• Archives of Pharmacal Research
• /
• v.22 no.4
• /
• pp.401-403
• /
• 1999

In continued studies on cultivated Korean rhubarb rhizomes (Rheum undulatum), three known stillbenes (desoxyrhapontigenin, rhapontigenin, piceatannol) have been screened for activity on blood platelet aggregation. Both rhapontigenin and desoxyrhapontigenin exhibited strong inhibition on the aggregation induced by arachidonic acid collagen. However, piceatannol did not show inhibition. These inhibitory effects may partially contribute to anti-blood stagnancy activity of rhubarb.

• Korean Journal of Pharmacognosy
• /
• v.34 no.1 s.132
• /
• pp.25-27
• /
• 2003

In order to clarify the anti-thrombosis activity of rhubarb, we investigated the effect of stilbene derivatives from rhizomes of Rheum undulatun on cyclooxygenase activity. Stilbene derivatives (desoxyrhapontigenin, rhapontigenin, piceatannol) exhibited the inhibitory effects on COX-1, and desoxyrhapontigenin showed inhibitory effect on COX-2. These inhibitory effect may partially contributed to anti-thrombosis activity of rhubarb.

• Korean Journal of Pharmacognosy
• /
• v.31 no.2
• /
• pp.245-248
• /
• 2000

As a series of the studies on cultivated Korean rhubarb rhizomes (Rheum undulatum), five stilbene derivatives were screened for inhibitory activity against $5{\alpha}-reductase$. Of these, desoxyrhapontigenin, rhapontigenin, and piceatannol exhibited inhibition, whereas, two other stilbene glycosides, rhaponticin and $piceatannol-3'-O-{\beta}-D-glucopyranoside$ did not show the inhibition.

• YAKHAK HOEJI
• /
• v.42 no.1
• /
• pp.1-4
• /
• 1998

In continued studies on cultivated Korean rhubarb rhizomes, three additional stilbene compounds were isolated from water extract by column chromatographic separation using Sepha dex LH-20, ODS-gel. Compound I, desoxyrhapontigenin(3,5-dihydroxy-4`-methoxystilbene), Compound II, rhapontigenin(3,3`,5-trihydroxy-4`-methoxystilbene), and compound III, piceatannol(3,3`,4`,5-tetrahydroxystilbene) were elucidated based on physico-chemical and spectroscopic evidences(UV, IR, $^1H$-NMR, $^13C$-NMR and Mass).

• Bulletin of the Korean Chemical Society
• /
• v.31 no.4
• /
• pp.971-975
• /
• 2010

Eight hydroxylated stilbene derivatives including resveratrol, desoxyrhapontigenin and piceatannol as potential radical scavenger and tyrosinase inhibitor are synthesized using optimized Wittig-Horner reaction for excellent trans-selectivity in good yields. Antioxidant activity was tested against ABTS radical and tyrosinase inhibitory activity was performed with L-tyrosine as the substrate based on previous procedure with some modification. In general, catecholic stilbenes showed stronger activity against ABTS radical and resorcinolic moiety showed stronger tyrosinase inhibitory activity. Synthetic piceatannol which containing both catecholic and resorcinolic moieties showed the strongest activity in both as ABTS radical scavenger and tyrosinase inhibitor with $IC_{50}$ values of 4.1 and $8.6\;{\mu}M$, respectively.

• Archives of Pharmacal Research
• /
• v.28 no.9
• /
• pp.1027-1030
• /
• 2005

The antidiabetic-activity-guided fractionation and isolation of the $80\%$ EtOH extracts obtained from cultivated Korean Rhubarb rhizomes (Rheum undulatum, Polygonaceae) led to the isolation and characterization of one stilbene, desoxyrhapontigenin(1) and two anthraquinones, emodin (2) and chrysophanol (3). Their structures were established by chemical and spectroscopic methods. Compounds 1, 2, and 3 inhibited postprandial hyperglycemia by 35.8, 29.5, $42.3\%$, respectively.

• Journal of Food Hygiene and Safety
• /
• v.28 no.4
• /
• pp.330-336
• /
• 2013

Rheum tanguticum has long been used in oriental medicine as antipyretics, analgesics, anti-inflammation, aperient, hypertension medicine and medicine for skin disease. This study has investigated the effectiveness of defense for gastritis making use of Rheum tanguticum and its similar plants, Rumex cripus, Rheum officinale, Rhem palmatum and Rheum undulatum. Chysophanol, chrysophanol-8-O-glc, Desoxyrhaponticin desoxyrhaponti-genin, emodin, isorhaponticin, 2-methoxy-4-hydroxyanthraquinone-5-O-glc, physcion, pirace-tannol-3'-O-glc, resveratrol, rhaponticin and rhapontigenin are used as the components of Rheum tanguticum. In HCl ethanol-induced gastritis in rat, the most effective extract was 70 percent ethanol which is of Rheum tanguticum, showing the inhibition of 91.8 percent to the gastric lesions. 70% ethanol extract of Rhem palmatum and Rumex cripus shown inhibition of 75.6 percent and 73.2 percent, respectively. This effectiveness is considered as acid-neutralizing capacity, anti-H.pylori and anti-oxidant activity. 70% ethanol extract of Rheum tanguticum and its component, piracetannol-3'-O-glc exhibited higher free radical scavenging activity than others. These results suggest that Rheum species extracts and their active components could be utilized for the treatment of gastritis. Furthermore, these results are expected to contribute the standardization with objectivity and reliability for Rheum species, medicinal herbs. In addition, it can contribute to the prevention of indiscriminate distribution of imitation, and the rising rate of dependence on imports of medicinal herbs, and mixing prevention of low-quality goods.