1-(3,4-Dimethoxyphenyl)propan-1-one

The title compound, C11H14O3, was isolated from the stems of Trigonostemon xyphophylloides, which belongs to Trigonostemon genus of Euphorbiaceae. The plants in this genus were used in folk medicine, such as for the treatment of diseases caused by viruses and fungi. The limited investigation of the chemistry of this plant prompted an examination of constituents of its twigs, from which the title compound was isolated. The molecule is approximately planar with an r.m.s. deviation of 0.1237Å. In the crystal, intermolecular C—H⋯O hydrogen bonds connect the molecules into a two-dimensional network structure with an R 2 2(12) graph-set motif.

The title compound, C 11 H 14 O 3 , was isolated from the stems of Trigonostemon xyphophylloides, which belongs to Trigonostemon genus of Euphorbiaceae. The plants in this genus were used in folk medicine, such as for the treatment of diseases caused by viruses and fungi. The limited investigation of the chemistry of this plant prompted an examination of constituents of its twigs, from which the title compound was isolated. The molecule is approximately planar with an r.m.s. deviation of 0.1237Å . In the crystal, intermolecular C-HÁ Á ÁO hydrogen bonds connect the molecules into a two-dimensional network structure with an R 2 2 (12) graph-set motif.

Comment
The title compound was isolated from plants such as Pteronia camphorata (Zdero et al., 1990) and Virola surinamensis (Lopes et al., 1996). In our ongoing studies of natural products with biological activity we isolated the compound from the 75% EtOH extract of the stems of Trigonostemon xyphophylloides, a plant used as a folk medicine which were collected from Jianfengling County, Hainan Province, P.R. China. We have undertaken the X-ray crystal structure analysis of the title compound in order to establish its molecular structure and relative stereochemistry.

Experimental
Air-dried stems of Trigonostemon xyphophylloides (5.9 kg) were ground and percolated (3 × 2.5 h) with 75% EtOH at 60°C, which was suspended in 1.5 L water and then partitioned with petroleum ether, chloroform, ethyl acetate and n-BuOH, successively, yielding a petroleum ether extract, a chloroform extract, an ethyl acetate extract and a n-BuOH extract, respectively. The petroleum ether extract was subjected to a silica gel CC column using petroleum ether as first eluent and then increasing the polarity with EtOAc, to afford 20 fractions (A-T). Fraction D was further separated by column chromatography with a gradient of petroleum ether-EtOAc to give the title compound. The crude product was dissolved in small amount of ethyl acetate to obtain single crystals suitable for X-ray analysis by slow evaporation of ethyl acetate solution at 298 K.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.