Amiclenomycin Peptides ‐ Isolation and Structure Elucidation of New Biotin Antimetabolites

Six peptide antibiotics were isolated from the culture filtrate of Streptomyces venezuelae Tü 2460. The 4‐amino‐2,5‐cyclohexadienyl ring of the amino acid amiclenomycin (Acm, 7) was found to be the essential structural element of the three dipeptides L‐MeIle‐L‐Acm (1, stravidin S3), L‐Ile‐L‐Acm (2), and L‐MeVal‐L‐Acm (3, stravidin S2) as well as the three tripeptides L‐MeIle‐L‐Acm‐L‐Gln (4), L‐Ile‐L‐Acm‐L‐Gln (5) and L‐Val‐L‐Acm‐L‐Gln (6). In addition L‐amiclenomycin (7) and L‐Acm‐L‐Gln (8) were obtained by enzymatic cleavage with pronase P. All eight antibiotics inhibit the growth of gram‐negative bacteria by blocking the biotin biosynthesis. A synergistic enhancement of the antibiotic action was found by a polypeptide L (9) also isolated from S. Venezuelae Tü 2460. Further screening Supplemented on correction(Nov. 7,1985). revealed, that the S. Venezuelae strain Tü 2605 produces the antibiotic L‐MeIle‐L‐Acm‐L‐Glu (10).