Studies on the synthesis and antifungal activity of thiochromanone derivatives

In this paper nine New Mannich bases of 6-fluoro-thiochromanone and eight new 3-substituted-6.8-dichloro thiochromanones were synthesized and their structures were confirmed by IR, H-1-NMR and elementary analysis. Most of these compounds showed excellent antifungal activity.

Preparation, Characterization and Antimicrobial Studies of Mn(II) and Fe(II) Complexes with Schiff Base Ligand Derived from 2-aminophenol and 3-formyl-2-hydroxy-6-methoxyquinoline

Schiff base derived from 2-aminophenol and 3-formyl-2-hydroxy-6-methoxyquinoline and its Mn(II) and Fe(II) complexes were synthesized and characterized by melting point and decomposition temperature, elemental analysis, molar conductivity, infrared (IR) spectral analysis, atomic absorption spectroscopy (AAS) analysis, solubility test, and magnetic susceptibility. The Fourier-transform infrared spectroscopy (FTIR) spectral data of the Schiff base determined showed a band at 1622 cm−1 and this was assigned to the v (C=N), which is a feature of azomethine group. The same band was observed to shift to lower frequencies 1577 and 1599 cm−1 in the complexes suggesting coordination of the Schiff base with the respective metal(II) ions. Molar conductance values 14.58 and 12.65 Ω−1∙cm2∙mol−1 show that the metal complexes were non-electrolyte in nature. The magnetic susceptibility of the complexes was determined and the gram magnetic susceptibility of the complexes was found to be positive, revealing that they are paramagnetic. The elemental analysis of the complexes for C, N and H determined suggested 1:1 metal to ligand ratio. The result of the antimicrobial studies showed that, the metal(II) complexes exhibited better antibacterial and antifungal activity than the Schiff base.

Biosynthesis of gold nanoparticles using aqueous extract of Ricinus cummunis leaves to augment catalytic degradation of organic dyes and study of its antifungal and antibacterial activities

In this study,biosynthesis of gold nanoparticles(Au NPs)using aqueous extract of fresh leaves of Ricinus cummunis plant is reported without the use of any synthetic chemical in the reaction process.The prepared NPs are mostly spherical in shape with some particles having triangular or hexagonal struc-tures.The average size of the particles as calculated using TEM data is 18 nm.The biosynthesised Au NPs were studied for their application in remediation of Congo Red,Methylene Blue,Reactive Red 120 and Rhodamine B dyes present in industrial effluents.The degradation of dyes was confirmed spectropho-tometrically using UV-Vis Spectrophotometer.Reactive Red 120 and Congo red dyes were most effec-tively reduced with 88%degradation.The Au NPs were further studied for their potential as an effective antifungal agent against fungal strains namely Candida albicans and Aspergillus fumigatus and antibac-terial properties against Bacillus subtilis(Gram+ve)and Pseudomonas aeruginosa(Gram-ve)bacterial strains.The MIC values being 7.8 and 15.6(μg/mL)for Bacillus subtilis and Pseudomonas aeruginosa respectively.