Studies On The Metabolism Of And The Signal Transduction Pathways Of Apoptosis Induced By The Constituents Of Dioscorea Pahthaica Prain

The medicinal plant Dioscorea panthaica Pram et Burkill (Dioscoreaceae) is widely distributed in Yunnan, Sichuan, Guizhou and Hunan provinces of P. R. China. Its rhizomes have been known in traditional Chinese medicine as saponin-rich herbal medicine used for the treatment of gastropathy, anthrax, rheumatic heart disease and rheumarthritis. It has been reported that steroidal saponins were the main active components. In the course of a screening program to evaluate Dioscorea panthaica as a source of new interesting bioactive compounds, 28 compounds were isolated from the rhizome of Dioscorea pant haica with porous resin (DlO 1), silica gel, sephadex LLi-20, polyamide, HPLC etc. Among them, 22 compounds were elucidated on the basis of physi-.chemical and spectral methods. The nine new compounds were named as dioscoreside A (26-0- P glucopyranosyl-3 P , 26-diol-20, 22-seco-25 (R)-furosta-5-en-20, 22-dione-3-0- U rhamnopyranosyl- (1 梸2) -[ P -D-glucopyranosyl- (1 梸-3) j- P -D-glucopyranoside (12), dioscoreside B (26-0- P -D-glucopyranosyl-3 P , 23 a , 26梩riol-20, 22-seco-25 (R)- furosta-5-en-20, 22-dione-3-0- a -L-rhamnopyranosyl- (1棐2) ~[a -L- rhamnopyranosyl- (1 棏4) ]- P -D-glucopyranoside (13), dioscoreside C (26-0- P -D-glucopyranosyl-3 P, 26-diol-23( a )-methoxyl-25 (R)-furosta-5, 20(22)-diene-3-0- a -L-rhamnopyranosyl- (1 梸 2) -[ a -L-rhamnopyranosyl- (1 棏4) j- P -D-glucopyranoside (14), dioscoreside D (26-0- P -D-glucopyranosyl-3 P, 26-diol-20, 22-seco-25 (R)-furosta-5-en-20, 22-dione-3-0- a - L-rhaninopyranosyl- (1 棏2) -[ a -L- rhamnopyranosyl- (1 棏4) ]- P -D-glucopyranoside (15), dioscoreside E (26-0- P -D-glucopyranosyl-3 P, 26-diol-25 (R)-furosta-5, 22 (23)-dien-20 (R)- methoxyl-3-0- a -L-rhamnopyranosyl- (1棐-2) ~[a -L- rbamnopyranosyl- (l棐4) II- P -D-glucopyranoside (16), dioscoreside F (26-0- P -D-glucopyranosyl-3 P , 20 (a ), 22, 23 (S), 26-pentaol-25 (R)-furosta-5-en-3-0- a -L-rhamnopyranosyl- (1 棏 2 ) -[ a -L- rhamnopyranosyl- (1 棏-4) ]- P -D-glucopyranoside) (17), dioscoreside G (26-0- P -D- glucopyranosyl-3 P. 17 a, 22, 26-tetraol-20, 22-seco-25 (R)-furosta-5-en-20-one-3-0- a - -6- ABSTRACT L-rhaninopyranosyl- (1 棏~2) -[ a -L- rhamnopyranosyl- (1 棏~4) ]- P -D-glucopyranoside (18), dioscoreside H (26-0- P -D-glucopyranosyl-3 P, 23, 26-triol-25 (R)-furosta-5, 20 (22)- diene-3-0- a -L-rhamnopyranosyl- (1 棏-2) -[ a -L- rhamnopyranosyl- (1 棏-4) ]- P -D- glucopyranoside (19), dioscoreside I (pregnadienolone 3-0- a -L- rhamnopyranosyl- (1 梸 2) -[ P -D-glucopyrnosyl- (1 棏-3)]- P -D-glucopyranoside) (20). They have novel carbon skeletons or new aglycones. The known compounds were identified as diosgenin (1), P - sitosterol (2), palinitic acid (3), stigmasterol (4), daucosterol (5), progenin 11(6), progenin III (7), dioscm (8), gracillin (9), 26-0- P -D-glucopyranosyl-25 (R)-furosta-5, 20 (22)-diene-3 P. 26-diol-3 -0-[ a -L-rhamnopyranosyl-( 1 梸 2)]- P -D-glucopyranosyl (10), pseudoprotodiscin (11), pregnadienolone 3-0- P -chacotrioside (21), protodioscin (22)~ Among them, 26-0- P - D- glucopyranosyl- 25 (R)- furosta- 5, 20 (22) -diene- 3 P, 26- did- 3-0 -[ a -L- rhamnopyranosyl-(1 棏- 2)]- P -D-glucopyranosyl (10), pseudoprotodiscin (11) and pregnadienolone 3-0- P -chacotrioside (21) were isolated from this genus for the first time. The investigation on the metabol...