Synthesis, Isolation of Phenazine Derivatives and Their Antimicrobial Activities

Abstract

Antimicrobial activity of natural phenazine-1-carboxylic acid (PCA) from Pseudomonas aeruginosa TISTR 781 and synthetic phenazine-5,10-dioxide (PDO), prepared by oxidation of the phenazine, were evaluated by in vitro disc diffusion and minimal inhibitory concentration (MIC) methods. The results indicated that both phenazine derivatives differed clearly in their antimicrobial activity. PCA showed better efficacy against growth of Acidovorax avenae subsp. citrulli, Bacillus subtilis, Candida albicans, Escherichia coli and Xanthomonas campestris pv. vesicatoria than PDO at low concentrations of PCA (MIC; 17.44 - 34.87 ppm) as an antimicrobial agent. In contrast, PDO acted as a stronger inhibitor than PCA when tested against Pseudomonas syringae and Enterobacter aerogenes. The last bacterial strain, Ralstonia solanacearum, can be suppressed by the same concentration of PCA and PDO (MIC; 62.50 ppm). The data provided beneficial information for choosing phenazine types to inhibit some general strains and plant pathogenic bacteria