Structure of a 3 alpha-(D-methylglycoside) of 7,8 beta-epoxysinogenin--a cardioactive steroid

C30H42O10, Mr = 562.66, orthorhombic, P2(1)2(1)2(1), a = 10.125 (1), b = 15.632 (2), c = 36.115 (4) A, V = 5716 (1) A3, Z = 8, Dm = 1.312 (2) (flotation), D chi = 1.308 g cm-3, Cu K alpha(lambda = 1.5418 A), mu = 7.18 cm-1, F(000) = 2416, T = 295 K. Final R(F) = 0.07 for 3348 significant reflections with I greater than or equal to 2.5 sigma(I). The A, B, C, D rings of the aglycone ring are found to be in cis-trans-cis fashion forming a buckled structure. The lactone is in C17 beta conformation. The molecules are stabilized by intermolecular hydrogen bonds. The longest direction of the steroid molecule is nearly parallel to the a axis. The conformational features exhibited by the molecule support proposals on activity.