title: 4,5,7,8,17-Penta-hydr-oxy-14,18-dimethyl-6-methyl-ene-3,10-dioxapenta-cyclo-[9.8.0.0.0.0]nona-dec-14-ene-9,16-dione methanol solvate dihydrate.
abstract: The title quassinoid compound, C(20)H(24)O(9)·CH(3)OH·2H(2)O, is a natural eurycomanone isolated from the roots of Eurycoma longifolia. The mol-ecules contain a fused five-ring system, with one tetra-hydro-furan ring adopting an envelope conformation, one tetra-hydro-pyran-2-one ring in a screw boat conformation, one cyclo-hexenone ring in a half-chair conformation and two cyclo-hexane rings in chair conformations. Intra-molecular C-H⋯O inter-actions generate S(5) ring motifs and an O-H⋯O inter-action generates an S(7) ring motif. In the crystal, mol-ecules are linked via inter-molecular O-H⋯O inter-actions along the b axis and further stacked along a axis. The absolute configuration of the title compound was inferred from previously solved structures of its analogues.
authors.forename: Chin Hoe
authors.initials: CH
authors.lastname: Teh
authors.forename: Siew Chin
authors.initials: SC
authors.lastname: Teoh
authors.forename: Chin Sing
authors.initials: CS
authors.lastname: Yeap
authors.forename: Kit Lam
authors.initials: KL
authors.lastname: Chan
authors.forename: Hoong-Kun
authors.initials: HK
authors.lastname: Fun