Isolation and Characterization of the Anticancer Compound Piceatannol from Sophora Interrupta Bedd.

BACKGROUND

Sophora belongs to the family of Fabaceae and the species in this genus are currently used as a folklore medicine for preventing a variety of ailments including cancer. Our aim was to identify and validate an anticancer compound from Sophora interrupta using multi-spectroscopic, anticancer screening, and molecular docking approach.

METHODS

The cytotoxicity of the various solvent extracts, petroleum ether, n-butanol, and ethyl acetate (EtOAc) of the S. interrupta root powder was evaluated in a breast cancer cell lines (MCF-7). The extract that had anticancer activity was subjected to column chromatography based on the polarity of the solvents. The anticancer activity of the elution fractions was validated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The isolated metabolite fraction with anticancer activity was run through a C18 column isocratic and gradient high-performance liquid chromatography (HPLC). The structure of the isolated compound was characterized using (1)H nuclear magnetic resonance (NMR), (13)C-NMR, Fourier transform infrared spectroscopy, and liquid chromatography-mass spectrometer methods.

RESULTS

The crude EtAOc extract effectively inhibited the proliferation of MCF-7 cells. The column eluted chloroform and EtOAc (4:6) fraction of the EtOAc extract showed significant anticancer activity in the MCF-7 cells compared with normal mesenchymal stem cells. This fraction showed three major peaks in the HPLC chromatogram and the first major peak with a retention time (RT) of 7.153 was purified using preparative-HPLC. The structure of the compound is a piceatannol, which is a metabolic product of resveratrol. Piceatannol formed direct two hydrogen bond interactions between Cys912 (2H), and Glu878 of vascular endothelial growth factor receptor 1 (VEGFR1) with a glide-score (G-score) of -10.193, and two hydrogen bond interactions between Cys919, and Asp1046 of VEGFR2, with a G-score of -8.359. The structure is similar to that of the crystallized protein for VEGFR1 and R2.

CONCLUSIONS

Piceatannol is a secondary metabolite of S. interrupta that has anticancer activity. Moreover, piceatannol has been isolated for the first time from S. interrupta.