Kiyoshi Hamano

Schizostatin, a potent squalene synthase inhibitor from Schizophyllum commune: Isolation, structure elucidation, and total synthesis

Abstract The novel schizostatin ( 1 ) has been isolated as a potent inhibitor of squalene synthase. Its structure elucidation and total synthesis are described. Synthesis of the Z-isomer 12 and its biological activity are also reported.

Recovery of degenerate schizostatin production by screening single-basidiospore isolates in Schizophyllum commune

To recover degenerate schizostatin production in aSchizophyllum commune isolate, SANK 17785, we examined schizostatin production of 30 single-basidiospore isolates obtained from a basidiocarp of SANK 17785. One of the isolates showed high productivity (136–154 μg/ml) and maintained its high productivity for 26 mo. To explore other isolates with high schizostatin production, 76 single-basidiospore isolates from 7 wild basidiocarps were obtained and their schizostatin production was quantified. Four of the isolates produced more schizostatin than SANK 17785 did originally.

Discovery of dicephalosterol, a new testosterone 5α-reductase inhibitor, and some new mycological aspects of its producer,Dicephalospora rufocornea (sclerotiniaceae, discomycetes)

Dicephalosterol, a new testosterone 5α-reductase inhibitor, was found from isolates ofDicephalospora rufocornea, a sclerotiniaceous discomycete widely distributed, but not previously cultured. Under SEM observation, the polar appendage of the ascospores inD. rufocornea was found to be more solid than was hitherto reported. Dicephalosterol was produced by submerged fermentation for 7 d. This new analogue of testosterone showed an IC50 of 5.7 μg/ml for rat prostatic 5α-reductase, but no antimicrobial activity against bacteria or fungi.