Ming-An Ouyang

Bioactive metabolites from a marine-derived strain of the fungus Neosartorya fischeri

Two new compounds named fischeacid (1) and fischexanthone (2), together with eight known compounds, were obtained from the culture of a marine-derived fungus Neosartorya fischeri strain 1008F1. The structures of the new compounds were elucidated based on the spectroscopic data. Bioassays indicated that AGI-B4 (5) and 3,4-dihydroxybenzoic acid (10) showed potent inhibitory effect on the replication of tobacco mosaic virus, and AGI-B4 also possessed an inhibition of the cell proliferation of human gastric cancer cell line SGC-7901 and hepatic cancer cells BEL-7404.

Two new phenolic water-soluble constituents from branch bark of Davidia involucrata

Two new phenolic water-soluble constituents, involcranoside A (1) and involcranoside B (2) have been isolated along with five known phenolic compounds: 3,4-dimethoxyphenyl-O-β-D-gluco-pyranoside (3), picein (4), and 1,4-dihydroxy-3-methoxy-phenyl-4-O-β-D-glucopyranoside (5), leonuriside A (6) and 4-hydroxy-3-methoxybenzoic acid (7) from the branch bark of Davidia involucrata. Identification of their structures was achieved by 1D and 2D NMR experiments, including 1H-1H COSY, NOESY, HMQC and HMBC methods and FAB mass spectral data.

Water-soluble phenylpropanoid constituents from aerial roots of Ficus microcarpa.

New water-soluble phenylpropanoid constituents, ficuscarpanoside A, guaiacylglycerol 9-O-β-D-glucopyranoside, and erythro-guaiacylglycerol 9-O-β-D-glucopyranoside, along with known guaiacylglycerol, erythro-guaiacylglycerol, 4-methoxy guaiacylglycerol 7-O-β-D-glucopyranoside, and 3-(4-hydroxy-3-methoxy phenyl) propan-1,2-diol, have been isolated from the aerial roots of Ficus microcarpa. Their structures were elucidated on the basis of 1D and 2D NMR experiments.

A new seco-neolignan glycoside from the root bark of Ailanthus altissima

A new seco-neolignan glycoside, seco-dehydrodiconiferyl alcohol-4-O-β-D-glucopyranoside (1), together with eight known compounds, were obtained from the EtOH extract of the root bark of Ailanthus altissima. Their structures were elucidated based on the spectroscopic data. Three neolignan glycosides including 7,9,9′-trihydroxy-3,3′,5′-trimethoxy-8-O-4′-neolignan-4-O-β-D-glucopyranoside (5), sonchifolignan B (6) and citrusin B (7) exhibited moderate in vitro inhibitory effect on tobacco mosaic virus replication with IC50 values 0.30, 0.35 and 0.26 mmol L−1, respectively.

New caffeoyl derivatives from the leaves of Davidia involucrata

Three new caffeoyl galactoic acid derivatives, davidiosides A–C (1–3) together with four known caffeoyl derivatives such as: caffeic acid (4), methyl caffeate (5), chlorogenic acid (6), and methyl chlorogenate (7) were isolated from the leaves of Davidia involucrate. The new structures were determined by spectroscopic data and chemical evidence.

Structure-activity relationship of Triterpenes and derived Glycosides against cancer cells and mechanism of apoptosis induction

Abstract Triterpenoids possess a wide range of biological effects. Here, the cytotoxic activities of 55 triterpenes and derived glycosides against BEL-7404 and SGC-7901 cells were assessed, and structure-activity relationships were analysed accordingly. Nine of them effectively inhibited the two cell lines. In particular, compounds 49 and 52 inhibited BEL-7404 cells as efficiently as 5’-fluorouracil (IC50 values 0.46 and 1.48, respectively). Moreover, we found that compounds 49 and 52 induced apoptosis in BEL-7404 cells. Indeed, DNA fragmentation assay showed a time-dependent degradation of DNA after treatment of cells with compounds 49 and 52. In addition, Bax gene expression levels were increased after treatment with these compounds, in a concentration-dependent manner. Taken together, our findings suggested that compounds 49 and 52 induce apoptosis in BEL-7404 cells by upregulating the Bax gene without affecting Bcl-2 gene expression.

Novel 4-(2-methylphenyl)-flavan, rhusjavanins A and B, from the roots of Rhus semialata

In this study, two novel flavan derivatives, namely, rhusjavanins A and B, along with two known flavans 2,3-trans-3,4-trans-3,4,7,4′-tetrahydroxyflavan and 2,3-trans-3,4-cis-3,4,7,4′-tetrahydroxyflavan, have been isolated from the roots of Rhus javanica. The structures were elucidated on the basis of spectroscopic data.