• Korean Journal of Pharmacognosy
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• v.43 no.2
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• pp.101-106
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• 2012

The anti-hyperlipidemic effect of Houttuynia cordata was assessed in poloxamer-407 induced hyperlipidemic mice model. The butanol fraction and its isolated compound, quercetin-3-O-rhamnoside, significantly reduced the blood triglyceride and total-cholesterol level and increased the blood HDL-cholesterol level. They also showed the significant reductive effect on the blood AST and ALT level, rising in proportion to the liver damage, in hyperlipidemic mice.

• The Korea Journal of Herbology
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• v.24 no.4
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• pp.137-142
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• 2009

Objectives : This study was performed to investigate the antioxidant activities of isolated compounds from the shoot of Aralia elata. Methods : The methanol extract from the shoot of Aralia elata was fractionated into ethyl acetate, n-BuOH and $H_2O$ layers through solvent fractionation. Repeated silica gel, ODS column chromatography of n-BuOH layer afforded four flavonol glycosides. Their antioxidant activity was determined by measuring free radical scavenging activity by DPPH, ABTS and superoxide dismutase (SOD) like activity assay. Results : They were identified as quercetin 3,7-di-O-$\alpha$-rhamnopyranoside (1), quercetin 3-O-$\beta$-D-galactoside-7-O-$\alpha$-L-rhamnoside (2), kaempferol 3-O-$\beta$-glucosyl($1{\rightarrow}2$)-$\alpha$-rhamnoside-7-O-$\alpha$-rhamnoside (3) and quercetin 3-O-$\beta$-glucosyl($1{\rightarrow}2$)-$\alpha$-rhamnoside-7-O-$\beta$-rhamnoside (4) on the basis of spectroscopic data. The result showed that 1 is the most active compound in the DPPH and ABTS radical scavenging test. Conclusions : Isolated Compounds from the shoot of Aralia elata showed anti-oxidative effect.

• Natural Product Sciences
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• v.10 no.5
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• pp.244-247
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• 2004

The inhibitory effects of the leaves of Eucalyptus darylmpleana (Myrtaceae) on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical was examined. The scavenging effect of the ethyl acetate fraction of Eucalyptus darylmpleana leaves on DPPH radical was stronger than the other fractions, and further purified by silica gel and Sephadex LH-20 column chromatography. 3,4-Dihydroxybenzoic acid, gallic acid, quercetin, quercetin $3-O-{\alpha}-_L-rhamnoside$, quercetin $3-O-{\beta}-_D-glucoside$ and quercetin 3-O-rutinoside were isolated and elucidated by spectroscopic data. Among these components, gallic acid and quercetin $3-O-{\alpha}-_L-rhamnoside$ exhibited potent scavenging activities on DPPH radical with $IC_{50}$ values of 6.02 and $5.54\;{\mu}M$, respectively.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.277-286
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• 2022

Schizophragma hydrangeoides (S. hydrangeoides) is a vine endogenous to Jeju Island and Ulleungdo, where it grows attached to the foothills and rock surfaces. Previous research has mostly focused on the whitening effect of S. hydrangeoides leaf extract. In this study, we investigated S. hydrangeoides leaf extract further, and detected four phytochemicals in the extract: chlorogenic acid, quercetin-3-O-glucosyl-(1-2)-rhamnoside, quercetin-3-O-xylosyl-(1-2)-rhamnoside, and quercitrin. We pretreated human dermal fibroblast (HDFn) cells with previously established concentrations of the four compounds for 1 h before ultraviolet A (UVA) irradiation. Among the four compounds, quercetin-3-O-glucosyl-(1-2)-rhamnoside (Q-3-GR) best inhibited matrix metalloproteinase-1 (MMP-1) levels. Thus, we investigated the protective effects of Q-3-GR on photoaging and its underlying mechanisms. Q-3-GR significantly reduced MMP-1 production and inhibited MMP-1 protein expression in UVA-irradiated HDFn cells. Furthermore, Q-3-GR increased procollagen type I production and protein expression. Q-3-GR exerted its anti-photoaging effects by downregulating the mitogen-activated protein kinase/ activator protein-1 signaling pathway, and upregulating the transforming growth factor-β/Smad signaling pathway. Thus, S. hydrangeoides leaf-derived Q-3-GR is a potential potent cosmetic ingredient for UV-induced skin aging.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.442-446
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• 2006

Cedrela sinensis is a broadleaf tree that is widely cultivated in Korea and China. It was used for treating enteritis, dysentery, and skin itch in oriental medicine. In this study, three major flavonoids, kaempferol-3-O-rhamnoside (1), quercetin-3-O-rhamnoside (2), and quercetin-3-O-glucoside (3), were isolated from the leaf of Cedrela sinensis. The biological activities of these compounds were tested by inhibitory activity of matrix metalloproteinases-2 (Type IV collagenase) method together with a cytotoxicity and a apoptosis test against human cancer cell lines.

• Korean Journal of Medicinal Crop Science
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• v.13 no.6
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• pp.250-254
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• 2005

The contents of flavonol glycosides, $kaempferol-3-O-{\beta}-D-glucoside$(1), $kaempferol-3-O-{\beta}-D-glactoside$ (2), $kaempferol-3-O-{\beta}-D-rhamnoside$ (3), $quercetin-3-O-{\beta}-D-glucoside$ (4) and $quercetin-3-O-{\alpha}-D-rhamnoside$ (5) in the houseleeks controlled by night-break, day-length control, and temperature during overwintering were determined to be compared with those in wild one. The contents of the flavonol glycosides 1-5 in the houseleeks were decreased roughly with warming during overwintering, and increased with longer light duration under the day-length control experiments. While warming functioned negatively on the production of the flavonol glycosides in the houseleek, longer light irradiation did positively during overwintering.

• Herbal Formula Science
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• v.12 no.1
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• pp.255-262
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• 2004

The inhibitory effect of the aerial parts of Fagopyrum esculentum on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical was examined. The n-butanol fraction from the methanol extract of title plant showed stronger inhibitory effect than other fractions on DPPH radical. Two flavonoids were isolated from n-butanol fraction having the potent activity and elucidated as quercetin-3-O-${\alpha}$-L-rhamnoside and quercetin-3-O-rutinoside on the basis of spectral evidence. The $IC_{50}$ values of these compounds on DPPH radical were 6.56 ${\mu}M$ and 8.37 ${\mu}M$, respectively.

• Korean Journal of Pharmacognosy
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• v.19 no.2
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• pp.93-96
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• 1988

Three flavonoids were isolated from Epimedium koreanum and identified as quercetin(1), $anhydroicaritin-3-O-{\alpha}-rhamnoside(2)$ and icariin(3) by spectroscopic methods. The former two compounds are the first isolation from this plant.

• Natural Product Sciences
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• v.8 no.4
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• pp.147-151
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• 2002

In the course of our work on anti-platelet constituents from plants, eight phenolic compounds, $({\pm})-syringaresinol$ (1), 4-hydroxybenzaldehyde (2), 4-hydroxybenzoic acid (3), vanillic acid (4), 4-hydroxy cinnamic acid (5), quercetin 3-O-rhamnoside (6), rutin (7), and quercetin $3-(2^G-rhamnosylrutinoside)$ (8) were isolated from the methanol extract of the leaves of Magnolia obovata. The compounds were identified based on the spectroscopic data. Compound 2, 3, 5, 6, 7 and 8 were isolated for the first time from genus Magnolia. 1 and 6 showed same order of inhibitory potencies as acetylsalicylic acid (ASA) to rat platelet aggregation induced by all the stimulators tested. The remaining six compounds showed only mild effects.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1859-1864
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• 2018

Synthesis of flavonoid glycoside is difficult due to diverse hydroxy groups in flavonoids and sugars. As such, enzymatic synthesis or biotransformation is an approach to solve this problem. In this report, we used stepwise biotransformation to synthesize two quercetin bisglycosides (quercetin 3-O-glucuronic acid 7-O-rhamnoside [Q-GR] and quercetin 3-O-arabinose 7-O-rhamnoside [Q-AR]) because quercetin O-rhamnosides contain antiviral activity. Two sequential enzymatic reactions were required to synthesize these flavonoid glycosides. We first synthesized quercetin 3-O-glucuronic acid [Q-G], and quercetin 3-O-arabinose [Q-A] from quercetin using E. coli harboring specific uridine diphopsphate glycosyltransferase (UGT) and genes for UDP-glucuronic acid and UDP-arabinose, respectively. With each quercetin 3-O-glycoside, rhamnosylation using E. coli harboring UGT and the gene for UDP-rhamnose was conducted. This approach resulted in the production of 44.8 mg/l Q-GR and 45.1 mg/l Q-AR. This stepwise synthesis could be applicable to synthesize various natural product derivatives in case that the final yield of product was low due to the multistep reaction in one cell or when sequential synthesis is necessary in order to reduce the synthesis of byproducts.