Bioassay-guided fractionation of a hexane extract of the rhizomes of Curcuma xanthorrhiza Roxb. (Zingiberaceae) led to the isolation of three non-phenolic diarylheptanoids, identified mainly by high-field 1H-NMR as trans-trans-1,7-diphenyl-1,3-heptadien-4-one (alnustone),