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Tian-Shung Wu

Publications and source records attributed to Tian-Shung Wu.

13 recordsLinked to original sources
PubMed2003

Cancer chemopreventive activity of acridone alkaloids on Epstein-Barr virus activation and two-stage mouse skin carcinogenesis.

Seventeen acridone alkaloids isolated from the Rutaceous plants were tested for their inhibitory activities against Epstein-Barr virus early antigen activation induced by 12-O-tetradecanoylphorbol-13-acetate in Raji cells. Some prenylated acridones were found to have remarkably potent activities. 1,3-Dihydroxy-10-methyl-2,4-diprenylacridone (18) as synthesized according to these results in vitro, exhibited a marked inhibitory effect on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test. The result of the present investigation indicated that some of these acridone alkaloids may be potentially valuable cancer chemopreventive agents.

Acridines↗
PubMed2003

A novel NO-production-inhibiting triterpene and cytotoxicity of known alkaloids from Euonymus laxiflorus.

A new triterpene, laxifolone A (1), four known sesquiterpene alkaloids, ebenifoline E-II (2), carigorinine E (3), euojaponine C (4), and emarginatine E (5), and six triterpenoids, 3-hydroxyolean-12-en-22,29-gamma-lactone, 3,11-dioxo-beta-amyrene, 3beta,22alpha-dihydroxyolean-12-en-29-oic acid, 28,29-dihydroxyfriedelan-3-one, 29-hydroxy-3-oxo-D:A-friedooleanan-28-oic acid, and putranjivadione, were isolated from the stems and leaves of Euonymus laxiflorus. Structural elucidations of these compounds were established by spectral analysis. Compound 1 displayed significant nitric oxide (NO) inhibitory effect.

Alkaloids↗
PubMed2003

Acetophenone derivatives from Acronychia pedunculata.

Chemical investigation on the stem and root bark of Acronychia pedunculata has resulted in the isolation of five new acetophenones, namely, acronyculatins A (1), B (2), C (3), D (4), and E (5). The structures of these metabolites were established on the basis of their 1D and 2D NMR spectroscopic and mass spectrometric data and by CD spectroscopy. The antioxidant and antityrosinase activities of these five metabolites and acrovestone (6) were evaluated. Among these compounds, 6 showed marginal antioxidant and antityrosinase activities.

Acetophenones↗
PubMed2003

Constituents from the stems of Aristolochia manshuriensis.

In a continuing search for bioactive compounds from Aristolochia species, 28 compounds, including three new constituents, demethylaristofolin E (1), aristomanoside (2), and dehydrooxoperezinone (3), were isolated from an extract of the stems of Aristolochia manshuriensis. The structures of these compounds were established by extensive 1D and 2D NMR spectral studies. Among these compounds, dehydrooxoperezinone (3) was found to inhibit the replication of HIV, with an EC(50) value of 17.5 microg/mL and a therapeutic index of 1.43.

Anti-HIV Agents↗
PubMed2003

Cytotoxic anthraquinones from the stems of Rubia wallichiana Decne.

From the stems of Rubia wallichiana DECNE, thirty-four structurally related compounds were isolated and identified. Three of them, namely rubiawallin-A (1), -B (2), and -C (3), constitute the first report of their occurrence from the natural source. Their structures were determined by comprehensive analyses of their 1D and 2D NMR, and electron impact (EI) mass spectral data. Furthermore, an in vitro screening of cytotoxicity of the isolated compounds was also evaluated. Among the testing compounds, 1-hydroxy-2-hydroxymethyl-3-methoxyanthraquinone (4) demonstrated most effective cytotoxicity towards Hepa-3B and Colo-205 cells.

Anthraquinones↗
PubMed2002

Acute administration of Ginkgo biloba extract (EGb 761) affords neuroprotection against permanent and transient focal cerebral ischemia in Sprague-Dawley rats.

We examined the neuroprotective action of a standardized extract of Ginkgo biloba leaves (EGb 761) in permanent and transient middle cerebral artery (MCA) occlusion models in Sprague-Dawley rats. Forty-four animals were given either EGb 761 (50-200 mg/kg) or vehicle intraperitoneally, 1 hr before permanent MCA occlusion, to evaluate the dose-response effects. An additional 58 animals received EGb 761 (200 mg/kg) or vehicle, 0.5- 4 hr after permanent MCA occlusion, for establishing the therapeutic window. Delayed treatment was also employed in 110 animals treated with either EGb 761 (100-200 mg/kg) or vehicle at 2-3 hr following transient focal cerebral ischemia induced by MCA occlusion for 2 hr. Neurobehavioral scores were determined 22-24 hr after permanent MCA occlusion and either 3 or 7 days after transient MCA occlusion, and brain infarction volumes were measured upon sacrifice. Local cortical blood flow (LCBF) was serially measured in a subset of animals receiving EGb 761 (100-200 mg/kg) or vehicle, 0.5 hr and 2 hr after permanent and transient MCA occlusion, respectively. Relative to vehicle-treated controls, rats pretreated with EGb761 (100 and 200 mg/kg) had significantly reduced infarct volumes, by 36% and 49%, respectively, and improved sensory behavior (P < 0.05). Delayed treatment with EGb 761 also significantly reduced brain infarction, by 20-29% and 31%, when given up to 2 and 3 hr following transient and permanent MCA occlusion, respectively, whereas improved neurobehavioral scores were noted up to 2 hr after the onset of MCA occlusion (P < 0.05). LCBF was significantly improved in the ipsilateral cortex following the EGb 761 treatment, whereas a higher dose showed a more sustained effect. In conclusion, EGb 761 protected against transient and permanent focal cerebral ischemia and was effective after a prolonged reperfusion period even when therapy is delayed up to 2 hr. This neuroprotection may be at least partially attributed to the beneficial effects of selectively improved LCBF in the area at risk of infarction.

Animals↗
PubMed2002

Triterpenoids from Rubia yunnanensis.

Five new triterpenoids, rubiarbonones D (1), E (5), and F (2), and rubiarbosides F (3) and G (4), together with nine known compounds, were isolated from the roots of Rubia yunnanensis. The structures of 1-12 were elucidated by spectroscopic methods. The antiplatelet aggregation activities of rubiarbonone A (6) and rubiarbonol A (8) and B (9) were investigated with a standard protocol.

Drugs, Chinese Herbal↗
PubMed2002

Constituents of the stigmas of Crocus sativus and their tyrosinase inhibitory activity.

Four new compounds, crocusatins F (1), G (2), H (3), and I (4a), together with 21 known compounds, were isolated from an aqueous extract of the stigmas of Crocus sativus (saffron). The structures of 1-4 were established by spectral methods. The tyrosinase inhibitory activities of all 25 compounds isolated were evaluated in vitro using mushroom tyrosinase. Among them, crocusatin H (3), crocin-1 (5), and crocin-3 (6) showed significant tyrosinase inhibitory activity.

Crocus↗
PubMed2002

Constituents from the root and stem of Aristolochia elegans.

Four new tetralones, aristelegone-A (1), aristelegone-B (2), aristelegone-C (3), and aristelegone-D (4); one new isoquinoline, pericampylinone-A (5); four new biphenyl ethers, aristogin-A (6), aristogin-B (7), aristogin-D (8), and aristogin-E (9); three new lignans, aristelegin-A (10), aristelegin-B (11), and aristelegin-C (12); and a new dimer, aristolin (13), have been isolated from the root and stem of Aristolochia elegans. The structures were established on the basis of 1D and 2D NMR and mass spectral data. This is the first report of isoquinolones and biphenyl ethers from this plant which may be representative units for the formation of bisbenzylisoquinoline alkaloids that are common metabolites of Aristolochia species. Aristolin (13) is also the first report of a diterpene linked with an aristolochic acid.

Alkaloids↗
PubMed2002

Marked decrease of cyclosporin absorption caused by phellamurin in rats.

Phellamurin is a flavonoid glycoside that is abundant in the leaves of Phellodendron wilsonii Hayata et Kanehira (Rutaceae). In vitro everted rat intestine study indicated that phellamurin inhibited intestinal P-glycoprotein in a dose-dependent manner. In order to investigate the effect of phellamurin on cyclosporin absorption and disposition, rats were given cyclosporin (5 mg/kg) with or without phellamurin in a parallel design. Fluorescence polarization immunoassay was used to determine the blood concentration of cyclosporin. Unanticipatedly, our results indicated that the coadministration of phellamurin significantly decreased the Cmax of cyclosporin by 77 % and reduced the AUC(0-infinity) of cyclosporin by 56 %. This indicated that a serious interaction occurred between phellamurin with cyclosporin. To ensure the efficacy of cyclosporin, we suggest that the coadministration of phellamurin or Phellodendron wilsonii with cyclosporin should be avoided.

Animals↗
PubMed2002

New pavine N-oxide alkaloids from the stem bark of Cryptocarya chinensis Hemsl.

Three new pavine N-oxide alkaloids, (-)-isocaryachine-N-oxide B, (+)-caryachine-N-oxide, (-)-caryachine-N-oxide, and a new isoquinoline alkaloid, 6,7-methylenedioxy-N-methylisoquinoline together with 11 known alkaloids were isolated and characterized from the stem bark of Cryptocarya chinensis. The structures of the isolated compounds were determined by spectral methods. The stereochemistry of pavine-N-oxide alkaloids is also discussed.

Alkaloids↗
PubMed2002

Constituents of the roots of Rubia yunnanensis.

Four new naphthohydroquinones, rubinaphthins A (1), B (2), C (3), and D (4), together with 11 known compounds were isolated and characterized from the roots of Rubia yunnanensis. The structures of 1-4 were elucidated by spectral analysis and chemical transformation.

Hydroquinones↗