Posted by admin on Jul 1, 2014 in |
The present paper deals with synthesis and characterization of some new chromium (III) Schiff base complexes using microwave irradiation technique as well as conventional heating. The S∩N donor benzothiazolines, 1-(2-furanyl) ethanone benzothiazoline (Bzt1N∩SH), 1-(2-thienyl) ethanone benzothiazoline (Bzt2N∩SH) and 1-(2-pyridyl) ethanone benzothiazoline (Bzt3N∩SH) were prepared by the condensation of ortho-aminothiophenol with respective ketones in ethanol. The chromium (III) complexes have been prepared by mixing CrCl3∙6H2O in 1:1 and 1:2 M ratios with benzothiazolines. The structure of the ligands and their transition metal complexes were confirmed by the elemental analysis, melting point and molecular weight determinations, IR, 1H NMR, electronic, EPR spectral studies. On the basis of these studies an octahedral environment around the chromium (III) ionhas been proposed. The in vitro antimicrobial and in vivo antifertility activities of Schiff base ligands and their respective chromium (III) complexes were performed on pathogenic bacterial and fungal strains and male albino rats respectively. The results indicated that the complexes showed higher activity than the parent...
Read More
Posted by admin on Jun 1, 2014 in |
The coriander seedextract in 80% methanol is examined for the polyphenol composition and the antimicrobial potential against pathogenic bacteria Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus pumilus. Gallic acid, caffeic acid, ellagic acid, quercetin and kaempferol are principle polyphenolics identified and quantified in the coriander extract by HPLC. The antimicrobial activity was examined by determining cell damage and measuring cell inhibition zone. The growth inhibition zones observed by agar well diffusion method are 11.93 to 17.27 mm in diameter in presence of coriander extract. Minimum inhibitory concentration of coriander was 4.16 mg/ml for the bacteria tested. Increased release of intracellular nucleotides and proteinaceous materials from the bacterial cells in the presence of methanolic coriander extract suggests that the primary mechanism of action of coriander extract is membrane damage, which leads to cell death. The results obtained herein further encourage the use of coriander in antibacterial formulations due to the fact that polyphenol rich coriander extract could effectively kill pathogenic bacteria related to foodborne...
Read More
Posted by admin on Jun 1, 2014 in |
A series of new 1H-benzo[d]imidazole derivatives of 3, 4-substituted triazole. 3-(1H-Benzo[d]imidazol-2-ylsulfanyl) methyl-4-[phenyloxy(phenylacetamido)]-5-mercapto-1,2,4-triazole and related aryloxy compounds were synthesised, analysed and characterised by FTIR, 1HNMR and elemental analysis. These compounds were screened for antibacterial and antifungal activity. The antibacterial activities were compared against chlorophenicol and antifungal activity with mycostalin. Some triazole derivatives showed a little antibacterial but appreciable antifungal...
Read More
Posted by admin on May 1, 2014 in |
The main objective of this work is to study the stereostructures and biological activity of some highly substituted cyclohexenes, cyclohexanols and the intermediates there in. In order to get the desired cyclohexenes, the synthesis of cyclohexanols 2,4-bis(4-chlorobenzoyl)-1-(4-chlorophenyl)-3,5-bis(4-methoxyphenyl)-and 2,4-bis(4-chlorobenzoyl)-1,3,5-tris(4-chlorophenyl)-cyclohexan-1-ols (1b and 2b) from 4’- chloro-4-methoxy- and 4,4’- dichlorochalcones(1 and 2) via 1,5-bis(4-chlorophenyl)-3-(4-methoxyphenyl)- and 1,3,5-tris(4-chlorophenyl)-pentan-1,5-diones(1a and 2a ) using p-chloroacetophenone in the presence of sodium hydroxide(molar ratio, 2:1:10) is first described. These are then dehydrated with p-TsOH which afford typical cyclohexenes, 4,6-bis(4-chlorobenzoyl) -1- (4-chlorophenyl) – 3,5 –bis (4-methoxyphenyl) and 4,6 –bis(4-chlorobenzoyl)-1,3,5 –tris (4-chlorophenyl) –cyclohex-1-enes (1c) and (2c) in quantitative yields containing β,γ-unconjugated double bond following stereoselective syn elimination. Also, in an attempt to synthesize dithiazolidin-4-one (3), the reaction of 1, 5-dione (1a) with mercapto acetic acid and ammonium carbonate is adopted. However, it fails to produce (3) and only a pyridine derivative, 2, 6-bis (4-chlorophenyl)-4-(4-methoxyphenyl) pyridine (4) is obtained.in 87% yield. Structural assignment, stereochemistry and biological assays are discussed. The characterization is done by modern spectroscopic...
Read More
Posted by admin on May 1, 2014 in |
The aqueous and methanol extracts of the seeds of Moringa oleifera (Family: Moringaceae) and the seeds of Mormordica charantia (Family: Cucurbitaceae) were screened for their antimicrobial activity against three human pathogenic bacterial strains and three fungal strains by agar-well diffusion assay. The pattern of inhibition varied with the solvent used for extraction and the microorganisms tested. Among these extracts, methanol extract showed significant antimicrobial activity against all the six tested microbes. The most susceptible microorganism was Staphylococcus aureus which showed 8 mm and 7 mm zone of inhibition with methanol extract of M.oleifera and M.charantia respectively. M.oleifera methanol extract was significantly effective against the fungi C.albicans as comparable to the standard flucanozole. Preliminary phytochemical analysis of different extracts revealed the presence of flavonoids, terpenoids and tannins in M.oleifera methanol extract and the presence of alkaloids, glycosides and tannins in M.charantia methanol extract. These compounds may have contributed to their antimicrobial...
Read More
