Showing papers in "Journal of Advances in Chemistry in 2019"

Structural And Vibrational Studies on Isomers of Antiviral Ribavirin Drug in Gas and Aqueous Environmental by Using The SQM Approach

Abstract: Five stable isomers of antiviral ribavirin agent were theoretically determined in gas and aqueous solution by using the hybrid B3LYP/6-31G* method. Here, the solvent effects were studied with the self consistent reaction field (SCRF) methodology employing the polarized continuum (PCM) and the universal solvation model (SM). Structural, electronic and topological properties were reported for all isomers while the vibrational analyses were performed only for those two polymorphic structures experimentally observed in the solid phase by X-ray diffraction. Calculations have evidenced that C2 correspond to the polymorphic V1 structure while C5 to the polymorphic V2 structure. The high dipole moment values predicted for C2 and C5 in both media could probably explain their presences in the solid. Experimental available IR and Raman spectra of ribavirin in the solid state and normal internal coordinates were employed together with the scaled quantum mechanical force field (SQMFF) approach to perform the complete vibrational assignments in both media. Here, the 81 vibration modes expected for C2 and C5 in both media were completely assigned. The frontier orbitals studies reveal that C5 is the less reactive in both media. Here, the gap value observed for C5 is in agreement with the value recently reported for ribavirin by using B3LYP/6-311++G** calculations.

Synthesis, Spectral Characterization, Thermal and In vitro Antimicrobial Studies for Novel Co(II) and Ni(II) Complexes of (N,N'-(1,2-Phenylene)Bis(2-Aminobenzamide)

Abstract: Novel metal complexes of Co(II) and Ni(II) have been prepared from reaction of their different salts with previously prepared ligand (L) namely (N,N'-(1,2-phenylene)bis(2-aminobenzamide). Synthesis ligand and its metal (II) complexes (1-5) were reported and characterized with the help of analytical and physiochemical analysis as elemental, IR spectra, thermal (TG/DTG), UV-Vis, magnetic susceptibility and molar conductance in DMF, On the view of the previous data and measurements, the structure and composition species behave as mononuclear and octahedral geometry has been proposed for all the complexes except for complex (1) adopted tetrahedral structure. Furthermore, the in vitro antibacterial Staphylococcus aureus (ATCC 25923) as Gram-positive strain, Escherichia coli (ATCC 25922) as Gram-negative strain and antifungal Candida albicans (ATCC 10231) have been studied for all samples using disc diffusion method against Ampicillin and Fluconazole as positive controls, respectively. The results show that complexation facilitates the activity of most studied metal complexes than the free ligand.

Study on the Properties of PTMG Oughener Modified Epoxy Resins

Abstract: The E-51 epoxy resin was modified by PTMG toughener. The resin was cured under high temperature methyl tetrahydrophthalic anhydride (MeTHPA) as Tris(dimethylaminomethyl)phenol (DMP shows that PTMG significantly reduced the glass transition temperature of test results shows that the presence of PTMG in the cured material increased maximum impact strength was achieved modulus, flexural strength, and fle smaller than the valve value, PTMG increased the cured material’s tensile and flexural strength as well as its tensile and flexural modulus. While the mass fraction of PTMG was larger than increase of the mass fraction of PTMG reduced the cured material’s strength and modulus.

Levels of Toxic Metals in Skin Lightening Agents Marketed in Nigeria

Abstract: Background: Bleaching agents produced by registered companies in developed countries have regulated concentrations. But various local skin lightening agents produced in Africa, especially Nigeria have no identified active agent. This study determined the levels of potentially toxic heavy metals constituents of bleaching agents commonly used by Nigerians. Methods: Twelve different types of skin lightening creams (Extra white, Make me white, Extract, Perfect white, UV lightening, Pure skin, Body treat, Dodo up, Bronze tone, White express, Peau Claire and Otentika) available Nigerian markets were randomly collected based on their usage and availability. Three non- lightening creams served as the controls for this study. Levels of mercury, lead, cadmium, chromium and arsenic were determined in both lightening and non- lightening creams (controls) using atomic absorption spectrophotometer (AAS). Results: All lightening creams 12/12 (100%) contained significantly (pl0.05) higher levels of mercury compared with the control. 11/12 (91.7%) of the lightening creams contained significantly (pg0.05) higher levels of lead compared with the control. Levels of arsenic were significantly (pl0.05) higher in 11/12 (91.7%) of the lightening creams compared with control. Levels of cadmium increase significantly (pl0.05) in 4/12 (22.92%) of the lightening creams compared with the control. 4/12 (22.92%) of the lightening creams contained significantly (pl0.05) higher levels of chromium compared with control.

Chemical Speciation and Mobility of Heavy Metals in Soils Around Nasara Sack and Packaging Company Akwanga, Nigeria

Abstract: This study quantified and assessed the mobility of iron, nickel, cobalt and lead in soils around a sack and packaging company using indices such as mobility factor and risk assessment code. The results evaluating the mobility factor of heavy metals in soils around the sack and packaging company reveal that all the metals determined exceed the minimum limit of 10% mobility factor and are mobile with the mobility factor being in the order of: Ni > Pb > Co > Fe in the test soil. The risk assessment of heavy metals in the area based on risk assessment code ranged from low risk to medium risk (1-30%) where the risk level of the heavy metals is in the order: Co > Ni > Pb > Fe in the test soil.

Synthesis, Spectroscopic Characterization And Antimicrobial Evaluation of Novel Nitrogen Containing Metal Complexes

Abstract: Four novel Mn(II), Co(II), Cu(II) complexes with nitrogen containing ligand (L) i.e. N,N-((Z)-ethane-1,2-diylidine)bis(2-amino benzo hydrazide) have been synthesized and structurally characterized by elemental analysis, spectral, thermal (TG/DTG), molar conductance and magnetic susceptibility measurements. From the spectroscopic and magnetic studies it has been concluded that all complexes have a six coordinated octahedral geometry. The Schiff base and their metal complexes have also been screened for their antibacterial and antifungal activities by using a modified Kirby-Bauer disc diffusion method.

The Clitocybins and 2-Substituted-Isoindolin-1-Ones: Synthesis and in Vitro Antimycobacterial Activities

Abstract: Despite strong indications of antimycobacterial activities for clitocybins reported since 1945, no reports linking chemical structure and activity have been reported in the literature since then. In this study, we synthesized some clitocybin derivatives (also called 2-substituted-isoindolinones), and tested their activities and carried out some chemical derivations. Isoindolinones were prepared from methyl 2-formyl-3,5-dimethoxybenzoate and various primary aromatic amines. Compounds were evaluated for in vitro activity against Mycobacterium tuberculosis H37Rv, as well as for cytotoxicity (CC50) on the Vero cell line. 4,6-dihydroxy-2-(4-hydroxyphenyl)isoindolin-1-one, 7, and 4-hydroxy-2-(4-hydroxyphenyl)-6-methoxy-isoindol-1-one, 5, exhibited the highest antimycobacterial activities (minimum inhibitory concentration = 19.45 µM and 18.45 µM, respectively) and were non-toxic (CC50 = 30 µM and 29 µM, respectively).