Steroidal compounds in the roots of Asclepias tuberosa were investigated and 17alpha-hydroxyandrosta-4,6,15-trien-3-one 17-O-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranoside, termed ascandroside, was isolated from the CHCl3-soluble fraction. Among five doubly-linked cardenolide glycosides,