• Biomedical Science Letters
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• v.25 no.3
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• pp.288-292
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• 2019

In vitro antimicrobial activities of hot water extracts of Camellia sinensis (L.) O. Kuntze, for carbapenem-resistant Enterobacteriaceae (CRE) were compared to commonly used conventional antimicrobial agents. CRE was not only resistant to imipenem, meropenem or ertapenem, but also to various antimicrobial agents, such as amikacin (> $128{\mu}g/mL$). The hot water extracts of Camellia sinensis (L.) O. Kuntze had the lowest MIC ($0.06{\sim}0.5{\mu}L/mL$) of the carbapenem-resistant E. coli, K. pneumoniae, and Enterobacter spp. tested, and it was possible more potent than various conventional antimicrobial agents. Synergistic combinations of the extract with used commonly antimicrobial agents might even improve its antimicrobial chemotherapy property.

• Natural Product Sciences
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• v.3 no.1
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• pp.11-13
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• 1997

From the methanolic extract of defatted tender leaf of Camellia sinensis a new 4-hydroxy angular furocoumarin $C_{12}H_8O_5$, m.p. $212^{\circ}C$, was isolated using high-speed counter-current chromatographic technique. The structure of the compound was established as 4-hydroxy-2'-methoxy angular furocoumarin on the basis of physical methods viz. $^1H$ NMR, $^{13}C$ NMR and MS.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2007.11a
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• pp.366.1-366.1
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• 2007

• 한국약용작물학회:학술대회논문집
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• 2007.11a
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• pp.303.1-303.1
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• 2007

• Proceedings of the Plant Resources Society of Korea Conference
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• 2007.11a
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• pp.367.1-367.1
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• 2007

• Advances in Traditional Medicine
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• v.8 no.2
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• pp.171-177
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• 2008

Epigallocatechin 3-gallate (EGCG), one of the major catechins of tea, was isolated from the decaffeinated, crude methanolic extract of Indian green tea (Camellia sinensis L. O. Kuntze) using chromatographic techniques. EGCG was then screened for antidiarrhoeal activity against 30 strains (clinical isolates) of V. cholerae, which is a well known Gram negative bacillus functioning as the pathogen of cholera. V. cholerae strains like V. cholerae 69, 71, 83, 214, 978, 1021, 1315, 1347, 1348, 569B and ATCC 14033 were inhibited by EGCG at a concentration of $25\;{\mu}g/ml$ whereas V. cholerae 10, 522, 976 were even more sensitive, being inhibited at $10\;{\mu}g/ml$ level. However, V. cholerae DN 16, DN 26, 30, 42, 56, 58, 113, 117, 564, 593, 972 and ATCC 14035 were inhibited at $50\;{\mu}g/ml$ level of EGCG. Only four strains were inhibited at $100\;{\mu}g/ml$. In this study the isolated compound was found to be bacteriostatic in its mechanism of action. In the in vivo experiment using the rabbit ileal loop model two different dosages of EGCG ($500\;{\mu}g/ml$ and $1,000\;{\mu}g/ml$) were able to protect the animals when they were challenged with V. cholerae 569B in the ileum.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.63-63
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• 2019

Tea plant (Camellia sinensis (L.) O. Kuntze) has been cultivated widely in many developing Asian, African, and South American countries, where it is the most widely consumed beverage in the world next to water. It has critical importance to understand the genetic diversity and population sturcutre for effective collection, conservation, and utilization of tea germplasm. In this study, 410 tea accessions collected from South Korea were analyzed using 21 SSR markers. Among 410 tea accessions, 85.4% (310 accessions) accessions were collected from Jeollanam-do. A total of 286 alleles were observed, and the genetic diversity and evenness were estimated to be averagely 0.79 and 0.61, respectively, across all the tested samples. Using discriminant analysis of principal components, the four clusters were detected in 410 tea accessions. Among them, cluster 1 showed higher frequency of rare alleles (less than 1%) than other clusters. Using calculation of the index of association and rbaD value, each cluster showed a clonal mode of reproduction. The result of AMOVA showed that most of the variation observed was within populations (99%) rather than among populations (1%). Our results might contribute to provide data about genetic diversity for the conservation of tea germplasm and for future breeding programs.

• Korean Journal of Plant Tissue Culture
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• v.24 no.3
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• pp.129-135
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• 1997

Morphogenetic responses were investigated by culturing embryo and leaf explants of Korean wild type tea plant, Camellia sinensis (L.) O. Kuntze. Induction of direct somatic embryogenesis as well as adventitious and/or axillary shoots was obtained from mature zygotic embryo cultures on Murashige and Skoog (MS) basal medium having 5 to $20\mu\textrm{M}$cytokinin a lone. Morphogenetic response was decreased dramatically by the addition of auxins tested. One hundred percent of induced and isolated shoots formed roots after four weeks of culture on half-strength MS or quarter-strength Schenk and Hildebrandt (SH) media supplemented with $10\mu\textrm{M}$indole-3-butyric acid (IBA). Immature zygotic embryos were shown to be a suitable explant for embryogenic callus formation in the presence of 2, 4-dichlorophenoxyacetic acid(2, 4-D) in basal medium. Mature zygotic embryo originated leaves were used to test their ability for mophogenesis by incorporating plant growth regulators such as IBA, naphthyl-1-acetic acid (NAA), and 6-benzylaminopurine (BAP). Apparently, the morphogenetic responses of the cultured explant sources on the types and/or levels of plant growth regulators tested were observed visually.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2012.05a
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• pp.11-11
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• 2012

차나무(Camellia sinensis (L.) O.Kuntze)는 열대, 아열대, 온대지역에서 자라는 교목 또는 관목의 영년생 상록수이다. 차는 초기 약효에 의하여 이용하기 시작하였으나 현대에 이르러 그 독특한 풍미로 인하여 전 세계 인구의 절반 이상이 음용하는 중요한 기호음료이다. 강우량이 많고 따듯한 곳에서 생육이 왕성한 차나무는 현재 한국, 중국, 일본, 동남아시아의 온난지역, 남아메리카, 아프리카 및 러시아 등지에 이르는 넓은 지역에 분포하고 있다. 2,000년의 역사를 가지는 한국의 차산업은 주로 경남과 전남, 전북, 제주 등지에서 재배 생산되고 있다. 1970년대 이후 생활수준의 향상과 함께 점차적으로 수요가 늘어나면서 생산량은 1970년 55톤에서 1993년 617톤, 2010년 3,586톤으로 약 65배 이상 증가하였다. 차산업은 찻잎을 원료로 한 생활용품 등 다양한 가공품의 생산과 문화산업, 관광산업까지 포함하는 고부가가치 작목으로 매년 재배 면적이 크게 증가하였다. 최근에는 재배면적의 급속한 증가와 수입확대, 소비환경의 변화로 산지 재고가 증가하는 등 녹차 재배 농가의 어려움이 가중되고 있어 향후 수급 불균형이 우려되고 있다. 세계의 차 무역량은 연간 약 160만 톤, 재배면적은 약 256만 ha, 생산량은 약 320만 톤에 달한다. 아직까지는 수입 녹차에 대한 높은 관세율(514%)의 보호 아래 있지만, 중국이나 일본 등에 비해 가격, 품질, 상품개발 면에서 뒤떨어져 있는 실정이다. 또한 현재 외국에서 수입되고 있는 다양한 차들이 소비자의 기호에 영향을 미치고 있으며 특히 가격 경쟁력이 떨어지는 상황이다. 향후 차시장의 전면적인 개방에 대비하기 위해서는 경쟁력 있는 수출전략과 함께 국내 산업을 안정적으로 성장시키기 위한 전력을 모색해야한다. 주요 차생산국의 다원은 15도 이내의 경사지에 생성되어 있으나 30도 내외의 경사지도 다원 조성에 무리가 없다. 우리나라는 약 200만ha의 경사지를 포함하고 있어 차재배지 확대에 무한한 잠재력을 가지고 있다.

• Korean Journal of Food Science and Technology
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• v.39 no.2
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• pp.181-188
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• 2007

This study examined the effects of green tea extract supplementation (500 or 1,000 mg/kg b.w. per day) in conjunction with an atherogenic diet (10% coconut oil (w/w), 0.1% cholesterol) on plasma lipid composition, regression of pre-existing foam cells, and on the mRNA levels of hepatic HMG-CoA reductase and LDL receptor. Compared to groups fed only with the atherogenic diet, the addition of green tea extract to atherogenic diet-fed groups significantly down-regulated plasma triglyceride and total cholesterol levels, dose-dependently. Supplementation of 1,000 mg/kg b.w. of green tea extract with the atherogenic diet induced significant up-regulation of both HMG-CoA reductase and LDL receptor messenger RNA levels in liver as compared to the group receiving green tea extract supplementation at 500 mg/kg b.w. The F1B hamsters fed the atherogenic diet had greater foam cell accumulation compared to those fed a normal diet, or the atherogenic diet supplemented with green tea extract. Regression of fatty streak lesions was achieved by atherosclerosis in fat- and cholesterol-fed hamsters and this effect was associated with down-regulation of plasma cholesterol and up-regulation of hepatic LDL receptor expression.