Antioxidant and antimicrobial profile of a secondary metabolite of Pseudomonas aeruginosa: ESR and spectrophotometric method

Marine Pseudomonas is a potential provider of novel bioactive metabolites and currently emerged as an important source for natural products with unique chemical diversity. The aim of the present study was to evaluate antimicrobial and antioxidant potential of partially purified fraction III extracted as a secondary metabolite from Pseudomonas aeruginosa MTCC 5210 isolated from marine sediments of coastal Tamil Nadu, India. In the present study, the antioxidant property of fraction III was evaluated using spectrophotometric and alectron spin resonance (ESR) techniques. The results of these studies revealed, fraction III quenches 1,1-Diphenyl-2-picrylhydrazyl free radical (DPPH●), nitric oxide radical and superoxide radical at appreciable levels. The ESR measurements show the reduction in peak intensities of DPPH● and nitric oxide radical after the addition of fraction III. It was also observed that quenching and reduction in peak intensities of standard free radicals studied are in proportion to the concentrations of fraction III studied. The antimicrobial activity of fraction III was evaluated using antibiotic resistant microbes such as methicillin resistant Staphylococcus aureus (MRSA). Since there is a constant demand for the natural antioxidants, the results of our present study suggest, that fraction III may act as a potential antioxidant and antibacterial compound.