Characterization And Bioactivity Of Natural Products From Euphorbia Hirta

The chemical constituents of Euphorbia hirta were studied systematically.Some of the compounds obtained were tested for the in vitro anti-proliferative activity against several strains of cancer cell lines and some compounds exhibited moderate inhibitory activity.The chemical constituents of 95%ethanol extract of the aerial part of Euphorbia hirta were studied systematically.A total of 51 secondary metabolites including 8 new ones were obtained after separation by column chromatography on silica gel,C18 reverse-phased silica gel,and Sephadex LH-20 as well as semi-preparative HPLC.The structures of the compounds were determined on the basis of various spectroscopic analyses,including 1D and 2D NMR and HRESIMS.The absolute configurations of the new compounds were determined by chemical method in combination with comparison of the CD spectra.The 8 new compounds obtained were identified as lignans:euphorhirtins A-D(1-4),5-methoxyvirgatusin(6),7S-ethoxyisolintetralin(7),7R-ethoxyisolintetralin(8),and 7R-ethoxy-3-methoxy-isolintetralin(9).The 43 known compounds were characterized as 14 lignans,7-oxocubebin dimethylether(5),virgatusin(10),virgatusin 16(11),urinaligran(12),phyllanthin(13),niranthin(14),5-demethoxyniranthin(15),lintetralin(16),phyltetralin(17),isolintetralin(18),5-methoxyursehemin(19),7-hydroxyhinokinin(20),hypophyllanthin(21),and neonirtetralin(22);12 triterpenoids,cycloart-22-ene-3,25-diol(23),25-hydroperoxycycloart-23-en-3-ol(24),(24R)-cycloartane-3,24,25-triol(25),(24S)-9,19-cycloart-25-ene-3β1,24-diol(26),(23R)-3β-cycloart-25-diene-ol(27),24(E)-3-hydroxycycloart-24-en-26-al(28),3β-hydroxy-9,19-cycloart-24-oic acid(29),taraxerol(30),taraxerone(31),3,3-hydroxyolean-12-ene-ll-one(32),3,3-hydroxyursan-12-ene-ll-one(33),and glochidiol(34);four diterpenoids,cassipourol(35),callyspinol(36),phytol(37),and spruceanol(38);one monoterpene,(E)-linalool-l-oic acid(39);seven aromatic compounds,ferulic acid(40),3-methoxy-4-hydroxybenzaldehyde(41),coniferaldehyde(42),4-hydroxybenzalde-hyde(43),2,4-dihydroxybenzoic acid(44),2-hydroxyphenylacetic acid(45),and protocatechuic acid(46);two steroids,β-sitosterol(47)and stigmasterol(48);three miscellaneous types of compounds,dehydrololiolide(49),ethyl 3-(4-methyl-2,5-dioxo-2,5-dihydro-1H-pyrrol-3-yl)propanoate(50),and docosanoic acid oxiranyl-methylester(51);Compounds 1-22 were evaluated for their anti-proliferative activity against the cancer cell lines Hep G2,A549,and DU145 and compounds 15 and 19 showed moderate inhibitory activity against the Hep G2 cells with IC50 values 7.2 and 8.5 μM.