73341-73-8 C-14919 E-2 Geldanamycin, 18,21-didehydro-6,17-didemethoxy-18,21-dideoxo-18,21-dihydroxy-15-methoxy-6-methyl-11-O-methyl-, (6S,15R)- (9CI) Macbecin II NSC 330500