The Penultimate Tyrosine Residues are Critical for the Genotoxic Effect of Human Hemoglobin.

Hemoglobin (Hb) is a potent oxidant outside the erythrocyte. The tyrosines α140 and ß145 play an important role in the structure and function of Hb by forming switch and hinge contacts. These carboxy-terminal residues of the alpha and beta chains, respectively, were replaced to phenylalanine and several different methods were used to characterize the obtained mutants including a comet and plasmid DNA cleavage assay. It was observed that the genotoxic effect was 40% higher for αY140F compared with the wildtype, the ßY145F and the double (αY140/ß145F) mutants as determined by the comet assay. Cleavage of purified plasmid DNA after Hb application also revealed that the αY140F mutant showed 2-fold higher activity, while the ßY145F and αY140/ß145F mutants reduced the activity compared to wildtype Hb. This study clearly indicates that the penultimate tyrosines are involved in the genotoxicity of Hb.

Facile preparation of tetrahydro-5H-pyrido[1,2,3-de]-1,4-benzoxazines via reductive cyclization of 2-(8-quinolinyloxy)ethanones and their antioxidant activity.

Pd/C-catalyzed reductive cyclization of 1-aryl-2-(8-quinolinyloxy)ethanones opens a facile access to the title compounds in good yields. The scope of this reductive cyclization is explored and the antioxidant activities of the products are studied.

Effective bioremoval and detoxification of textile dye mixture by Alishewanella sp. KMK6.

Alishewanella sp. strain KMK6 was able to degrade mixture of textile dyes (0.5-2.0 g l(-1)) within 8 h. An initial 28 % reduction in COD was observed immediately after decolorization at static anoxic conditions which on further incubation at shaking conditions reduced by 90 %. Partially purified azoreductase was able to utilize different azo dyes as substrates. The HPLC profile of dye degradation showed formation of metabolic products. Further FTIR analysis showed significant changes in the peaks corresponding to functional groups present in dye mixture and its degradation products. The genotoxicity assessment showed that the dye degradation products were non-toxic compared to dye mixture.

Synthesis and biological evaluation of novel 2,4,6-triazine derivatives as antimicrobial agents.

A series of 2,4,6-trisubstituted [1,3,5]triazines were synthesized and evaluated for their antimicrobial activity against two representative Gram-positive, Gram-negative bacteria and two fungi. Biological data revealed that among all the compounds screened, compounds 3f, 3g, 3h, 3i, 3m, 3o and 3p found to have promising antimicrobial activity against all the selected pathogenic bacteria and fungi. Out of the synthesized compounds seven analogues have shown MIC in the range of 6.25-12.5 µg/mL. These compounds were generally nontoxic and may prove useful as antimicrobial agents.

Decolorization and biodegradation of azo dye, reactive blue 59 by aerobic granules.

The present study deals with development of aerobic granules from textile wastewater sludge and challenged with different concentration of reactive blue 59 (RB59) to test their dye degradation potential. The granules efficiently degraded reactive blue 59 and also sustained higher dye loading of up to 5.0 g l(-1). The significant induction of enzymes azoreductase and cytochrome P-450 indicated their prominent role in the dye degradation while genotoxicity studies demonstrated that the biotransformed product of the dye as non-toxic. The microbial community of the textile dyes degrading aerobic sludge granules analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), revealed significantly diverse dye degrading microbial community belonging to alpha-, beta-, and gamma-proteobacteria.