77(PB2-7) 糸状菌Penicillium paxilliの生産する新規ステロールUCY-1003の構造決定(ポスター発表の部)

概要

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A unique 18-oxidized cholestane structure of UCY-1003 produced by Penicillium paxilli KAC-1843 was determined as 1 on the basis of chemical and spectroscopic evidence. ^1H and ^<13>C NMR implied 1 had a cholestan-3-β-ol structure carrying three functional groups, one tri-substituted epoxide group, one acetal function and one exo-methylene group. C-24 exo-methylene of 1 was characterized by the observation of a long range coupling between H-28a and H-25 and a NOE between H-28a and terminal methyls in its ^1H NMR, as well as the EI-mass fragment on C-20 side chain. Jone's oxidation of 1 led to the diketocarboxylic acid(9), which exhibited characteristic mass peaks at m/z 454, 426, 168 and 123 indicating the position of the epoxide group to be at C-7,8. The location of the acetal group at O-20〜C-18〜O-15 was evidenced by the observation of a long range coupling between H-18 and C-20 in the COLOC spectrum and the NOE between H-7 and H-15. The structures of acetal migration products of 1 (5, 6, 10) also assisted this location. The connectivity of the all carbons including three functional groups of 1 was confirmed by the 2D-INADEQUATE spectrum of 1. The absolute configulation of C-20 was defined as S by the observation of NOE from 20-CH_3 to 12-βH and the positive cotton effect in the CD spectrum of 3-keto derivative, 11.
天然有機化合物討論会の論文
1987-07-25