ANDRIMID AND MOIRAMIDES AC, METABOLITES PRODUCED IN CULTURE BY A MARINE ISOLATE OF THE BACTERIUM PSEUDOMONAS-FLUORESCENS - STRUCTURE ELUCIDATION AND BIOSYNTHESIS

Andrimid (1) and moiramides A-C (2-4) have been isolated from solid ag ar cultures of a marine isolate of the bacterium Pseudomonas fluoresce ns. The chemical structures of moiramides A-C (2-4) have been elucidat ed by analysis of spectroscopic data. Andrimid (1) and moiramide B (3) were found to exhibit potent in vitro inhibition of methicillin resis tant Staphylococcus aureus. Stable isotope incorporation experiments h ave been used to elucidate the biogenesis of the acylsuccinimide fragm ent of andrimid (1) that is essential for antimicrobial activity. Thes e experiments demonstrated that the acylsuccinimide fragment is derive d from a combination of acetate and amino acid building blocks. It has been proposed that the biosynthesis proceeds through a dipeptide-like intermediate formed from gamma-amino-beta-keto acids that are in turn formed from valine and glycine homologated with acetate, presumably v ia malonyl-CoA.