• Korean Journal of Pharmacognosy
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• v.27 no.4
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• pp.366-370
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• 1996

Fruits of Rubus coreanum (Korean name: Bog-bun-ja) have been used in oriental traditional medicine as the remedies for impotence, pollution, premature ejaculation and frequency of urination etc. It is known to have phenolic compounds as an astringent. By means of chromatographic methods, four hydrolyzable tannins were isolated from the fruits of R. coreanum. The structures of these compounds were established as gallic acid, 2,3(S)-HHDP-D-glucopyranose, sanguiin H-4 and sanguiin H-6 on the basis of physicochemical and spectroscopic evidences.

• YAKHAK HOEJI
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• v.40 no.6
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• pp.666-669
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• 1996

Four hydrolyzable tannins were isolated from the leaves of Rubus coreanum. The structures of these compounds were elucidated as methyl gallate(1), 1(${\beta}$)-O-galloyl pedun culagin(2), sanguiin H-2(3) and sanguiin H-6(4) on the basis of physicochemical and spectroscopic evidences. These compounds were found from this plant for the first time.

• Archives of Pharmacal Research
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• v.28 no.11
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• pp.1270-1274
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• 2005

The vascular endothelial growth factor (VEGF) plays a key role in angiogenesis, which is a process where new blood vessels develop from the endothelium of a pre-existing vasculature. VEGF exerts its activity by binding to its receptor tyrosine kinase, KDR/Flk-1, which is expressed on the surface of endothelial cells. A methanol extract and organic solvent (n-hexane, ethyl acetate, n-butanol, aqueous) fractions from Rubus coreanus were examined for their inhibitory effects on VEGF binding to the VEGF receptor. The methanol extract from the crude drug were found to significantly inhibit VEGF binding to the VEGF receptor ($IC_{50}$$\thickapprox$27 $\mu$g/mL). Among the fractions examined, the aqueous fraction from the medicinal plant showed potent inhibitory effects against the binding of KDR/Flk-1-Fc to immobilized $VEGF_{165}$ in a dose­dependent manner ($IC_{50}$$\thickapprox$11 $\mu$g/mL). Sanguiin H-6 was isolated as an active principle from the aqueous fraction, and inhibited the binding of KDR/Flk-1-Fc to immobilized $VEGF_{165}$ in a dose­dependent manner ($IC_{50}$$\thickapprox$0.3 $\mu$g/mL). In addition, sanguiin H-6 efficiently blocked the VEGF­induced HUVEC proliferation in a dose-dependent manner ($IC_{50}$$\thickapprox$7.4 $\mu$g/mL) but had no effect on the growth of HT1080 human fibrosarcoma cells. This suggests that sanguiin H-6 might be a potential anti-angiogenic agent.

• Natural Product Sciences
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• v.25 no.1
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• pp.28-33
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• 2019

A popular approach for the study of estrogen receptor ${\alpha}$ inhibition is to investigate the protein-protein interaction between the estrogen receptor (ER) and the coactivator surface. In our study, we investigated phytochemicals from Rubus coreanus that were able to disrupt $ER{\alpha}$ and coactivator interaction with an $ER{\alpha}$ antagonist. The E-screen assay and molecular docking analysis were performed to evaluate the effects of the estrogenic activity of R. coreanus extract and its constituents on the MCF-7 human breast cancer cell line. At $100{\mu}g/mL$, R. coreanus extract significantly stimulated cell proliferation ($574.57{\pm}8.56%$). Sanguiin H6, which was isolated from R. coreanus, demonstrated the strongest affinity for the $ER{\alpha}$ coactivator-binding site in molecular docking analysis, with a binding energy of -250.149. The initial results of the study indicated that sanguiin H6 contributed to the estrogenic activity of R. coreanus through the activation of the $ER{\alpha}$ coactivator-binding site.

• YAKHAK HOEJI
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• v.39 no.2
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• pp.200-204
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• 1995

Chemical examination of the leaves of Rubus coreanum has led to the isolation and characterization of six phenolic compounds. The structures of these compounds were elucidated as kaempferol(l), quercetin(2), sodium salt of quercetin 3-O-$\beta$-D-glucuronide(3), sodium carboxylate of quercetin 3-O-$\beta$-D-glucuronide(4), ellagic acid(5) and sanguiin H-5(6) on the basis of physicochemical and spectroscopic evidences.