• Journal of the Korean Wood Science and Technology
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• 제37권2호
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• pp.164-170
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• 2009

The bark of Acer barbinerve was extracted with 70% aqueous acetone and the organic extracts were concentrated to small volume using rotary evaporator and then fractionated successively with n-hexane, dichloromethane, ethyl acetate and water. The chromatographic separation of ethyl acetate soluble fraction led to the isolation of five phenolic compounds. By means of spectroscopic method, the structures of these compounds were identified to methyl gallate (1), methyl gallate-4-O-${\beta}$-D-glucose (2), (+)-catechin (3), (-)-epicatechin (4) and (-)-epicatechin-3-O-gallate (5). These compounds (1-5) have not been reported in this plant yet.

• 한국식품위생안전성학회지
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• 제11권2호
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• pp.77-82
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• 1996

Green tea catechins(GTC) were studied for its inhibitory effect on human platelet aggregation in vitro, for its antithrombotic effect in mice in viro, and bleeding and clotting time in rats. The catechins were isolated and purified from green tea, which were composed of (-)-epigallocatechin gallate, (-)-epigallocatechin, (-)epicatechin gallate and (-)-epicatechin, GTC produced a potent inhibition of human platelet aggregation in a dose-dependent manner against the stimulants such as ADP, collagen, epinephrine and ristocetin n vitro. GTC also prevented death due to the formation of pulmonary thrombosis by platelet aggregates in mice in a dose-de-pendent manner in viro. GTC increased the bleeding time, whole blood clotting time and plasma clotting time in rats, too. These results suggest that GTC is a promising antithrombotic agent.

• 생약학회지
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• 제36권1호통권140호
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• pp.50-55
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• 2005

Reactive oxygen species (ROS) are continuously produced at a high rate as a by-product obtained in the aerobic metabolism. A major portion of living organisms has defense system as superoxide dismutase or catalase against damage produced by ROS. Several lines of evidence provided that ROS appears to cause to develop aging and various diseases. Spatholobus suberectus Dunn has been known as a Korean folk medicine for promoting blood circulation and relieving blood stasis as anemia. In this study, we have investigated the antioxidant activities of Spatholobus suberectus Dunn in order to find the antioxidant substances from natural products. For various antioxidant experiment, the major antioxidant component was isolated from EtOAc extract of Spatholobus suberectus Dunn. This compound was identified as (-)-epicatechin by chemical and physical analysis.

• 생약학회지
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• 제31권3호
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• pp.357-363
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• 2000

The root of Actinidia arguta was extracted with methanol and the methanol extract was suspended in $H_2O$ and successively partitioned with n-hexane, $CH_2Cl_2$, EtOAc and n-BuOH. Repeated column chromatographic separation of the EtOAc extract resulted in the isolation of two flavonoids (compounds 2 and 3) and two triterpenes (compounds 1 and 4) and $CH_2Cl_2$, extract to afford three lignans (compounds 5-7). Their structures have been established by spectroscopic, means to be (+)-tormentoside(1), (-)-catechin(2), (-)-epicatechin(3), (+)-uscaphic $acid-28-O-[\beta}-D-glucopyranoside$(4), (+)-pinoresinol(5), (+)-medioresinol(6), and (-)-syringaresinol(7).

• Natural Product Sciences
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• 제9권2호
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• pp.105-108
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• 2003

During our research program to find DNA strand-scission agents from higher plants, the MeOH extracts of the stems of Mucuna birdwoodiana Tutcher. (Leguminosae) exhibited the most potent activity with an $IC_{50}$ value of $4.9\;{\mu}g/ml$. Thus, detailed laboratory investigation was performed, and led to the isolation of known compounds, $({\pm})$-catechin (1) and (-)-epicatechin(2) as active principles. Compounds 1 and 2 showed significant activity of DNA strand-scission with $IC_{50}$ values of 10.8 and $7.5\;{\mu}g/ml$, respectively (positive control, bleomycin: $IC_{50}\;3.3\;{\mu}g/ml$.

• Journal of the Korean Wood Science and Technology
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• 제24권2호
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• pp.81-93
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• 1996

To elucidate the structure of procyanidin in Korean red pine (Pinus densiflora S. et Z.), bark, the extractives were extracted with acetone-water mixture(7:3, v/v) from inner bark of Korean red pine. The extracts separated three fractions which were extracted by liquid-liquid extraction. The extracting solvents were chloroform and ethyl acetate and water. The part of ethylacetate soluble was chromatographed by liquid chromatography. The ethylacetate soluble portion yielded four natural procyanidin dimers, two known epicatechin-($4{\beta}{\rightarrow}6$)-catechin, catechin-($4{\alpha}{\rightarrow}8$)-catechin and two unknown catechin-($4{\beta}{\rightarrow}6$)-catechin and conformational isomer of epicatechin-($4{\alpha}{\rightarrow}6$)-catechin. The additional catechins was also isolated. The structures of these procyanidins were elucidated by their $^{13}C$-NMR spectra.

• Archives of Pharmacal Research
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• 제24권4호
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• pp.292-296
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• 2001

Three prolyl endopeptidase (PEP) inhibitors were isolated from the methanolic extract of green tea leaves. They were identified as (-)-epigallocatechin gallate, (-)-epicatechin gallate, and (+)-gallucatechin gallate with the $IC_{50}$ values of 1.42${\times}$$10^{-4}$mM, $1.02{\times}10^{-2}$mM, and $1.09{\times}10^{-4}$mM, respectively. They were non-competitive with a substrate in Dixon plots and did not show any significant effects against other serine proteases such as elastase, trypsin, and chymotrypsin, suggesting that they were relatively specific inhibitors against PER The isolated compounds are expected to be useful for preventing and curing of Alzheimer's disease.

• Journal of the Korean Wood Science and Technology
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• 제32권2호
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• pp.58-64
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• 2004

임산바이오매스 자원 이용의 일환으로 율추(栗皺) 열수추출물의 디에틸에테르 가용부의 HPLC 분석결과, 표준물질과의 retention time이 일치한 것을 RI detector로 얻어진 각 피크의 스펙트럼을 표준물질과 비교하고, 순도를 확인하는 방법으로 피크의 동정을 실시하였다. 피크의 동정 결과, phenolic acids와 aldehyde류로는 gallic acid, 3,5-dihydroxybenzoic acid, 2,4,6-trihydroxybenzoic acid, 그리고 protocatechualdehyde이었으며, flavonoids는 catechin과 epicatechin으로 모두 6종이 확인되었다.

• 한국수정란이식학회지
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• 제31권3호
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• pp.153-159
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• 2016

(-)-Epicatechin gallate (ECG) is a polyphenol compound of green tea exhibiting biological activities, such as antioxidant and anticancer effects. To examine the effect of ECG on porcine oocytes during in vitro maturation (IVM), oocytes were treated with 0-, 5-, 15-, and $25{\mu}M$ ECG. After maturation, we investigated nuclear maturation, intracellular glutathione (GSH) and reactive oxygen species (ROS) levels and subsequent embryonic development after parthenogenetic activation (PA) and in vitro fertilization (IVF). After 42 hours of IVM, the $5{\mu}M$ group exhibited significantly increased (p< 0.05) nuclear maturation (89.8%) compared with the control group (86.1%). However, the $25{\mu}M$ group observed significantly decreased (p< 0.05) nuclear maturation (83.5%). In intracellular maturation assessment the 5-, 15-, and $25{\mu}M$ groups had significantly increased (p< 0.05) GSH levels and decreased ROS levels compared with the controls. The 5- and $15{\mu}M$ group showed significantly increased (p< 0.05) embryo formation rates and total cell number of blastocysts after PA (18% and 68.9, 15% and 85.1 vs. 12% and 59.5, respectively) compared with controls. Although the $25{\mu}M$ group observed significantly lower blastocyst formation rates after PA (27.6% vs. 23.2%) than control group, the $5{\mu}M$ group showed significantly increased blastocyst formation rates after PA (37.2% vs. 23.2%) compared to the control group. Furthermore, the $5{\mu}M$ group measured significantly increased blastocyst formation rates (20.7% vs. 8.6%) and total cell number after IVF ($88.3{\pm}1.5$ vs. $58.0{\pm}3.6$) compared to the control group. The treatment of $5{\mu}M$ ECG during IVM affectively improved the porcine embryonic developmental competence by regulating intracellular oxidative stress during IVM.

• 한국식품저장유통학회지
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• 제16권5호
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• pp.747-753
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• 2009

본 연구에서는 국내외 주요 포도 가공품인 포도즙과 포도주의 일반분석 및 대표적인 폴리페놀화합물인 레스베라트롤, 쿼세틴 및 카테킨에 대한 함량 분석을 실시하였다. 한국산 포도제품과 외국산과의 색도, pH, 산도, 에탄올 함량 등은 제품, 품종, 제조국가 간에 유의적인 차이가 있었다. 유리당 조성은 포도즙과 포도주 사이에 큰 차이를 보였으며, 포도주 내에서도 통계적으로 유의한 결과를 나타났다. 레스베라트롤과 쿼세틴 함량에서는 국내산 포도즙 사이에 유의적인 차이를 발견할 수 있었으며 포도주가 포도즙보다 대체로 높은 경향이었다. 에피카테킨 함량 및 조성에서도 제품, 품종, 제조국가 간에 유의적인 차이가 인정되었다. 이러한 결과는 향후 포도 육종가, 재배 농가나 판매자들에게 유용한 정보가 될 것으로 기대된다.