New cucuribitane saponin from Momordica charantia / 中草药

Objective To study the chemical constituents in Momordica charantia.Methods The alcohol extract was isolated by macroporous adsorption resin and silica gel,and the compound structures were identified by spectral methods.Results Two couple isomers were isolated,the structure of one couple was identified as 19R-5?,19-epoxycucurbita-6,23,25-trien-3?,19-diol(Ⅰa)and 19S-5?,19-epoxycucurbita-6,23,25-trien-3?,19-diol(Ⅰb);the structure of the other couple was identified as 3-O-glucopyranoside of 5?,19-epoxycucurbita-6,23,25-trien-3-ol(Ⅱa),and 3-O-allopyranoside of 5?,19-epoxycucurbita-6,23,25-trien-3-ol(Ⅱb).Conclusion New compounds Ⅰa,Ⅰb,Ⅱa,and Ⅱb are isolated from M.charantia for the first time.