were determined using Atomic Absorption Spectrophotometer AA500FS Model. Concentrations of the heavy metals in the rice samples were in the order Cr > Pb > Ni > Cd. The highest concentration of cadmium was detected in LR1(0.620mg/kg) and LR5(0.626mg/kg) while the lowest was detected in FR5(0.058mg/kg). The lowest concentration of nickel was detected in in FR6(0.060mg/kg) and LR2(0.090mg/kg) while the highest was detected in LR3(0.910mg/kg) and LR4(0.750mg/kg). The highest concentration of lead was detected in FR6(0.650mg/kg) and LR1(0.580mg/kg) while the lowest was detected in LR2(0.199mg/kg) and LR5(0.212mg/kg). The highest concentration of chromium was detected in LR1(0.840mg/kg), LR4(0.840mg/kg) and FR5(0.760mg/kg) while the lowest was detected in LR6(0.050mg/kg) and FR2(0.080mg/kg). The analysis shows that chromium, nickel, and lead concentrations that accumulated almost all the rice samples exceeded the maximum permissible limits prescribed by the World Health Organization guideline as well as the Food And Agricultural Organization standard. Cadmium concentrations were found in almost all the samples to conform with the standards. The higher levels of heavy metals accumulated by the samples may be attributed to the increase in agricultural activities such as the application of phosphate fertilizer, sewage sludge disposal and other anthropogenic activities which deserve further investigations.

Abstract New homobinuclear complexes of Co(II) and Ni(II) with a Schiff base, N,N’-bis(4-methoxybenzylidene)thiourea derived from [2+1] condensation reaction of 4-methoxybenzaldehyde and thiourea have been synthesized by conventional method. The Schiff base ligand and the complexes were characterized as appropriate by gravimetric determination of chloride content, thermogravimetric estimation of uncoordinated water, melting point, molar conductance measurement and infrared spectroscopy. The ligand was white crystalline solid of sharp melting point (150 oC) whereas the Co(II) and Ni(II) complexes were blue and golden colour with decomposition temperature of 190 oC and 198 oC, allusive of thermostability. Both complexes were hydrated and non-electrolytic in nature with four chloride ions coordinated to the bimetallic ions. The IR study revealed that the ligand is a neutral tridentate diazamonothio moiety coordinated to the Co(II) and Ni(II) ions through its two azomethane nitrogen atoms (C=N) and thione sulphur. The resultant data suggest formation of the homobinuclear complexes as [M2LCl4].nH2O, (where M2+=Co or Ni, L=Schiff base ligand and n=4 for Co and 6 for Ni complex), possessing square planar structure.

Abstract The present study aimed to assess the adsorption of Lomustin on the single-walled Boron Nitride nanotube which has been examined using Density Functional Theory (DFT), agent in a solvent phase (water) at the B3LYP/6-31G (d) theoretical level. Initially, the structures of Lomustin, Boron Nitride nanotube, and Lomustin complexes with Boron Nitride nanotubes were designed in Gauss View in three different conformers and were optimized geometrically, on which IR and frontier molecular orbital computations were carried out. Adsorption energy values, Gibbs free energy changes (ΔGad), adsorption enthalpy changes (ΔHad), and equilibrium thermodynamic constants were estimated. The results showed that adsorption process was spontaneous, exothermic and non-equilibrium. The values of specific heat capacity and adsorption enthalpy indicate that this nanostructure can be used to build new thermal sensors to measure Lomustin. The results of molecule orbitals estimations showed that energy gap, after drug absorption on the nanotube surface, decreased significantly and the values of chemical hardness and dipole moment were studied after the interaction of drug with adsorbent and the results showed that drug solubility and reactivity, after adsorption on Boron Nitride nanotubes, increased significantly. According to the obtained results for adsorption of Lomustin, this nanostructure can be used as a sensing material in building new electrochemical sensors to measure this drug.

Abstract A series of metal-organic frameworks (MOFs), including aluminum terephthalate (AlTp), bismuth terephthalate (BiTp), and chromium terephthalate (CrTp), was synthesized for use as inhibitors to protect AM60B magnesium alloy from corrosion in 30% ethylene glycol solution containing 0.5 M NaCl. The prepared MOFs were characterized using the X-ray diffraction (XRD) spectrum, Brunauer, Emmett, and Teller (BET), and scanning electron microscope (SEM) images. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization were applied to evaluate the inhibition performance of the MOFs in a concentration range of 50-400 ppm. Inhibition efficiencies of 84.17%, 86.52%, and 89.64% were obtained for BiTp, AlTp, and CrTp at an optimum concentration of 200, 400, and 400 ppm, respectively, indicating high potentials of the proposed inhibitors. Gibbs free energy of adsorption obtained for BiTp, AlTp, and CrTp were as -30.016, -26.725, and -25.792 kJ mol-1, respectively. These results revealed that the inhibitors were adsorbed on the metal surface through both physisorption and chemisorption processes.