4',5-Dihy-droxy-7-meth-oxy-flavanone dihydrate

Acta Crystallogr Sect E Struct Rep Online. 2012 Jan;68(Pt 1):o32-3. doi: 10.1107/S1600536811051221. Epub 2011 Dec 7.

Abstract

The title compound, C(16)H(14)O(5)·2H(2)O [systematic name: 5-hy-droxy-2-(4-hy-droxy-phen-yl)-7-meth-oxy-chroman-4-one dihydrate], is a natural phytoalexin flavone isolated from the native chilean species Heliotropium taltalense and crystallizes with an organic mol-ecule and two water mol-ecules in the asymmetric unit. The 5-hy-droxy group forms a strong intra-molecular hydrogen bond with the carbonyl group, resulting in a six-membered ring. In the crystal, the components are linked by O-H⋯O hydrogen bonds, forming a three-dimensional network. The 4-hy-droxy-phenyl benzene ring is bonded equatorially to the pyrone ring, which adopts a slightly distorted sofa conformation. The title compound is the hydrated form of a previously reported structure [Shoja (1990 ▶). Acta Cryst. C46, 1969-1971]. There are only slight variations in the mol-ecular geometry between the two compounds.