12 新規抗真菌抗生物質オーレオバシジン類の構造(口頭発表の部)

概要

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Aureobasidins, new antifungal antibiotics, were isolated from the culture medium of Aureobasidium pullulans No. R106. We isolated 18 of these antibiotics and named them aureobasidins A〜R (1-18). All aureobasidins were cyclic depsipeptides consisting of eight of α-amino acid units and one hydroxy acid unit. The molecular formula of 1 was found to be as C_<50>H_<92>N_8O_<11> by elemental analysis and HRFAB-MS. The amino acids isolated from the acid hydrolysate of 1 were β-hydroxy-N-methylvaline, N-methylvaline, proline, alloisoleucine, N-methylphenylalanine, leucine, and phenylalanine. The hydroxy acid was 2-hydroxy-3-methylpentanoic acid. Mild alkaline hydrolysis of 1 gave 1a and 1b. The acid hydrolysate of 1a gave sarcosine instead of the β-hydroxy-N-methylvaline in the hydrolysate of 1. The sequence of the hydroxy acid and amino acids of 1a, which was a linear chain peptide, was found by NMR and FAB-MS. Compound 1b was found to have 2,3-didehydro-N-methylvaline replacing the β-hydroxy-N-methylvaline in 1. From those results, the structure of 1 was identified. The structures of 2〜18 were also examined.
天然有機化合物討論会の論文
1990-09-25