Pregnane glycosides from the roots of Asclepias tuberosa.

Sixteen glycosides of pregnanes, including ikemagenin, lineolon, and a new pregnane, 3beta8beta,14beta,15beta,16alpha-pentahydroxy-++ +5alpha-pregnan-20-one, termed pleurogenin, were isolated from the roots of Asclepias tuberosa. Among ikemagenin and lineolon glycosides, one (1) was a known glycoside, and eight (2-7, 10, 13) were glycosides with new combinations of ikemagenin or lineolon and known sugar sequences composed of D-cymarose, D-oleandrose, D-thevetose and D-glucose. The structures of four new glycosides of ikemagenin (8, 9, 11, 12) and three of pleurogenin (14-16) were determined. The new glycosides have sugar sequences ranging from tetraoside to heptaosides.