Studies on chemical constituents of rhizomes of Sophora tonkinensis

Thirteen compounds were isolated from the 95% aqueous EtOH extract of the rhizomes of Sophora tonkinensis by a combination of various chromatographic techniques including column chromatography over silica gel, Sphadex LH-20, MCI, ODS, and semi-preparative HPLC.Their structures were elucidated as 1-(6,7-dihydro-5H-pyrrolo[1,2-a]imidazol-3-yl)ethanone(1), cyclo(Pro-Pro)(2), nicotinic acid(3), p-hydroxybenzonic acid(4), p-methoxybenzonic acid(5), 4-hydroxymethyl-2,6-dimethoxyphenol-1-O-β-D-glucopyranoside(6), coniferin(7), syringin(8),(-)-secoisolariciresinol-4-O-β-D-glucopyranoside(9),(-)-syringaresinol-4-O-β-D-glucopyranoside(10),(-)-syringaresinol-4,4'-di-O-β-D-glucopyranoside(11),(-)-pinoresinol-4,4'-di-O-β-D-glucopyranoside(12), and(6S,9R)-roseoside(13) by their physicochemical properties and spectroscopic data.Compound 1 was a new naturalproduct, and compounds 2,5,6,9,10,12 and 13 were obtained from the Sophora genus for the first time.Compound 1 possessed moderate cytotoxic activity against A549 human tumor cell [IC₅₀（23.05 ± 0.46）μmol•L⁻¹].