Three new C21 steroidal glycosides from Tylophora atrofolliculata

Abstract The Asclepiadaceae plant is a rich source of C21 steroidal glycosides. The present study aimed to investigate the C21 steroidal glycosides from the whole plants of Tylophora atrofolliculata (Asclepiadaceae). As a result, three new C21 steroidal glycosides named atrofollicosides A-C (1-3) and four known steroidal glycosides (4-7) were isolated. The structures of these compounds were characterized using NMR spectroscopy. Highlighted here is a new disecopregnane-type steroid with a hydroxyl group at the C-18 position that constitutes the aglycone of compound 1.