87532-26-1 9.beta.,10.beta.-Epoxyroridin H EPOXYRORIDIN H NSC339661 RORIDIN H, 9B, 10B EPOXY- Verrucarin A, 2',3'-didehydro-7'-deoxo-2'-deoxy-9,10-epoxy-7',5'-(ethylidenoxy)-, (2'E,9R,10S)-