A series of cobalt(III) mixed ligand complexes of type [Co(en)2L]+3, where L is bipyridine, 1,10-phenanthroline, imidazole, methylimidazole, ethyleimidazole, dimethylimidazole, urea, thiourea, acetamide, thioacetamide, semicarbazide, thiosemicarbazide, or pyrazole, have been isolated and characterized. The structural elucidation of these complexes has been explored by using absorption, infrared, and 1H NMR nuclear magnetic resonance spectral methods. The infrared spectral data of all these complexes exhibit a band at 1450/cm and 1560-1590/cm, which correspond to C=C and C=N, a band at 575/cm for Co-N (en), and a band at 480/cm for Co-L (ligand). All these complexes were found to be potent antimicrobial agents. The antibacterial activity was studied in detail in terms of zone inhibition, minimum bactericidal, and time period of lethal action. Among all, complexes bipyridine, 1,10-phenanthroline, dimethylimidazole, and pyrazole, possess the highest antibacterial activity. Antifungal activity was done by disc-diffusion assay and 50% inhibitory concentrations that possess high antifungal activity.

The increased demand for microbial originated Industrial enzymes especially lipases which have received least priority till last one and half decades and gained lots of importance in recent days owing to their applications in wide variety of fields such as food, dairy, pharmaceutical, detergent, textile, oleo-chemical, perfume and cosmetic industries etc., has lead to the identification of novel enzymes from new sources with unique properties. The present review mainly focuses on various currently available screening methods for identification of lipase producers.

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A series of mixed-ligand ruthenium(II) complexes of the type [Ru(en)(2)bpy](2+) (bpy=2,2-bipyridine; 1), [Ru(en)(2)phen](2+) (phen=1,10-phenantroline; 2), [Ru(en)(2)IP](2+) (IP=imidazo[4,5-f][1,10]phenanthroline; 3), and [Ru(en)(2)PIP](2+) (PIP=2-phenylimidazo[4,5-f][1,10]phenanthroline; 4) have been isolated and characterized by UV/VIS, IR, and (1)H-NMR spectral methods. The binding of the complexes with calf thymus DNA has been investigated by absorption, emission spectroscopy, viscosity measurements, DNA melting, and DNA photo-cleavage. The spectroscopic studies together with viscosity measurements and DNA melting studies support that complexes 1 and 2 bind to CT DNA (=calf thymus DNA) by groove mode. Complex 2 binds more avidly to CT DNA than complex 1, complexes 3 and 4 bind to CT DNA by intercalation mode, 4 binds more avidly to CT DNA than 3. Noticeably, the four complexes have been found to be efficient photosensitisers for strand scissions in plasmid DNA.

The new ligand 4-(isopropylbenzaldehyde)imidazo[4,5-f ][1,10]phenanthroline (ippip) and its complexes [Ru(phen)(2)(ippip)](2+)(1),[Co(phen)(2)(ippip)](3+)(2),[Ru(bpy)(2)(ippip)](2+)(3),[Co(bpy)(2)(ippip)](3+)(4)(bpy=2,2-bipyridine) and (phen=1,10-phenanthroline) were synthesized and characterized by ES(+)-MS, (1)H and (13)C NMR. The DNA binding properties of the four complexes were investigated by different spectrophotometric methods and viscosity measurements. The results suggest that complexes bind to calf thymus DNA (CT-DNA) through intercalation. When irradiated at 365 nm, the complexes promote the photocleavage of pBR322 DNA, and complex 1 cleaves DNA more effectively than 2, 3, 4 complexes under comparable experimental conditions. Furthermore, photocleavage studies reveal that singlet oxygen ((1)O(2)) plays a significant role in the photocleavage.

To establish the relevance of the cell wall in metal ion transport, cobalt uptake was examined in Neurospora crassa. Cobalt taken up was largely surface bound (>90%), resulting in a release of calcium and magnesium. Surface-bound cobalt could not enter intracellular locations upon further incubation of mycelia in a metal-free medium. Saturation of the surface with one metal augured subsequent dose-dependent entry of a different metal into intracellular locations. In comparison with the cobalt-resistant mutant, the cobalt-sensitive strain of N. crassa bound less cobalt on the surface but with significant intracellular accumulation. Our results demonstrate the importance of the cell wall in metal transport, toxicity, and resistance in fungi.

The complex of cobalt(III) ethylenediamine was synthesized, isolated and characterized by UV-Vis, IR, and 1 H NMR spectral methods. The binding of the complex with calf thymus DNA was investigated by absorption and emission spectroscopy, viscosity measurements, DNA melting and DNA photocleavage. The spectroscopic studies together with the viscosity measurements and DNA melting studies indicated that the complex binds to calf thymus DNA in a nonintercalative mode. This complex is found to promote photocleavage of the DNA plasmid pBR322 and shows a cytotoxic effect against CHO cells.

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