Antifungal stilbenoids from Stemona japonica.

Three new dihydrostilbenes, stilbostemins P-R (1-3), and a new dihydrophenanthrene, stemanthrene G (4), were isolated from the roots of Stemona japonica together with three known bibenzyls, 3,5-dihydroxy-2'-methoxy bibenzyl (5), 3,3'-dihydroxy-2,5'-dimethoxy bibenzyl (6), and 3,5,2'-trihydroxy-4-methyl bibenzyl (7). Their structures were elucidated by spectroscopic analyses. Compounds 5 and 6 exhibited strong antifungal activities against Candida albicans.