• 한국식품조리과학회지
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• 제4권1호
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• pp.53-57
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• 1988

국산차 기술개발을 위한 기초 자료를 얻고자 국내산 및 스리랑카제품의 특성에 대하여 분석한 결과는 다음과 같다. 1. 국산 홍차는 스리랑카 홍차에 비하여 섬유함량이 50% 높은 반면 탄닌 및 카페인함량은 크게 낮았다. 탄닌의 경우 3.5배, 카페인함량은 50%의 차이를 나타내었다. 또한 회분, 조지방, 조단백질의 함량은 두 제품간에는 큰 차이가 없었다. 2. 스리랑카 홍차에서는 P 3,000ppm, K 15,000ppm, Mg 1,400ppm, Ca 4,000ppm, Cu 22ppm, Cr 21ppm 및 Zn 45ppm으로 국산 홍차보다 높은 함량이었으며, 국산홍차에서는 F 225ppm, Mn 1,950ppm, Fe 265ppm, Sr 6ppm 및 Al 4,100ppm으로 스리랑카 홍차보다 높은 함량이었다. Pb와 Cd는 양 제품에서 검출되지 않았다. 3. 국산 홍차에서는 6종류의 유기산이 분리·동정되었는데 quinic acid와 gallic acid의 함량이 높았다. 스리랑카 홍차에서는 8종류의 유기산이 동정되었으며 shikimic acid, citric acid 및 quinic acid가 주요 유기산이었다. 4. Sucrose의 함량은 스리랑카 홍차보다 국산 홍차가 2.5배 높았다. 5. 홍차의 특수성분인 theaflavin, thearubigin, theobromine의 함량은 스리랑카 홍차에서 높은 경향을 나타내었다.

• Genomics & Informatics
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• 제14권3호
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• pp.96-103
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• 2016

The influenza A (H1N1) virus, also known as swine flu is a leading cause of morbidity and mortality since 2009. There is a need to explore novel anti-viral drugs for overcoming the epidemics. Traditionally, different plant extracts of garlic, ginger, kalmegh, ajwain, green tea, turmeric, menthe, tulsi, etc. have been used as hopeful source of prevention and treatment of human influenza. The H1N1 virus contains an important glycoprotein, known as neuraminidase (NA) that is mainly responsible for initiation of viral infection and is essential for the life cycle of H1N1. It is responsible for sialic acid cleavage from glycans of the infected cell. We employed amino acid sequence of H1N1 NA to predict the tertiary structure using Phyre2 server and validated using ProCheck, ProSA, ProQ, and ERRAT server. Further, the modelled structure was docked with thirteen natural compounds of plant origin using AutoDock4.2. Most of the natural compounds showed effective inhibitory activity against H1N1 NA in binding condition. This study also highlights interaction of these natural inhibitors with amino residues of NA protein. Furthermore, among 13 natural compounds, theaflavin, found in green tea, was observed to inhibit H1N1 NA proteins strongly supported by lowest docking energy. Hence, it may be of interest to consider theaflavin for further in vitro and in vivo evaluation.

• Archives of Pharmacal Research
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• 제29권9호
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• pp.786-794
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• 2006

We observed the suppressive effect of a powder formulation of African black tea extract prepared from the leaves of Camellia sinensis on type 2 non-insulin dependent diabetic mice, $KK-A^y/TaJcl$. Black tea extract significantly showed suppressive effect of the elevation of blood glucose on oral glucose tolerance test of 8 week-old $KK-A^y/TaJcl$ mice (p<0.05). Long-term treatment with black tea extract showed significant suppression of post-prandial blood glucose and obesity (p<0.05). The weight of the intestine of mice treated with black tea extract was significantly reduced (p<0.05). From these results, African black tea used in this study showed a suppressive effect on the elevation of blood glucose during food intake and the body weight.

• Preventive Nutrition and Food Science
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• 제12권1호
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• pp.7-10
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• 2007

Theaflavins (TF) and thearubigins (TR) were separated from Korean microbially fermented tea leaves. Contents of TF (74.4 $\mu$M/g) and TR (37.2%) were higher than reported for black tea fermented by oxidase. Antioxidant activities of TF, TR and EGCG were analyzed and protective effects of COS-7 cells against copper and cadmium-induced toxicity were investigated. TF and TR exhibited good inhibition rates of about 85$\sim$90% for antioxidant and scavenging activities of free radicals and protected COS-7 cells against apoptosis or damage caused by stress, such as cadmium and copper-oxidative injury, free radicals etc. These results indicate that TF, TR and EGCG have antioxidant and scavenging activities against free radicals and protect COS-7 cells from Cu, Cd induced injury.

• BMB Reports
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• 제36권1호
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• pp.66-77
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• 2003

Tea is one of the most popular beverages consumed in the world and has been demonstrated to have anti-cancer activity in animal models. Research findings suggest that the polyphenolic compounds, (-)-epigallocatechin-3-gallate, found primarily in green tea, and theaflavin-3,3'-digallate, a major component of black tea, are the two most effective anti-cancer factors found in tea. Several mechanisms to explain the chemopreventive effects of tea have been presented but others and we suggest that tea components target specific cell-signaling pathways responsible for regulating cellular proliferation or apoptosis. These pathways include signal transduction pathways leading to activator protein-1 (AP-1) and/or nuclear factor kappa B(NF-${\kappa}B$ ). AP-1 and NF-${\kappa}B$ are transcription factors that are known to be extremely important in tumor promoter-induced cell transformation and tumor promotion, and both are influenced differentially by the MAP kinase pathways. The purpose of this brief review is to present recent research data from other and our laboratory focusing on the tea-induced cellular signal transduction events associated with the MAP kinase, AP-1, and NF-${\kappa}B$ pathways.

• 한국식생활문화학회지
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• 제24권3호
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• pp.308-314
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• 2009

In this study, we examined the composition of catechins, theaflavins and alkaloids in leaves during processing to fermented black tea, which is produced by withering, roll breaking, and fermentation of Korean Yabukida tea plant. In addition, we determined the optimal conditions for the production of fermented black tea. The average moisture content in fresh leaves was 70.85%, which dropped to 3.07% in fermented black tea at the last stage of production. When the leaves were analyzed by HPLC, seven types of catechins, four types of theaflavins and three types of alkaloids were identified. The levels of catechins, theaflavins, and alkaloids were then evaluated after being processed into fermented tea. From these experiments, we found that the level of theaflavins, which determines the property of the tea, increased during fermentation. This effect resulted from the change in EGCG, ECG, EGC, EC during the process of fermentation. We also found that the maximal amount of theaflavins was created after 1-2 hours of fermentation. Thus, our results imply that the best condition for producing fermented black tea would be to ferment for 1-2 hours.

• 한국식품조리과학회지
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• 제4권1호
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• pp.47-52
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• 1988

녹차의 품종, 채엽시기, 가공방법별에 따라 13종류의 한국산 녹차시료를 조제하고 이들 시료의 이화학적 성질을 측정한 결과는 다음과 같다. 1. 수활, 회분, 가용성 고형분 및 조지방 함량은 대체적으로 품종, 차엽의 채취시기 및 가공방법의 상위에 따른 큰 차이점은 나타나지 않았지만 조단백질의 경우에서는 삽목 Yabukida 품종 1번 차의 볶음과 찐 것에서 각각 30.8%, 31.3%이던 것이 2, 3번차로 갈수록 점차 감소하여 4번차의 경우에서는 각각 18.8%, 16.0% 이었다. 이러한 경향은 다른 품종에서도 유사한 경향을 나타내었다. 품종별에 따른 변화도 크게 나타났다. 조섬유에서는 채엽시기에 따라 증가하는 경향을 나타내었다. 2. 표면색도는 볶음 차보다 찐 차가 보다 밝은 녹황색을 띄며 채엽시기가 늦을수록 밝은 황색을 나타내었다. 또한 클로로필함량은 찐 차의 경우가 볶은 차보다 높았고, 채엽시기에 따라 감소의 경향을 보였으나 삽목 Yabukida 4번 차의 경우에서는 증가하였다. 3. 탄닌의 함량은 볶음의 경우 채엽시기가 늦을수륵 증가하였지만 찐 차의 경우 그런 경향이 나타나지 않았으며 theaflavin과 thearubigin 함량은 평균하여 각각 0.07% 및 2.27%이었고 산화중합물비는 평균 0.22이었다. 4. Methylxanthine류에서는 caffeine이 주성분으로 94∼98%를 차지하였으며 볶음차의 caffeine 함량이 높았다. 베니호마래의 caffeine 함량은 다른 품종보다 낮았다. 5. 녹차의 환원당은 0.1% 내외로 거의 일정하였으며 유리당의 경우 삽목 Yabukida가 다른 품종에 비해서 sucrose 함량이 높게 나타났다. 6. 녹차중의 유기산은 succinic, malic, shikimic, citric, quinic, gallic, oxalic 및 malonic acid의 8종류이었으며 이중 quinic acid의 함량이 높았다. 삽목 Yabukida 품종에서는 채엽시기가 빠른 녹차에서는 malic acid 함량이 매우 낮은 반면 oxalic acid는 채엽시기가 늦을수록 감소하여 미량으로 검지되었다.

• 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.

• Genomics & Informatics
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• 제18권4호
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• pp.43.1-43.13
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• 2020

The coronavirus disease 2019 is a contagious disease and had caused havoc throughout the world by creating widespread mortality and morbidity. The unavailability of vaccines and proper antiviral drugs encourages the researchers to identify potential antiviral drugs to be used against the virus. The presence of RNA binding domain in the nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could be a potential drug target, which serves multiple critical functions during the viral life cycle, especially the viral replication. Since vaccine development might take some time, the identification of a drug compound targeting viral replication might offer a solution for treatment. The study analyzed the phylogenetic relationship of N protein sequence divergence with other 49 coronavirus species and also identified the conserved regions according to protein families through conserved domain search. Good structural binding affinities of a few natural and/or synthetic phytocompounds or drugs against N protein were determined using the molecular docking approaches. The analyzed compounds presented the higher numbers of hydrogen bonds of selected chemicals supporting the drug-ability of these compounds. Among them, the established antiviral drug glycyrrhizic acid and the phytochemical theaflavin can be considered as possible drug compounds against target N protein of SARS-CoV-2 as they showed lower binding affinities. The findings of this study might lead to the development of a drug for the SARS-CoV-2 mediated disease and offer solution to treatment of SARS-CoV-2 infection.

• 한국식품영양학회지
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• 제28권5호
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• pp.766-773
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• 2015

This study analyzes the chemical composition of green tea, white tea, yellow tea, oolong tea and black tea with respect to extraction temperature and time. The optimum extraction conditions for these teas were determined by assessing the chemical composition of tea brewed at different temperature (50, 60, 70, $80^{\circ}C$) and extraction times (1, 3, 5, 10 minute). Catechins contents were the largest at 5 minutes and generally declined by 10 minutes. Green tea catechins contents were highest when brewed at $70^{\circ}C$ and besides other teas a change of the trend variation at 70 and $80^{\circ}C$. These temperatures did not extract theaflavins in green tea. Extract temperature and time did not significantly affect theaflavins content of white tea, yellow tea, and oolong tea. Black tea, however, was noticeably dependent on extract conditions, which were most effective at $70^{\circ}C$, brewed for 5 minutes. Caffeine content of green tea, yellow tea, and oolong tea was highest at 5 minutes, but temperature did not appear to affect the content. White tea and black tea caffeine content was highest when brewed at $70^{\circ}C$ for 5 minutes. Theobromine content of green tea, yellow tea, oolong tea, and black tea did not show major differences between the study times or temperature, though the content in white tea increased with higher temperatures when brewed for 5 minutes. The extraction of phenolic compounds increased until 5 minutes, and showed not further increase at 10 minutes. Antioxidant capacity of green tea, white tea, and yellow tea were maximized at $70^{\circ}C$ for 5 minutes or $80^{\circ}C$ for 3 minutes, while oolong and black tea were reached maximum antioxidants at $70^{\circ}C$ for 5 minutes. In general, to optimize the beneficial chemical content of brewed tea, a water temperature of $70^{\circ}C$ for 5 minutes is recommended.