Santal monohydrate, an isoflavone isolated fromWyethia mollis

Abstract

The title compound [systematic name: 3-(3,4-dihydroxyphenyl)-5-hydroxy-7-methoxy-4H-chromen-4-one monohydrate], C16H12O6·H2O, is a monohydrate of a natural product santal isolated fromWyethia mollis. In the santal molecule, the dihedral angle between the benzoquinone and dihydroxyphenyl fragments is 53.9 (1)° and an intramolecular O—H...O hydrogen bond occurs. In the crystal, O—H...O hydrogen bonds link the components into corrugated layers parallel to theacplane. The short distance of 3.474 (5) Å between the centroids of the benzene rings in neighbouring santal molecules reveals then existence of π–π interactions within the layers.