Structure of aureobasidin a

Abstract

Aureobasidin A, a new antifungal antibiotic, was isolated from the culture medium of Aureobasidium pullulans R106. Aureobasidin A was a cyclic depsipeptide consisting of eight α-amino acid units and one hydroxy acid unit. The structures of the units were found by acid hydrolysis of the antibiotic to be 2(R)-hydroxy-3(R)-methylpentanoic acid, β-hydroxy-N-methyl-l-valine, N-methyl-l-valine, l-proline, allo-l-isoleucine, N-methyl-l-phenylalamne, l-leucine, and l-phenyl-alanine. The sequence of the units was identified by NMR and FAB-MS of the products from the alkaline hydrolysis of aureobasidin A. © 1991, JAPAN ANTIBIOTICS RESEARCH ASSOCIATION. All rights reserved.