(E)-1-(2-Hy-droxy-4,6-dimeth-oxy-phen-yl)-3-(4-meth-oxy-phen-yl)prop-2-en-1-one from Kaempferia rotunda Val.

The planar -CH=CHC(=O)- fragment (r.m.s. deviation = 0.074 Å) in the title compound, C(18)H(18)O(5), connects the planar hy-droxy-dimeth-oxy-phenyl (r.m.s. deviation = 0.039 Å) and meth-oxy-lphenyl (r.m.s. deviation = 0.021 Å) parts. The central fragment forms a dihedral angle of 13.7 (1)° with the hy-droxy-dimeth-oxy-phenyl part and 32.0 (1)° with the meth-oxy-phenyl part. The hy-droxy group forms an intra-molecular hydrogen bond to the carbonyl O atom.

[1R-(1α,2α,4α,5ß,6α,7α)]-4-Benzoyl-oxymethyl-5,6-dihy-droxy-3,8-dioxa-tricyclo-[5.1.0.0]octan-5-yl acetate (3-deacetyl-crotepoxide) from Kaempferia rotunda Val.

The title compound, C(16)H(16)O(7), isolated from Kaempferia rotunda rhizomes, features a six-membered cyclo-hexane ring that adopts a twisted-boat conformation owing to the presence of two adjacent epoxide attachments that lock in four of the six axial positions. The CH(3)CO(2)- and HO- substituents occupy equatorial positions. However, the bond angles at the ring carbon connected to the C(6)H(5)CO(2)CH(2)- substituent deviate signifcantly from the idealized tetra-hedral angles as the carbon atom is part of an epoxide ring. In the crystal, the molecules are linked into chains by O-H⋯O hydrogen bonds.