Reactions of 26-iodopseudodiosgenin and 26-iodopseudodiosgenone with various nucleophiles and pharmacological activities of the products.

26-Iodopseudodiosgenin (8) and 26-iodopseudodiosgenone (9) were reacted with various nucleophiles (KSCN, KOCN, NaCN, NaN(3) and various amines) to give pseudodiosgenin derivatives (4, 12, 16-20, 26) and pseudodiosgenone derivatives (5, 13, 21-25, 27), respectively. The reactions of 8 and 9 with KOCN gave the elimination products (10) and (11), respectively. The reaction of 9 with NaCN gave 5alpha,26- (14) and 5beta,26-dicyanocholestan-3-one (15).

Preparations of vitamin D analogs, spirostanols and furostanols from diosgenin and their cytotoxic activities.

Vitamin D analogs 12 and 13 having a spiro ring in the side chain, various spirostanols 18-21, 26, 27, 29 and 37, and furostanols 34-36 having SCN and SeCN groups at the 26 position were prepared from diosgenin 1 via (20S,22R,25R)-spirost-1alpha,2alpha-epoxy-4,6-dien-3-one 19 as a key intermediate. The cytotoxic activities of these derivatives as well as 1 on scarcely P-gp-expressed HCT 116 cells and P-gp-overexpressed Hep G2 cells were examined by MTT assay. Furostanols 34 (IC(50) value: 4.

4'-O-Alkyaloenin derivatives and their sulfates directed toward overcoming multidrug resistance in tumor cells.

The cytotoxic effects on HCT 116, Hep G2 and HCT 116/VCR 100-1-1 cell lines of synthetic 4'-O-alkylaloenins (2-17), 4'-O-benzylaloenin (18) and 4'-O-allylaloenin (19) were examined by MTT assay, and compared with that of aloenin (1) isolated from Aloe arborescens Mill. Var. natalensis Berger which showed no marked effect (IC50 value: > 100 microM).