Antimicrobial and genotoxic activity of novel ruthenium(III) complex with n-phenyl-5-nitrosalicylideneimine

In this study, novel hexa coordinated ruthenium(III) complex of the type Na[RuCl2L2)] (where L = monobasic bidentate Schiff base derived from the condensation of 5-nitrosalicyladehyde with aniline) has been synthesized and characterized by electrospray ionization time-of-flight mass spectrometry, infrared spectroscopy and ultraviolet/visible spectrophotometry. Schiff base N-phenyl-5-nitrosalicylideneimine is coordinated to the ruthenium via imine nitrogen and phenolic oxygen. Mass spectra showed molecular ion (M-) at m/z 653.9641 which corresponds to [C26H18Cl2N4O6Ru]-. The in vitro antimicrobial properties of the Schiff base and the complex were tested by micro-dilution technique and agar plate assay for determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The compounds showed a higher antibacterial activity against tested Gram-positive bacteria (Staphylococcus aureus ATCC 33591 and ATCC 29213), whereas against the Gram-negative bacteria (Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 700603) were ineffective. The genotoxic effects of Ru(III) complex were investigated using the Cytokinesis Block Micronucleus (CBMN) assay in human lymphocytes cultures. The cell culture treated with the complex at a concentration of 3.7 µg/mL exhibit the most prominent effect of decreasing the frequency of micronucleus for 44%, while at the concentrations of 1.5 and 7.4 µg/mL effect is slightly lower (40%), compared to the control cell culture

Expression and characterization of human interferon-beta I in the methylotrophic yeast Pichia pastoris

We describe the heterologous expression of a human interferon-beta1 in the methylotrophic yeast Pichia pastoris. Biologically active recombinant human interferon-beta1 (rHulFN-beta1) was secreted from shake-flask-grown P pastoris cells into the medium using the Saccharomyces cerevisiae alpha-mating factor prepro-leader sequence at the level of (1-3) x 10(5) i.u. (international units)/ml (6-12 mg/litre). An rHulFN-beta1 with an N-terminal sequence identical with that of native HulFN-beta1 was purified and the specific activity was determined (2-3 x 10(7) i.u./mg). It was found that the secreted recombinant protein was partially N-glycosylated