|Budget Amount *help
¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1990 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1989 : ¥1,500,000 (Direct Cost : ¥1,500,000)
The cell wall of plant pathogenic fungi Phytophthora is mainly composed of highly branched beta-(1,3) glucan. We realized that this typical cell wall composition should be useful to investigate the inhibitor of beta-(1.3) glucan synthesis. The culture filtrates derived from fungi were screened with the objective of detecting any morphological change that might be occurring in hyphae. On the basis of our screening, Acremonium strictum were found to produce an active compound which induced highly branched and noded hyphae to P. capsici. A yellow colored compound was isolated from the culture filtrate of A. strictum and its molecular formula was determined by HR-FABMS as C_<28>H_<32>O_9. From the analyses of proton NMR, carbon NMR, cosy spectrum and HMBC spectrum, this compound was revealed to be identical to bisvertinolone, however, we revised the stereo structure. Using NOE experiment and CD spectrum, we determined the absolute stereochemistry of this compound. This compound showed strong activity in vivo (10 mug/disc), however it showed weak inhibitory activity in vitro (400 mug/ml) using rabeled UDP-glucose and beta-(1,3) glucan synthetase prepared from baker's yeast. Therefore, we are now investigating the inhibitory activity to beta-(1,6) glucan synthesis.