Studies On The Constituents And Bioactivity Of Cynanchum Forrestii Studies On The ESI-MS Fragmentation Behavior Of Steroidal Glycosides From Cynanchum Forrestii

Cynanchum forrestii Schlechter (Asclepiadaceae) belongs to the genus Cynanchum in the family Asclepiadaceae. Cynanchum forrestii is widely distributed in Yunnan, Tibet, Gansu, Sichuan, Guizhou Provinces, etc, in China and its roots have been used as an antifebrile, diuretic and analgetic in China. Two species, Cynanchum atratum and Cynanchum versicolor as a traditional Chinese medicine "Pai-Wei" are similar in appearance with it. Cynanchum forrestii has been used as the substitute for the medicine "Pai-Wei" in some regions.In our investigations, the ethanol extraction exhibited cytotoxic activity; the EtOAc part and the fractions 3, 5, and 9 of the CHCl₃ part exhibited inhibition activities against MAO; the CHCl₃ part exhibited significant anti-inflammatory activity. Sixteen new steroidal glycosides, including ten 13, 14: 14, 15-disecopregnane-type glycosides and five 14, 15-secopregnane-type glycosides with the sugar parts usually consisting of 5 or 6 sugar units, in which inner deoxysugar ones and outer 2 glucose units with 1→4 or 1→6 linkage modes, one normal pregnane glycoside, and one new 3, 4-seco-13, 27-cyclo-triterpene, together with eleven known compounds were isolated from the ethanol extract of the roots of Cynanchum forrestii for the first time. Their structures were established as compound 1 glaucogenin C 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-( 1→4)-β-D-oleandropyranosyl-( 1 →4)-β-D-digitoxopyrano-syl-(1→4)-β-D-oleandropyranoside, compound 2 glaucogenin C 3-O-β-D-glucopyranosyl-( 1→4)-β-D-glucopyranosyl-( 1→4)-α-L-cymaropyranosyl-( 1→4)-β-D-digitoxopyranosyl-(1→4)-β-D-oleandropyranoside, compound 3 glaucogenin C 3-O-β-D-glucopyranosyl-( 1 →4)-β-D-glucopyranosyl-( 1→4)-α-L-cymaropyranosyl-( 1→4)-β-L-cymaropyranosyl-(1→4)-β-D-oleandropyranoside, compound 4 glaucogenin C 3-O-β-D-glucopyranosyl-( 1 →6)-β-D-glucopyranosyl-( 1→4)-β-D-oleandropyranosyl-( 1 →4)-β-D-digitoxopyranosyl-(1→4)-β-D-oleandropyranoside, compound 5 glaucogenin C 3-O-β-D-glucopyranosyl-( 1 →6)-β-D-glucopyranosyl-( 1 →4)-β-D-oleandropyranosyl-...