A new estra-1,3,5(10)-triene-3,17beta-diol solvate: estradiol-methanol-water (3/2/1)

The title solvate of the steroid 17beta-estradiol (E(2)) with methanol and water, C(18)H(24)O(2).0.67CH(4)O.0.33H(2)O, is the first E(2) derivative to contain three crystallographically independent molecules in the asymmetric unit. The three steroid molecules, along with two methanol molecules and a water molecule, create a three-dimensional hydrogen-bonded system. Three-sided columns are formed, with the estradiol molecules aligned lengthwise parallel to (101), and joined by solvent molecules at both hydrophilic ends. The three estradiol molecules differ slightly in their ring-bowing angles, i.e. the angle between the mean plane of the A ring and that of the BCD ring; this angle ranges from 7.1 to 12.2 degrees.