• Archives of Pharmacal Research
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• v.10 no.3
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• pp.169-172
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• 1987

From the leaves of Rhododendron brachycarpum, rhododendrin, grayanotoxin I and guaijaverin were isolated and characterized by spectral data.

• Journal of the Korean Wood Science and Technology
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• v.37 no.2
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• pp.171-176
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• 2009

The chemical constituents of Acer komarovii Pojark. which belongs to Aceraceae has never been reported. The bark of A. komarovii was extracted with 70% aqueous acetone, and the concentrated extract was successively partitioned with n-hexane, dichloromethane, ethyl acetate and $H_2O$. From the ethyl acetate soluble fraction, four compounds were isolated by the repeated Sephadex LH-20 and RP C-18 column chromatography. From the results of spectroscopic methods including FAB-MS, 1D and 2D NMR, the structures of the compounds were determined as quercetin (1), guaijaverin (2), hirsutrin (3) and hyperin (4). These compounds (1-4) have not been reported in this tree yet.

• Journal of Plant Biology
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• v.36 no.3
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• pp.297-300
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• 1993

Six flavonoid compounds from the ethyl acetate fraction of Machilus thunbergii leaves were identified by HPLC. Separation by reversed phase chromatography on u-Bondapak C18 column was achieved by isocratic elution. The contents of the major flavonoids, guaijaverin and quercitrin were about 0.48% (w/w) and 0.98% (w/w) for the methanol extract, respectively.

• Korean Journal of Pharmacognosy
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• v.39 no.2
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• pp.146-149
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• 2008

From the leaves of Angelica keiskei (Umbelliferae), luteolin, protocatechuic acid, guaijaverin, hyperoside and cynaroside were isolated and characterized by spectral data. Luteolin and protocatechuic acid showed potent DPPH radical scavenging activity.

• Journal of Sericultural and Entomological Science
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• v.41 no.3
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• pp.123-128
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• 1999

Chemical characteristics of mulberry syncarp were investigated six mulberry varieties, including Subongppong, Daeryukppong, Kuksang 20, Chongilppong, Cataneo and a wild variety. Water content of mulberry syncarp was 78.5∼85.0%and sugar degree of Kuksang 20 was the highst among six varieties. Anthocyanin content of Chongilppong mulberry syncarp was 282.42mg% and Kuksang 20 was lower 13% than Chongilppong mulberry fruit. Also Daeryukppong and wild variety were higher 11% respectively. GABA content of wild variety was higher than other varieties. In flavonol glyconsides analysis, rutin content was the highest in Cataneo, isoquercitrin content was in a wild variety, guaijaverin and quercitrin content was the highst in Chongilppong respectively.

• Archives of Pharmacal Research
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• v.28 no.5
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• pp.529-533
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• 2005

In the course of searching for hepatoprotective agents from natural products, six compounds were isolated from the MeOH extract of the leaves of Juglans sinensis, as guid ed by their DPPH free radical scavenging activity. The structures were determined as juglanoside B (1), quercetin 3-O-${\alpha}$-L-arabinofuranoside (avicularin, 2), quercetin 3-O-${\alpha}$-L-arabinopyranoside (guaijaverin,3), quercetin 3-O-${\alpha}$-L-rhamnopyranoside (quercitrin,4), (+)-catechin (5) and quercetin 3-O-${\beta}$- D-galactopyranoside (hyperin,6). Compounds 2-6 showed significant DPPH free radical scavenging effects. An evaluation for the hepatoprotective activity of the isolated compounds on drug-induced cytotoxicity was conducted, and compounds 1, 2, and 5 showed protective effects against nitrofurantoin-induced cytotoxicity, and compound 5 also exhibited a moderate protective effect on amiodarone-induced cytotoxicity in Hep G2 cells.