Studies on the constituents of asclepiadaceae plant—LVII : The structures of six glycosides, wilfoside c1n, c2n, c3n, c1g, c2g and c3g, with novel sugar chain containing a pair of optically isomeric sugars

Abstract

Six new glycosides named wilfoside C3N ( l), C1N ( 2), C2N ( 3), C3G ( 4), C1G ( 5) and C2G ( 6) were isolated from Cynanchum wilfordi hemsley (Asclepiadaceae) and their structures were deduced on the basis of the chemical and spectral evidence. It is quite unusual that 2, 3, 5 and 6 include both D-cymarose and L-cymarose in each sugar chain.