(1S,3aR,4S,6aR)-1-(4-Hydr­oxy-3-methoxy­phen­yl)-4-(4-hydr­oxy-3-methyl­phen­yl)perhydro­furo[3,4-c]furan-3a,6a-diol hexa­hydrate

In the title compound, C₂₀H₂₂O₈·6H₂O, the asymmetric unit contains one half-mol­ecule with the other half generated by a crystallographic twofold axis of symmetry. It was extracted from the leaves of Prinsepia utilis Royle and displays powerful anti-oxidant activity.