• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.2
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• pp.83-87
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• 2000

The five phenolic compounds of peony root were isolated by Sephadex LH-20 column chromatography. Their chemical structures were identified by spectroscopic methods (UV, FT-IR, FAB-MS and $^1H$ .&^13C$-NMR). The complete structures of these compounds were elucidated to be (+)-taxifolin-3-0-$\beta$-D-glucopyranoside, benzoic acid, gallic acid, (-)-epicatechin and (+)-catechin. The concentrations of five phenolic compounds in the peony root of three Korean cultivars (Youngchonjakyak, Euisungjakyak and Jomjakyak) were determined by reverse-phase HPLC. The constituents concentration in Youngchonjakyak were generally higher than in Euisungjakyak and Jomjakyak. The concentrations of (+)-taxifolin-3-O-$\beta$-D-glucopyranoside, benzoic acid, gallic acid, (-)-epicatechin and (+)-catechin in three different cultivars were ranged 0.23-0.52%, 0.20-0.30%, 0.26-0.28%, 0.09-0.12% and 0.34-0.63%, respectively.

• Applied Biological Chemistry
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• v.41 no.4
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• pp.265-269
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• 1998

Several flavonoid dimers were isolated and elucidated from the bark of Korean pine tree (Pinus densiflora). One of them was postulated to be a compound, epicatechin $(4{\rightarrow}7)$ 5,8,3',4'-tetrahydroxy-(2R,3R)-flavan-3-ol, whose structural determination was carried out by diverse NMR techniques.

• Preventive Nutrition and Food Science
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• v.10 no.2
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• pp.118-121
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• 2005

Methanol extracts were prepared from loquat leaves (2 kg) and successively fractionated with hexane, chloroform, ethyl acetate, butanol, and water solvents. The ethyl acetate fraction exhibited the highest antioxidative and, antimicrobial activities. Therefore, the ethyl acetate fraction was purified and a chemical structure was identified by $^1H$ and $^{13}C-NMR$ spectra, FT-IR and EI/MS spectroscopies. The isolated antioxidative and antimicrobial substance was identified as epicatechin.

• Journal of Korean Society of Forest Science
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• v.103 no.1
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• pp.113-121
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• 2014

From the bark of Euonymus japonica, ten compounds were isolated by column chromatography and identified as follows. The structures were determined as : (-)-epicatechin, (-)-epigallocatechin, vanillic acid, 2,4-dimethoxyphenol-1-glucoside, 2, 4, 6-trimethoxyphenol-glucoside, 5-caffeoylquinic acid, 4-caffeoyuinic acid, 3, 4-dicaffeoylquinic acid, 3, 5-dicaffeoylquinic acid, and 1, 5-dicaffeoylquinic acid.

• Biomolecules & Therapeutics
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• v.27 no.2
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• pp.145-151
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• 2019

Methamphetamine (METH) acts strongly on the nervous system and damages neurons and is known to cause neurodegenerative diseases such as Alzheimer's and Parkinson's. Flavonoids, polyphenolic compounds present in green tea, red wine and several fruits exhibit antioxidant properties that protect neurons from oxidative damage and promote neuronal survival. Especially, epicatechin (EC) is a powerful flavonoid with antibacterial, antiviral, antitumor and antimutagenic effects as well as antioxidant effects. We therefore investigated whether EC could prevent METH-induced neurotoxicity using HT22 hippocampal neuronal cells. EC reduced METH-induced cell death of HT22 cells. In addition, we observed that EC abrogated the activation of ERK, p38 and inhibited the expression of CHOP and DR4. EC also reduced METH-induced ROS accumulation and MMP. These results suggest that EC may protect HT22 hippocampal neurons against METH-induced cell death by reducing ER stress and mitochondrial damage.

• Journal of the Korean Wood Science and Technology
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• v.34 no.6
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• pp.61-71
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• 2006

This study was carried out to investigate chemotaxonomical correlation an d the chemical constituents of domestic Quercus sp. leaves. The leaves of Q. mongolica, Q. aliena, Q. serrata, Q. acutissima, Q. dentata and Q. variabilis were collected in the experimental forest of Kangwon National University. The combined extracts were successively fractionated with n -hexane, methylene chloride and ethyl acetate using a separation funnel. A portion of the ethyl acetate and $H_2O$ soluble materials of each species were chromatographed on a Sephadex LH-20 column using various aqueous MeOH and EtOH-hexane as washing solvents. Spectrometric analysis such as NMR and MS, including TLC, were performed to characterize the structures of the isolated compounds. Gallic acid, (+)-catechin, (-)-epicatechin, (+)-gallocatechin, kaempferol, astragalin, astragalin-6"-O-gallate, isoquercitrin, isoquercitrin-6"-O-gallate and myricetin were isolated from Q. mongolic a leaves. Gallic acid, kaempferol and quercetin were characterized from Q. acutissima leaves. Gallic acid, (+)-catechin, (-)-epicatechin, (+)-gallocatechin, (-)-epigallocatechin, kaempferol, quercetin, guajaverin and tamarixin were identified from Q. dentata leaves. Gallic acid, (+)-catechin, (-)-epicatechin, kaempferol, quercitrin, isoquercitrin and myricetin were purified from Q. serrata leaves. Gallic acid, (+)-catechin, astragalin, astragalin-6"-O-gallate and isoquercitrin were isolated from Q. variabilis leaves. Gallic acid was isolated from all the leaves and could be a taxonomic index on Quercus spp..

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.513-518
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• 2005

Capillary electrophoresis (CE) method was developed to determine (+)-catechin and (-)-epicatechin contents in grape seed ethanol extract. CE separation was achieved using 100 mM phosphate and borate buffer at pH 6.0 as background electrolyte and fused silica capillary with 50 microns x 375 microns O.D. (effective length 20.0cm) maintained at $25^{\circ}C$. The applied voltage was 10kV, and detection was performed by DAD at 210 nm, Two catechins were well separated within 6 min with repeatability of <0.8% RSD for migration time and <2.0% RSD for peak area, and correlation coefficients higher than 0.994 were obtained from 58.0 to 174.0 mg/L with detection limit of 0.035 mg/L. Separated compounds were successfully determined. CE method was easy to handle and showed good reproducibility. CE method was compared with conventional coloring and HPLC methods, and main advantages of CE method were low amount of sample required, simple pre-sample treatment, good recovery rate, and short analysis time.

• Journal of Sericultural and Entomological Science
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• v.42 no.1
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• pp.6-9
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• 2000

This study was performed to investigate the catechins which separated from mulberry leaf. The Epicatechin contents in mulberry leves was 1.21${\pm}$0.05 $\mu\textrm{g}$/mg ethylacetate fraction. epigalocatechingallte contents WAS 3.56 $\mu\textrm{g}$/mg ethylacetate fraction. The cathechins (epicatechin and epigalocate-chingallate) separated from mulberry leaf was shown a strong activity to growth inhibition by the concentration of 5 mg/disc on the Clostridium perfringens.

• YAKHAK HOEJI
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• v.37 no.5
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• pp.476-482
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• 1993

For the investigation of medicinal resources in Crataegus species, the present study was carried out to evaluate the pharmaco-constituents in the leaves of Crataegus Pinnatifida var. psilosa (Rosaceae). Fruits has folk medicine in Korea. From the $Et_{2}$O fraction of MeOH extract, a new compound, apigenin-8-C-(6"-acetyl)-$\beta$-D-glucopyranoside, named psilosin and three known compounds, ursolic acid, phytosterol complex and (-)-epicatechin were isolated and identified on the basis of their physico-chemical properties and spectroscopic evidences (UN, IR, NMR and mass etc.) in comparison with authentics, respectively.

• Korean Journal of Pharmacognosy
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• v.27 no.3
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• pp.219-223
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• 1996

From the rachis of Cedrela sinensis A. Juss., methyl gallate, quercitrin, bis-(p-hydroxyphenyl)ether, adenosine, isoquercitrin, rutin, (+)-catechin and (-)-epicatechin were isolated and characterized by spectral data.