Received 16 January 2013
The title compound, C18H16O8, was isolated from the plant Artemisia baldshuanica Krasch et Zarp. The molecule is approximately planar, with the exception of the terminal methyl groups, the C atoms of which devitate from their attached ring planes by 1.243 (5) and 1.168 (5) Å. The dihedral angle between the substituted benzopyran and benzene rings is 5.8 (1)°; this near planarity could be due to conjugation or a packing effect. Intramolecular O-HO and C-HO hydrogen bonds occur. In the crystal, molecules are connected by O-HO hydrogen bonds involving the hydroxy and carbonyl groups, forming hydrogen-bonded chains along  and [1-10]. The chains are linked by C-HO interactions.
For the biological activity of flavonoids, see: Bodewes et al. (2011); Veitch & Grayer (2011). For related structures, see: Martinez-Vazquez et al. (1993).
Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: ZP2001 ).
We thank the Academy of Sciences of the Republic of Uzbekistan for supporting this study (grant No. FA-F7-T185)
Bodewes, T. C. F., Luttikhold, J., van Stijn, M. F. M., Visser, M., van Norren, K., Vermeulen, M. A. R. & van Leeuwen, P. A. M. (2011). Curr. Org. Chem. 15, 2616-2626.
Martinez-Vazquez, M., Vazquez Garcia, H. M., Toscano, R. A. & Perez, G. E. (1993). J. Nat. Prod. 56, 1410-1415.
Oxford Diffraction (2009). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Veitch, N. C. & Grayer, R. J. (2011). Nat. Prod. Rep. 28, 626-1695.
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.