P-11 殺虫性インドールアルカロイド、オカラミン類の新規関連化合物(ポスター発表の部)
詳細
During the course of searching for insecticidal compounds of microbial origin, we isolated Penicillium simplicissimum ATCC 90288 (formerly AK-40), which produced indole alkaloids, okaramines A (1) and B (2), as active principles. We also obtained okaramine C (3) from P. simplicissimum AHU 8402. Since okaramines have unique structures, we had an interest in the structure-activity relationships among okaramines and biogenesis of okaramines. We investigated minor metabolites in the fermentation products of okara (insoluble residue of whole soybean) with ATCC 90288, affoding three new congeners, 4, 5 and 6.4, named okaramine D, was revealed to be 12-hydroxyokaramine B. The structures of okaramine E (5) and okaramine F (6) were determined by spectroscopic methods. The LD_<50> value of 4 was 20μg/g diet. On the other hand, 5 and 6 showed no activity againt the larvae of silkworm, indicating that azetidine and pyrrolidine rings are very important for this activity. It is not revealed, however, which play more of an essential role in reducing activity, formation of the azetidine ring or hydroxylation at C-12.
