The present study investigated the chemical constituents of Scrophulariae Radix and their antitumor activities in vitro. The compounds in the ethyl acetate extract were separated and purified by conventional column chromatographies(such as silica gel, Sephadex LH-20, and ODS column) and semi-preparative high-performance liquid chromatography(HPLC), and their structures were identified by various spectral techniques such as nuclear magnetic resonance(NMR) and mass spectrometry(MS). Twenty-three compounds were isolated and identified as benzyl-β-D-(3',6'-di-O-acetyl) glucoside(1), 5-O-p-methoxybenzoyl kojic acid(2), 5-O-methoxybenzoyl kojic acid(3), 7-O-methylbenzoyl kojic acid(4), 5-O-benzoyl kojic acid(5), methyl ferulate ethyl ether(6), trans-ferulic acid(7), trans-isoferulic acid(8), trans-caffeic acid(9), trans-caffeic acid methyl ester(10), caffeic acid ethyl ester(11), trans-cinnamic acid(12), trans-p-methoxycinnamic acid(13), trans-p-hydroxycinnamic acid(14), trans-p-hydroxycinnamic acid methyl ester(15), 2-(3,4-dihydroxyphenethyl) alcohol(16),(p-hydroxyphenyl) propanoic acid(17), coniferaldehyde(18), sinapaldehyde(19), benzyl β-primeveroside(20), 5-(hydroxymethyl) furfural(21), furan-2-carboxylic acid(22), and decanedioic acid(23). Among them, compound 1 is a new benzyl glucoside, compounds 2-4 are new pyranone compounds, compound 5 is a new natural product of pyranone. The NMR data of compounds 5 and 6 are reported for the first time. Compounds 6 and 20 were isolated from the Scrophularia plant for the first time. Compounds 8, 11, 14, 16, 18, 19, 22, and 23 were isolated from this plant for the first time. The in vitro cytotoxic activities of these compounds against three tumor cell lines(HepG2, A549, and 4 T1) were evaluated. The results showed that compounds 10 and 15 showed cytotoxic activities against HepG2 cells with IC_(50) values of(19.46±0.48) μmol·L~(-1) and(46.10±1.21) μmol·L~(-1).
Keywords: Scrophulariae Radix; antitumor activity; chemical constituent; structural identification.