• 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.

• 한국식품영양과학회지
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• 제21권4호
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• pp.386-389
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• 1992

녹차에 있어서 맛성분으로도 중요하고, 최근에는 그 약리작용의 연구과 활발히 연구되고 있는 catechin의 함량 분석을 국산 시판 녹차를 시료로 하여 시도하였다. 100mg의 시료 분말 녹차를 열수 출출한 후 $CHCl_3$를 가하여 시료 용액으로 부터 caffeine를 제거시키고 EtOAc를 가하여 catechin류를 추출 농축하여 5ml로 한 다음 $0.45\;\mu\textrm{m}$ membrane filter를 통과시킨 후 $2\;\mu\textrm{l}$을 HPLC에 주입시켰다. 4종류의 고순도 정량분석용 catechin류를 표준용액으로 한 검량선법에 의하여 시료중의 catechin 함량을 구하였다. 그 결과, EGCg의 함량(찐 1번차 : 7.54%, 볶은 1번차 : 7.88%)이 가장 많았고 EGC, ECg, EC의 순서로 그 함량이 감소하엿다. 수확시기가 늦은 2번차에서는 EGCg, ECg 와 같은 gallate는 증가하고 EGC는 약간 감소하는 경향을 나타내어 차의 맛에 영향을 주는것 같다.

• 한국미생물·생명공학회지
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• 제49권1호
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• pp.24-31
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• 2021

This study aimed to investigate the melanogenesis inhibitory activity of epicatechin-3-O-gallate (ECG) isolated from Polygonum amphibium L. ECG was isolated from the ethanol extract of P. amphibium L, and its chemical structure was determined using spectroscopic methods such as LC-ESI-MS, 1D-NMR, and UV spectroscopy. ECG inhibited the melanogenesis of B16F10 cells in a dose-dependent manner. Particularly, it decreased the melanin content by 27.4% at 200 µM concentration, compared with the control, in B16F10 cells, without causing cytotoxicity. It is noteworthy that the expression of three key proteins, including tyrosinase, tyrosinase-related protein-1 (TRP-1), TRP-2, and microphthalmia-associated transcription factor (MITF), involved in melanogenesis, is significantly inhibited by ECG. The ECG isolated in this study caused the inhibition of body pigmentation and tyrosinase activity in vivo in the zebrafish model. These results suggest that the ECG isolated from P. amphibium L. is an effective anti-melanogenesis agent.

• 생약학회지
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• 제30권4호
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• pp.397-403
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• 1999

Tyrosinase plays an important role in the process of melanin polymer biosynthesis. Therefore, the enzyme inhibitors have been of great concern as cosmetics to have skin-whitening effects on the local hyperpigmentation. During the search for new inhibitory compounds on melanin polymer biosynthesis from natural sources, MeOH extracts of 589 higher plants were tested for the inhibitory effect on tyrosinase activity by the muschroom tyrosinase assay in vitro. Among plants tested, the leaves of Cercis chinensis exhibited potent inhibitory effect on mushroom tyrosinase activity. Subsequently seven active compounds were isolated from the ethyl acetate soluble part of acetone extract of the leaves of C. chinensis by the activity guided fractionation monitoring the inhibitory effect on tyrosinase activity. Their chemical structures were identified as $kaempferol-3-0-{\alpha}-L-rhamnoside$, quercitrin, $myricetin-3-0-{\alpha}-L-rhamnoside$, myricetin-3-0-(2'-O-galloyl)- ${\alpha}$ -L-rhamopyranoside (desmanthin), (-)-epicatechin-3-0-gallate, (-)-epigallocatechin-3-0-gallate, and methyl gallate on the basis of the speculation of spectral data and chemical reaction. Among the flavonol rhamnosides, myricetin-3-0-(2'-O-galloyl)- -L-rhamnoside(desmanthin) showed most potent inhibitory effect on tyrosinase activity and the structure of B-ring in flavonol moiety was related to the activity. (-)-Epigallocatechin-3-O-gallate having pyrogallol group in flavan-3-ol moiety exhibited more potent inhibitory effect than (-)-epicatechin-3-0-gallate having catechol group in flavan-3-ol moiety on mushroom tyrosinase activity.

• 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.

• 한국식품영양과학회지
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• 제32권4호
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• pp.501-505
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• 2003

프로폴리스를 이용하여 새로운 기능성 식품을 개발하기 위하여 프로폴리스 원괴와 그 추출물의 화학성분에 대하여 조사하였다. 일반성분은 조지방 86.41%, 가용성 무질소물 7.32%, 조단백질 2.71%, 회분 1.05% 및 조섬유 0.20%로 나타났다. 프로폴리스에 함유되어 있는 주요 무기성분은 Na(120.40 mg%), Ca(115.40 mg%) 및 K(105.87 mg%) 순으로 나타났으며, Ca 함량은 알콜 추출물보다 물 추출물에서 높게 나타났다. 유리당은 총 3종이 분리, 동정되었으며, 그 중 sucrose가 152 mg%로 높게 나타났고, glucose 114 mg% 및 fructose 6 mg%로 함유되어 있었다. 프로폴리스에 함유되어 있는 주요 아미노산으로는 lysine, cystine 및 glutamic acid로 나타났으며, 그 함량은 각각 395.29 mg%, 267.66 mg% 및 248.14 mg%로 나타났다. 지방산은 총 8종이 분리되었으며, 주요 지방산으로는 oleic acid (51.89%), myristic acid (20.86%) 및 palmitic acid (20.28%)로 나타났다. 프로폴리스의 flavonol 화합물을 분석한 결과 myricetin, quercetin, apigenin 및 kaempferol이 주요 flavonol화합물로 나타났으며, 총 flavonoid 함량은 다른 추출물보다 50% 에탄올 추출물에서 가장 높게 나타났다. 프로폴리스에 함유되어 있는 polyphenol 성분들은 gallic acid, chlorogenic acid, catechin, epigallocatechin gallate, epicatechin 및 epicatechin gallate로 확인되었다.

• 한국식품저장유통학회지
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• 제13권4호
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• pp.421-426
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• 2006

제주산 건조녹차를 $55^{\circ}C$에서 15분간 추출하여 여과한 다음 PET병에 밀봉하여 $4^{\circ}C$ 저온과 실내 및 실외에 각각 보관하면서 보존안정성을 측정하였다 저장기간에 따라 L값은 거의 변화가 없었지만 a값이 감소하고 b값이 증가하면서 전체적인 색깔이 짙어졌으며, 실내에서 저장한 경우가 실외저장이나 저온저장보다 저장기간이 길어질수록 더 짙어졌다. 녹차추출물 중의 주요 카테킨류로는(-)-epigallocatechin, (-)-epigallocatechin gallate, epicatechin, (+)-catechin, epicatechin gallate순이었으며, EGC의 함량비율이 전체의 53.8%이었다. 총 카테킨 함량은 저온저장에서는 큰 차이가 없었지만, 실내 및 실외 저장한 경우에는 $148.87{\mu}g/mL$에서 14주일 후에는 각각 133.98, $141.87{\mu}g/mL$로 10%, 4.7%가 감소하였다. 카페인 함량은 저장조건에 관계없이 전체적으로 증가하였으며, 총 폴리페놀 함량은 저장조건 및 저장기간에 따른 차이가 크지 않았다. 전자공여능은 저장방법과 저장기간에 관계없이 60% 이상의 효과가 있었다. 아질산염 소거능은 pH 1.2에서 90% 이상으로 가장 높았으며, pH가 증가할수록 감소하다가 pH 6.0에서는 아질산염 소거효과가 없어졌다. 3개월 이상 경과하더라도 색깔, 폴리페놀성분, 항산화작용등의 변화가 크지 않았다. $95^{\circ}C$에서 10분간 살균으로 보관기간 중에 미생물의 증식이 인정되지 않아 저장안전성을 유지하는 것으로 판단되었다.

• 생약학회지
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• 제32권1호통권124호
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• pp.68-71
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• 2001

For the use of tannins in the whitening-effect cosmetics, inhibitory effect against tyrosinase activity was determined. Three condensed tannins including gallocatechin, gallocatechin 3',4'-di-O-gallate and epicatechin 3-O-gallate and three hydrolyzable tannins, 1,2,6-tri-O-galloyl-${\beta}$-D-glucose, 2,3-(S)-HHDP-D-glucose and pedunculagin showed 15-29% mild inhibitory effects against tyrosinase activity.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.212.2-212.2
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• 2003

In the course of searching for BACE1 (${\beta}$-secretase) inhibitors from natural products, the ethyl acetate soluble fraction of green tea, which was suspected to be rich in catechin content, showed potent inhibitory activity. (-)-Epigallocatechin gallate, (-)-epicatechin gallate, and (-)-gallocatechin gallate ware isolated with IC$\_$50/ values of 1.6${\times}$10$\^$-6/ M, 4.5${\times}$10$\^$-6/ M, and 1.8${\times}$10$\^$-6/ M, respectively. Seven additional authentic catechins were tested for a fundamental structure-activity relationship. (-)-Catechin gallate, (-)-gallocatechin, and (-)-epigallocatechin significantly inhibited BACE1 activity with IC$\_$50/ values of 6.0${\times}$10$\^$-6/ M, 2.5${\times}$10$\^$-6/ M, and 2.4${\times}$10$\^$-6/ M, respectively. (omitted)

• Advances in Traditional Medicine
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• 제4권4호
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• pp.267-273
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• 2004

Oxidative stress is associated with many kinds of chronic diseases. Antioxidants such as polyphenols are compounds that protect cells against the damaging effects of reactive oxygen species. Grape seeds are considered good resources of polyphenols, and grape seed extracts have a very strong antioxidant effect. In the present study, we established a simple gradient reverse-phase high performance liquid chromatography method to determine polyphenol content from three different grape seed resources. An ODS (2), $150\;{\times}\;3.2\;mm$ column has been employed, and six polyphenols have been determined: gallic acid, protochatechuic acid, (+)-catechin, (-)-epicatechin, procyanidin B2, and epicatechin gallate. Catechin and epicatechin were the main polyphenol compounds in all three extracts. The amount of procyanidin B2 was higher in Extract 1 (from a company of China), while Extract 2 (extracted in our lab) and Extract 3 (from a company of USA) contained higher proportions of epicatechin gallate. For the total polyphenol content, Extract 1 was much higher than that of Extract 2 and 3. The results suggest that the dietary dose of grape seed extracts from different resources should be adjusted according to polyphenol content.