Seven stilbenes and one catechin were bioactivity-guidedly isolated from the rhizomes of Rheum palmatem. Their structures were identified as piceatannol(1), resveratrol(2), piceid(3), rhapontigenin(4), piceatannol-3'-O-β-D-glucopyranoside(5), rhaponticin(6), catechin(7) and desoxyrhapontigenin(8). Anti-monoamine oxidase (MAO) activities of compounds 1–8 were tested. Compounds 1 and 8 showed sig...

Seven stilbenes and one catechin were bioactivity-guidedly isolated from the rhizomes of Rheum palmatem. Their structures were identified as piceatannol(1), resveratrol(2), piceid(3), rhapontigenin(4), piceatannol-3'-O-β-D-glucopyranoside(5), rhaponticin(6), catechin(7) and desoxyrhapontigenin(8). Anti-monoamine oxidase (MAO) activities of compounds 1–8 were tested. Compounds 1 and 8 showed sig...

The effects of ethanol extracts of three Chinese medicinal plants Dahuang (Rheum palmatum L.), Badou (Croton tiglium L.), and Huomaren (Cannabis sativa L.), on ion transport of the rat intestinal epithelia were studied. Rat intestinal epithelia mounted in an Ussing chamber attached with voltage/current clamp were used for measuring changes of the short-circuit current across the epithelia. The ...

Hepatitis B induced by hepatitis B virus (HBV) remains a major public health problem worldwide. Although several antiviral drugs have been approved for hepatitis B, they cause significant dose-dependent side-effects (interferon-alpha) and drug resistance (lamivudine, etc.). Safe and potent new anti-HBV drugs are urgently needed. Traditional Chinese medicine (TCM) is an established segment of th...

Historically, Chinese herbal medicines have been widely used in the treatment of hyperglycemia, but the mechanisms underlying their effectiveness remain largely unknown. Here, we screened a compound library primarily comprised of natural compounds extracted from herbs and marine organisms. The results showed that emodin, a natural compound from Rheum palmatum Linn, inhibited DPP4 activity with ...

Background and objectives: Skin hyperpigmentation usually indicates an increase in production and accumulation of melanin. Hyperpigmentary disorders are characterized by the appearance of melasma, freckles and lentigo on the skin surface which can cause psychological disturbances. Herbal products could be extensively preferable due to their widespread accessibility and the vast...

To provide a basis for controlling the quality of rhubarb under artificial cultivation, the present work was designed to evaluate the contents of 14 active pharmaceutical ingredients (API) of rhubarb in major rhubarb production areas in China and analyze the correlations between the contents of API and such factors as species, geographic distribution and soil. The levels of fourteen API in rhub...

BACKGROUND To find new, crude anti-obesity drugs from natural sources through the inhibition of adsorption of dietary lipids, in vitro porcine pancreatic lipase (PPL; triacylglycerol lipase, EC 3.1.1.3) inhibitory tests were carried out on selected plants with weight-reducing or related potential, used in Chinese traditional medicine. METHODS The methanolic extracts of 37 traditional Chinese ...

Benzalacetone synthase, from the medicinal plant Rheum palmatum (RpBAS), is a plant-specific chalcone synthase (CHS) superfamily of type III polyketide synthase (PKS). RpBAS catalyzes the one-step, decarboxylative condensation of 4-coumaroyl-CoA with malonyl-CoA to produce the C(6)-C(4) benzalacetone scaffold. The X-ray crystal structures of RpBAS confirmed that the diketide-forming activity is...