A new norclerodan diterpene from twigs and leaves of Croton euryphyllus / 中草药

To study the diterpenoids from the twigs and leaves of Croton euryphyllus. Methods Compounds were isolated and purified by column chromatography on silica gel, MCI, and semi-preparative HPLC, and their structures were elucidated by spectroscopic analysis and comparisons with published literature values. Results Four compounds were obtained from the petroleum ether fraction of 95% alcoholic extract of the twigs and leaves of C. euryphyllus, and structures were identified as crotoeurin D (1), mallotucin C (2), mallotucin D (3), and plaunotol (4), respectively. Conclusion Compound 1 is a new norclerodan diterpene. Compounds 2-4 are isolated from this plant for the first time.

Studies on chemical constituents of Zhuang medicine Excoecaria venenata and their cytotoxic activity / 中国中药杂志

Fourteen compounds were isolated from 95% ethanol extract by silica gel, MCI, and ODS column chromatography. These compounds were respectively identified as quercetin (1), kaempferol (2), (+)-catechin (3), fraxin (4), protocatechuic acid (5), gallic acid (6), methyl gallate (7), ethyl gallate (8), apocynol A (9), baccatin (10), cerevisterol (11), ellagic acid (12), 3, 3',4'-tri-0-methylellagic acid(13) and N-benzoyl-L-phenylalaninyl-N-benzoyl-L-phenylalaninate(14) by analyzing their spectral data and comparing with the previously reported literatures. Except for gallic acid (6), all other compounds were isolated from this plant for the first time. Compounds 1, 2 and 6 showed moderate anti-proliferation activities on tumor cells.

Chemical constituents from EtOAc fraction of Sophora dunnii / 中国中药杂志

Sixteen compounds have been isolated from the EtOAc fraction of 95% ethanolic extract of Sophora dunnii through silica gel, Sephadex LH-20 and semi-prerarative HPLC column chromatographies. Their structures were identified on the basis of NMR and MS spectra data as phaseollidin (1), L-maackiain (2), 2-(2',4'-dihidroxyphenyl)-5,6-methylenedioxy benzofuran (3), 8-demethyl-farrerol (4), liquiritigenin (5), genistein (6), 6-methylgenistein (7), 5-O-methyl genistein (8), 7,2',4'-trihydroxys-5-methoxy-isoflavanone (9), 7, 3', 4'-trihydroxy-isoflavanone (10), erythribyssin D (11), calycosin (12), trans-resveratrol (13), cis-resveratrol (14), stigmasterol (15), β-sitosterol (16). Among these, compounds 1-14 and 16 were isolated from this plant for the first time.