Study on the chemical composition of Caesalpinia sinensis.

Five compounds were isolated from the methanolic extract of Caesalpinia sinensis stems and leaves including a new cassane-type butenolide norditerpenoid compound (1) and a new type of biphenyl compound (2); the compounds were identified as Norcaesalpin-one (1), 4'-hexyl 3-methyl 6-methoxy-[1,1'-biphenyl]-3,4'-dicarboxylate (2), rhapontigenin (3), 3-deoxysappanchalcone (4), isoliquiritigenin (5). Compounds 1-5 were first isolated from C. sinensis. Their structures were elucidaded on the basis of MS, IR, NMR spectroscopic, X-ray diffraction data analyses. The NGF-induced PC12 differentiation assay was performed on compound 1, and the results showed that compound 1 had a promotive effect on PC12 cell differentiation, with a differentiation rate of 12.32%. In addition, compounds 1-5 were evaluated for their cytotoxic activities against four human cancer cell lines (including A-549, BGC-823, MDA-MB-231, HepG2), and the results showed that compounds 3-5 showed inhibitory activity against these cancer cell lines with IC50 values ranging from 22.96 to 74.92 µmol/L, compound 4 showing the best activity against human malignant melanoma cells A375 with an IC50 value of 22.96 µmol/L.

[A new lupane-type triterpenoid from Dichroa hirsuta].

The chemical constituents from methanol extract of Dichroa hirsuta were separated by silica gel and Sephadex LH-20 column chromatography,high pressure preparative liquid chromatography( HPLC) and recrystallization. Their structures were elucidated by NMR and MS. Nine compounds were obtained and their structures were identified as 3ß,21α-O-diacetyl-lup-9( 11)-en-7ß-ol( 1),( Z)-methyl p-hydroxycinnamate( 2),cis-p-coumaric acid ethyl ester( 3),( E)-methyl p-hydroxycinnamate( 4),trans-p-coumaric acid ethyl ester( 5),4( 3 H)-quinazolinone( 6),7-hydroxycoumarin( 7),hydrangenol( 8) and thunberginol C( 9). Compound 1 is a new lupane-type triterpenoid,and compounds 1-5,8-9 were firstly isolated from this plant. Dual reporter assay results showed that compounds 2-5 could activate the Nrf2-ARE signaling pathway.