CEPACIDINE-A, A NOVEL ANTIFUNGAL ANTIBIOTIC PRODUCED BY PSEUDOMONAS-CEPACIA .2. PHYSICOCHEMICAL PROPERTIES AND STRUCTURE ELUCIDATION

Cepacidine A is a novel glycopeptide with a potent antifungal activity , which is produced by Pseudomonas cepacia AF 2001. Its molecular weig ht was determined by FAB-MS (m/z 1215). The compound is comprised of g lycine (1), serine (2), 2,4-diaminobutyric acid (1), aspartic acid (1) , beta-hydroxy tyrosine (1), beta-hydroxy asparagine (1), xylose (1) a nd 5,7-dihydroxy-3,9-diaminooctadecanoic acid (1). Unfortunately, cepa cidine A is a mixture of A(1) and A(2), either of which is barely dist inguishable. Cepacidine A(2) includes asparagine (1) instead of beta-h ydroxy asparagine (1) of cepacidine A(1). The MS data and the NOESY, T OCSY and HMBC spectra show that cepacidine A is a cyclic peptide and x ylose is connected to 5,7-dihydroxy-3,9-diaminooctadecanoic acid.