Diarylheptanoids from the Rhizomes of Curcuma xanthorrhiza and Alpinia officinarum

Five diarylheptanoids including two new compounds were isolated from the rhizomes of Curcuma xanthorrhiza (Zingiberaceae). The structures of the new compounds were determined to be octahydrocurcumin ((3S, 5S) -1, 7-bis (4-hydroxy-3-methoxyphenyl) -heptane-3, 5-diol) (Ia) and (1ξ) -1-hydroxy-1, 7-bis (4-hydroxy-3-methoxyphenyl) -6-heptene-3, 5-dione (II) on the basis of spectral and chemical evidence. The absolute configurations of Ia and a new similar diarylheptanoid, (3R, 5R) -1- (4-hydroxyphenyl) -7-phenylheptane-3, 5-diol (VIa), isolated from the rhizomes of Alpinia officinarum (Zingiberaceae), were established by application of the exciton chirality rule.