5,3',4'-triacetoxy-3,6,7-trimethoxy flavone

Background: The seeds of Zizyphus jujuba Mill. (Rhamnaceae) are astringent, aphrodisiac, tonic; used to cure cough, asthma, vomiting, burning sensation, biliousness, leucorrhoea, and eye infections in traditional systems of medicine. Materials and methods: The methanol extract of seeds of Z. jujuba was partitioned into petroleum ether and water soluble fractions. Isolation of compounds was performed by silica gel column chromatography. The structures of isolated compounds were established on the basis of spectral studies and chemical reactions. Results: Chromatographic separation of methanolic extract of seeds yielded three new phyto-constituents characterized as 3, 5, 7-trimethoxy-8, 3', 4', 5'-tetrahydroxy flavone-6-oxy hexahydrobisabolene ether (4), 1, 9-dihydroxy tetrahydrogeranyl-8-oxy-O-β-D-glucuronopyranoside (5) and terahydrogeranyl-8-oxy-O-β-D-glucuronopyranosyl (2a→1b)-O-β-D-glucofuranosyl (2b→1c)-O-β-D-glucofuranosyl (2c→1d)-O-β-D-glucopyranosyl (2d→1e)-O-β-D-glucopyranosyl (2c→f)-O-β-D-glucopyranosyl-2f-benzoate (6) along with five known compounds, palmitoyl palmitoleoyl arachidoyl glyceride (1), tetratriacontenoic acid (2), palmitoyl oleoyl linolenoyl glyceride (3), hexanyl tetraglucoside (7) and pentasaccharide (8). Conclusion: This is the first report of saturated monoterpene and sesquiterpene derivatives from jujuba seeds.

A series of 5,6,7-trimethoxyflavones 1a-1g and their derivatives 2a-2g, 3a-3d, 4 and 5, including the natural products 5,6,7-trimethoxy-4'-hydroxyflavone (1a), 5,6,7,3',4' -pentamethoxyflavone (sinensetin, 1 b), 5,6,7-trimethoxy-3',4'-methyl enedioxy flavone (1c), 5,6,7,3'-tetramethoxy-4,5'-methylenedioxyflavone (1e), 5,6,7, 3',4',5'-hextamethoxyflavone (1 g), 5-hydroxy-3,4,2',3',4'-pentamethoxy chal-cone (2 b), 5,4'-dihydroxy-6,7-dimethoxy flavone (cirsimaritin, 3a) and 5-hydroxy-6,7,3', 4'-tetramethoxyflavone (5-demethylsinensetin, 3 b), 3,5,6,7,3',4'-hexamethoxyflavone (3-methoxysinensetin, 4) and 5'-hydroxy-3,6,7,3',4'-pentamethoxyflavone (5) were synthesized. Their anti-proliferative activity in vitro was evaluated against a panel of four human cancer cell lines (Aspc-1, HCT-116, HepG-2 and SUN-5) by the CTG assay. The results showed that most of the synthetic compounds exhibited moderate to high anti-proliferative activities. In particular, compound 3c possess IC50 (5.30 μM) values below 10 μM against Aspc-1 cells and are worthy of further investigation.

The ethanolic extract from leaves of Rauia resinosa, Rutaceae, provided a new flavone, 5-hydroxy-5',6,7-trimethoxy-3',4'-methylenedioxyflavone (1), in addition to four known compounds: 3',4',5,5',7-pentamethoxyflavone (2), 5,7,8-trimethoxy-3'4'-methylenedioxyflavone (3), 3',4',5,7,8-pentamethoxyflavone (4) and β-sitosterol (5). The structures of all compounds were established on the basis of spectroscopic methods, mainly 1D and 2D NMR, UPLC-DAD-MS and UPLC-ESI-MS/MS, involving comparison with literature data. Cytotoxicity of leaves and stems extracts, their fractions and compounds (2), (3), (4) and (5) were evaluated against T24 (bladder carcinoma), TOV-21-G (ovarian adenocarcinoma) and HepG2 (liver carcinoma) cell lines.