Ling Dong Kong

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Three protoberberine alkaloids jatrorrhizine, berberine and palmatine were isolated from the monoamine oxidase (MAO) inhibitory fraction of the methanol extract of Coptis chinensis rhizoma. Jatrorrhizine was shown to inhibit non-competitively both MAO-A and -B from rat brain mitochondria with the IC50 values of 4 and 62 microM, respectively. Berberine only(More)
A total of seventeen phytochemicals including seven alkaloids (piperine, strychnine, brucine, stachydrine, tetrandrine, frangchinoline and sinomenine), four phenols (paeonol, honokiol, magnolol and eugenol) and six anthraquinones (emodin, rhein, chrysorphanol, aloe-emodin, physcion and 1,8-dihydroxyanthraquinone) was examined for inhibitory activity of(More)
In this study we have investigated the effects of administration of procyanidins from grape seeds on serum uric acid levels in a model of hyperuricaemia in mice pretreated with oxonate, as well as the xanthine dehydrogenase and xanthine oxidase activities in mouse liver in vivo. The procyanidins, when orally administered to the oxonate-pretreated(More)
The methanol extract of the stem of Sinofranchetia chinensis inhibited the activity of xanthine oxidase in vitro. Bioassay-guided purification led to the isolation of liquiritigenin and isoliquiritigenin as the main xanthine oxidase inhibitors. This inhibition of enzyme activity was found to be dose dependent, with an IC50 value of approximately 49.3 μM for(More)
The enzyme xanthine oxidase catalyses the oxidation of hypoxanthine to xanthine and then to uric acid, which plays a crucial role in gout. A total of 122 traditional Chinese medicinal plants, selected according to the clinical efficacy and prescription frequency for the treatment of gout and other hyperuricemia-related disorders, have been evaluated for the(More)
Psoralen and isopsoralen, furocoumarins isolated from the plant Psoralea corylifolia L., were demonstrated to exhibit in vitro inhibitory actions on monoamine oxidase (MAO) activities in rat brain mitochondria, preferentially inhibiting MAO-A activity over MAO-B activity. This inhibition of enzyme activities was found to be dose-dependent and reversible.(More)
Cancer remains one of the leading causes of death throughout the world. One of the important reasons why conventional treatments fail is the development of resistance to therapeutics. The dual effect concept and self-defense mechanism plus the threshold theory might in part explain the development of resistance, however, the primary cause is unclear. A(More)
The bioassay guided refractionation of the methanol extract of roots and rhizomes of Veratrum taliense (Liliaceae) yielded five stilbenoids: veraphenol, resveratrol, piceid, isorhapontin, and mulberroside E, all inhibiting xanthine oxidase (XO, EC 1.2.3.2.) in vitro in a dose-dependent manner with IC50 values of 11.0, 96.7, 66.1, 70.0, and 78.4 microM,(More)
Fractionation of the xanthine oxidase inhibitory methanol extract of Conyza bonariensis afforded three glycosides, in addition to nine known compounds including amyrin, beta-sitostero1 daucosterol, syringic acid 3-hydroxy-5-methoxybenzoic acid, eugenol 4-O-glucopyranoside, and luteolin, apigenin and takakin 8-O-glucuronide. The structures of the glycosides(More)
Repeated fractionations of the methanol extract of the subterranean parts (rhizomes and roots) of Gentiana siphonantha afforded two new and five known secoiridoids, in addition to the widespread plant constituents beta-sitiosterol, daucosterol and oleanolic acid. The structures of the new acyl secoiridoid glycosides were elucidated as 6'-gentisoyl(More)