(18'.alpha.)-4'-Deoxyvincaleukoblastine 1H-Indolizino[8,1-cd]carbazole, vincaleukoblastine deriv. 2H-3,7-Methanoazacycloundecino[5,4-b]indole, vincaleukoblastine deriv. 4'-Deoxyvincaleukoblastine 57194-39-5 NSC250834 Vincaleukoblastine, 4'-deoxy- Vincaleukoblastine, 4'-deoxy-, (18'.alpha.)-