• 한국식품과학회지
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• 제38권1호
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• pp.5-9
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• 2006

본 연구는 차에 함유되어 있는 특유의 정미성분으로 methylxantin류, catechin류 및 theaflavin류의 총 13종의 화합물을 HPLC를 이용한 동시분석법을 확립함과 동시에 이 분석법을 이용하여 한국에서 사판되고 있는 녹차, 홍차 및 우롱차에 함유되어 있는 주요 성분을 분석하였으며 그 결과는 다음과 같다. HPLC분석조건은 역상(ODS)column을 이용하여 acetonitrile: 20 mM 인산완충액의 solvent 중 acetonitrile의 농도를 처음 단계 7%에서 최종 40%까지 단계적으로 변화시켜 분당 1mL씩 용출시켜 분석하였다. Column 온도는 효과적으로 각 성분을 분리시키기 위하여 정확하게 $30^{\circ}C$로 설정하였으며 파장은 270 nm에서 분석하였다. 또한 차에 함유되어 있는 methylxantin류, catechin류 및 theaflavin류의 총 13종의 화합물을 분석한 결과, 한 시료당 90분이 소요되었으며 재현성과 정량성이 뛰어나 13종의 화합물이 완전하게 분리되었다. 시판 녹차, 홍차, 우롱차를 분석한 결과, 녹차와 우롱차는 2종류의 methylxantin류와 7종류의 catechin류는 검출되었으나 홍차에서 검출된 4종류의 theaflavin류는 전혀 나타나지 않았다. 이러한 결과는 차의 품질 관리 및 소비자의 차 선택에 있어 중요한 기초자료가 될 것으로 사료된다.

• 한국식품영양과학회지
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• 제24권1호
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• pp.154-159
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• 1995

Inhibition of xanthine oxidase by tea extracts obtained from non-fermented tea(steamed green tea and roasted green tea), semi-fermented tea(oolong tea) and fermented tea(black tea) were investigated. The crude catechin fraciton had a hgher inhibitory effect against xanthine oxidase, and the effect was increased with the addition of tea extracts. Their inhibitory effect were hardly influenced until extracted three times with hot water. According to the investigation of catechins in the crude catechin fraction obtained from tea extracts, (-)-epicatechin-(EC), (-)-epicatechin gallate(ECg). (-)-epigallocatechin(EGC) and (-)-epigallocatechin gallate(EGCg) were 80.1$\mu\textrm{g}$/mg 113.5$\mu\textrm{g}$ /mg, 186.3$\mu\textrm{g}$/mg and 367.7$\mu\textrm{g}$/mg in steamed green tea, and 75.6$\mu\textrm{g}$/mg, 114.7$\mu\textrm{g}$/mg, 193.7 $\mu\textrm{g}$/mg and 381.9$\mu\textrm{g}$/mg in roasted green tea, and 69.4$\mu\textrm{g}$/mg, 110.0$\mu\textrm{g}$/mg, 127.1$\mu\textrm{g}$.mg and 464.9$\mu\textrm{g}$/mg in oolong tea, and 78.1$\mu\textrm{g}$/mg, 171.8$\mu\textrm{g}$/mg, 80.7$\mu\textrm{g}$/mg and 51.4$\mu\textrm{g}$/mg in black tea, respectively. Order of the content of these catechins was (-)-EGCg>(-)-EGC>(-)-ECg>(-)-EC in steamed green tea, roasted green tea and oolong tea, and was (-)-ECg>(-)-EGC>(-)-EC>(-)-EGCg in black tea. Also the concentration of catechins was hardly influeced until extracted three times. The inhibition ratio of xanthine oxidase by autherntic catechins was hardly influenced until extracted three times. The inhibition ratio of xanthine oxidase by authentic catechins was 94.9% and 87.6% by addition of 5.0$\mu\textrm{g}$/ml of (-)-EGCg and (-)-ECg, respectively. the inhibitors of xanthine oxidase were supposed to be due to (-)-ECg and (-)-EGCg in tea polyphenol compounds.

• Preventive Nutrition and Food Science
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• 제12권3호
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• pp.135-140
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• 2007

Antibacterial activities of the major phenolic components from Camellia sinensis L. were investigated against several pathogenic microorganisms including Gram-positive strains like Staphylococcus aureus ATCC 29213 and Streptococcus pyogens 308A; and Gram-negative strains like Escherichia coli ATCC 25922, Escherichia coli 078, Pseudomonas aeruginosa 9027, and Enterobacter cloacae 1321E. The MIC values demonstrate that both (-)-epicatechin and (-)-epigallocatechin were more considerably toxic against Staphylococcus aureus ATCC 29213 than the other two catechins like (-)-epicatechingallate and (-)-epigallocatechin-3-gallate. (-)-Epicatechingallate and (-)-epigallocatechin-3-gallate were most inhibitory against Escherichia coli ATCC 25922. As a result, (-)-epicatechin showed predominant antibacterial activities among tea varieties. The contents of major polyphenolic components such as four catechins, theaflavin, and quercetin were different according to fermentation processes. The total contents of four catechins were ranged from 13.81 to 1.33%, with (-)-epigallocatechin-3-gallate being dominant among tea varieties; theaflavin was found the characteristic pigment in fully-fermented black tea.

• Food Science and Biotechnology
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• 제17권5호
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• pp.1016-1020
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• 2008

Parameters of soluble solids, amino acids, catechins, and color difference of 24 green tea samples from China and Korea were determined. The levels of soluble solids, amino acids, total catechins, and infusion lightness in tea samples from Korea were higher than those from China. Concentrations of epigallocatechin galate and epigallocatechin in teas from China were higher than tea samples from Korea. Geographical origin of teas from the 2 countries was discriminated using parameters of infusion lightness, gallocatechin, and total catechins and applying principal component analysis.

• 약학회지
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• 제45권1호
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• pp.101-107
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• 2001

Green tea catechins (GTC) and its major component, (-)-epigallocatechin gallate (EGCG) were studied for their protective effects against reactive oxygen species (ROS)-induced oxidative stress. GTC and EGCG skewed the strong antioxidative effects on the lipid peroxidation of ethyl linolate with Fenton's reagent and free radical scavenging effect to DPPH radical generation. They also protected $H_2O$$_2$- or KO$_2$-induced cytotoxicity in CHL cells or mouse splenocytes. These results indicate that GTC and EGCG are capable of protecting the lipid peroxidation, flee radical generation and cytotoxicity induced by ROS. The mechanism of inhibition in ROS-induced cytotoxicity may be due to their antiofidative and free radical scavenging properties. Therefore, GTC and EGCG may be useful chemopreventive agents by protecting the free radical generation which are involved in cancer and aging.

• 한국작물학회지
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• 제40권6호
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• pp.775-781
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• 1995

국산녹차에 있어서 보건적 효능과 관련된 특수성분의 유엽시기 및 제다법에 따른 변화를 조사한 결과는 다음과 같다. 수용성 펙틴은 후기유엽기에 점차적으로 증가를 보였으며 평균함량은 봉산리 녹차가 2.05% 부춘리 녹차가 1.84%이었다. 생엽에 대한 제다엽의 변화는 증다법 22.8%, 부초법 17.9% 증가하였다. 총엽록소는 후기유엽기로 갈수록 증가하여 1번 유엽기에서 5번 유엽기까지 봉산리는 233mg%에서 334mg%로, 부춘리는 198mg%에서 4번유엽기 까지 331mg%로 증가하였으나 5번 유엽기에 다소 감소를 보였다. 평균함량은 봉산리 평균 293mg%, 부춘리 평균 275mg%이었으며, 엽록소 a : 엽록소 b는 봉산리 평균 70.0:30.0, 부춘리 평균 67.3:32.7이었고 제다법에 따라 엽록소 a와 엽록소 b의 감소 정도에 차이가 있었다. 총 아미노산 함량은 봉산리 2,156mg%, 부춘리 평균 1,723mg%로 갈수록 큰 폭으로 감소를 보였다. 카페인은 후기유엽기에서 다소 적은 함량을 보였으나 부춘리는 3번 유엽기에 2.86%까지 증가를 보이다 감소하였다. 평균 카페인함량은 봉산리가 2.033%, 부춘리가 2.620%이었다. 카테친류는 후기유엽기로 갈수록 증가를 보였으나 봉산리의 경우 4번 유엽기 이후 급격히 감소하였다. 평균 카테친함량은 봉산리가 11.52%, 부춘리가 14.05%이었으며 유리형의 카테친은 봉산리 평균 35.59%, 부춘리 평균 42.73%, easter형 카테친은 봉산리 평균 58.09%, 부춘리 평균 44.47%이었다. 카테친류 및 카페인의 식용시 용출량은 침출온도가 $65^{\circ}C$에서 85$^{\circ}C$로 높을수록, 침출시간이 3분에서 9분으로 길수록 증가하였으며, 85$^{\circ}C$, 9분 침출시 카테친류는 89.3%, 카페인은 97.3%가 용출되었다.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2001년도 10주년 기념 국제학술 심포지움 및 추계학술대회
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• pp.38-38
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• 2001

• 한국염색가공학회지
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• 제20권2호
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• pp.75-82
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• 2008

The optimum extraction conditions of green tea used for a bath were investigated for application to textiles. The stability of the extracts and content of active ingredients were analyzed as well. The extraction was more effective in water and methanol than in ethanol. The optimum extraction temperature was determined as $80^{\circ}C$ in water and $60^{\circ}C$ in methanol. The solid extracts were obtained about 7% in water and 9% in methanol on the weight of dry green tea. The extracts were more stable in acid and neutral conditions than in alkaline region. From the analysis of contents of active ingredients, about 20% of effective catechins was appeared to be contained in the extract solid, which was thought to be available for application to textiles.

• Plant Biotechnology Reports
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• 제3권1호
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• pp.95-101
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• 2009

Tea leaves are major source of catechins—antioxidant flavonoids. Dihydroflavonol 4-reductase (DFR, EC 1.1.1.219) is one of the important enzymes that catalyzes the reduction of dihydroflavonols to leucoanthocyanins, a key ''late'' step in the biosynthesis of catechins. This manuscript reports characterization of DFR from tea (CsDFR) that comprised 1,413 bp full-length cDNA with ORF of 1,044 bp (115-1,158) and encoding a protein of 347 amino acids. Sequence comparison of CsDFR with earlier reported DFR sequences in a database indicated conservation of 69-87% among amino acid residues. In silico analysis revealed CsDFR to be a membrane-localized protein with a domain (between 16 and 218 amino acids) resembling the NAD-dependent epimerase/dehydratase family. The theoretical molecular weight and isoelectric point of the deduced amino sequence of CsDFR were 38.67 kDa and 6.22, respectively. Upon expression of CsDFR in E. coli, recombinant protein was found to be functional and showed specific activity of 42.85 nmol $min^{-1}$ mg $protein^{-1}$. Expression of CsDFR was maximum in younger rather than older leaves. Expression was down-regulated in response to drought stress and abscisic acid, unaffected by gibberellic acid treatment, but up-regulated in response to wounding, with concomitant modulation of catechins content. This is the first report of functionality of recombinant CsDFR and its expression in tea.

• 한국응용과학기술학회지
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• 제30권4호
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• pp.761-769
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• 2013

하동지역에서 생산되는 잎 녹차(우전, 세작, 중작, 대작)에 함유되어 있는 catechin류, alkaloid류 및 theanine를 HPLC를 이용하여 분석을 함과 동시에 녹차 추출물을 이용하여 총 페놀 물질과 항산화능을 측정하였다. Catechin류와 alkaloid류, theanine, 총 페놀 화합물의 함량은 물 추출물 보다 80% 알코올 추출물에서 더 높았다. 총 catechin과 alkaloid의 함량은 80% 에탄올로 추출한 우전(172.33 mg/g, 30.80 mg/g)에서 가장 높았다. Theanine의 함량도 80% 에탄올 추출물에서 높았고 55.36에서 37.48 mg/g의 범위였다. 녹차의 총페놀 화합물은 우전에서 가장 높았고, DPPH법, FTC법 및 TBA법을 이용한 항산화 활성 측정에서도 우전에서 높은 결과를 나타내었다.