title: Brasilixanthone.
abstract: THE TITLE XANTHONE [SYSTEMATIC NAME: 5,13-dihy-droxy-3,3,10,10-tetra-methyl-3H-dipyrano[3,2-a:2',3'-i]xanthen-14(10H)-one], C(23)H(20)O(6), was isolated from the roots of Cratoxylum formosum ssp. pruniflorum. There are two mol-ecules (A and B) in the asymmetric unit, which show chemical but not crystallographic inversion symmetry. The xanthone skeleton in both mol-ecules is approximately planar, with an r.m.s. deviation of 0.0326 (9) Å for mol-ecule A and 0.0355 (9) Å for mol-ecule B from the plane through the 14 non-H atoms. The pyran rings in both mol-ecules adopt sofa conformations. Intra-molecular O-H⋯O hydrogen bonds generate S(5) and S(6) ring motifs. Viewed onto the bc plane, the crystal structure resembles a herringbone pattern. Stacks of mol-ecules are stabilized by π-π inter-actions with centroid-centroid distances of 3.600 (5) Å. The crystal structure is further stabilized by weak C-H⋯O and C-H⋯π inter-actions.
authors: Suchada
authors: S
authors: Chantrapromma
authors: Nawong
authors: N
authors: Boonnak
authors: Hoong-Kun
authors: HK
authors: Fun
authors: Chatchanok
authors: C
authors: Karalai
authors: Kan
authors: K
authors: Chantrapromma
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