Five new pregnane glycosides from Cynanchum taiwanianum.

Five new pregnane glycosides, taiwanosides A [1], B [2], C [3], D [4], and E [5], together with wilfosides C1N [6], C2N [7], M1N [8], and K1N [9], were isolated from the roots of Cynanchum taiwanianum. Their structures were determined on the basis of spectroscopic and chemical evidence.