Investigation of antimicrobial activities of nonanoic acid derivatives

In a search for promising antimicrobial compounds, seven derivatives of methyl-branched n-nonanoic acid (MNA) at positions 2, 3, 4, 5, 6, 7, and 8 have been synthesized, and antimicrobial activity is described. Anti-microbial activities were determined by using disk diffusion tests and expressed as MIC values for the n-nonanoic acid using the microdilution broth method in vitro against Bacillus subtilis, Mycobacterium smegmatis, Sarcina lutea, Escherichia coli, Salmonella typhimurium and Streptomyces nojiriensis for bacteria, and Candida utilis for fungi, and compared with Penicillin G and Polymyxin B. All compounds exhibit varied antimicrobial activity against Gram-positive bacteria, but remarkable inhibitory effects were observed against C. utilis and S. lutea in two compounds (2-MNA and 5-MNA). Interestingly, only 4-MNA, 7-MNA and 8-MNA possess activity against Streptomyces.