• 생약학회지
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• 제10권2호
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• pp.41-53
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• 1979

A 6', 8a-bonded catechin dimer was synthesized by action of phenoloxidase on 2mol (+)-catechins. The same dimer and other two dimers which are also 6', 8a-bonded were isolated from the fresh cortex of Quercus robur. The 4, 8a-bonded and the etherified 4, 8a-bonded dimers were isolated from it. It was discussed about the meaning of the enzymatically produced 6', 8a-bonded dimers in plant cell. The isolated dimers are as following: 1. 6', 8a-bonded dimers: (+)-catechin-(+)-catechin-6', 8a-dimer(IX), (+)-catechin-(+)-gallocatechin-6', 8a-dimar (XIII), (+)-gallocatechin-(+)-catechin-6', 8a-dimer(XIV). 2. 4, 8a-bonded dimers: (+)-catechin-(+)-catechin-4, 8a-dimer(X), (-)-epicatechin-(+)-catechin-4, 8a-dimer (XI), (+) -galloatechin-(+)-catechin-4, 8a-dimer (XII). 3. 4,8a-bonded dimers with ether linkage: etherified(+)-catechin-(+)-catechin-4, 8a-dimer (XV), etherifid (+)-catechin-(+)-gallocatechin-4, 8a-dimer (XVI), etherified (+)-gallocatechin-(+)-catechin-4, 6a-dimer (XVII).

• 한국식품위생안전성학회지
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• 제16권2호
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• pp.117-124
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• 2001

녹차의 주요 성분인 catechin은 항돌연변이, 항종양, 항균, 항바이러스 활성 및 콜레스테를 저하, 혈압 상승 억제, 해독, 방사선 차단 작용 등과 같은 다양한 생물학적 작용들이 보고되고 있다. 최근 환경 오염의 급증으로 인한 오존층의 파괴로 지표에 도달하는 자외선이 증가됨에 따라 피부노출 위험이 증가하고 있다. 따라서 피부암의 발생이 증가하는 추세이며 역학적 및 실험실적 연구에서 자외선 조사가 가장 큰 원인이라고 보고되고 있다. 이에 본 연구는 catechin이 UVB에 의해서 손상된 피부조직에 미치는 영향을 연구하였고 광발암과정에서 catechin의 억제효과가 apoptosis에 어떤 영향을 주어 작용하는지를 in vivo hairless mouse skin에서 연구하였다. 녹차잎에서 추출한 catechin을 hairless mouse를 대조군, catechin을 처리한 군, 자외선을 처리한 군, catechin과 자외선을 처리한 군으로 나누었으며 catechin의 농도는 3mg/mouse로 피부에 도포한 후 자외선을 100 mJ/$ extrm{cm}^2$ 조사하였다. 자외선에 의한 피부조직에 미치는 catechin의 영향을 H&E stain을 실시하여 확인하였고, apoptosis에 미치는 catechin의 보호효과를 알아보기 위해 DNA laddering 형성 여부와 TUNEL assay로 확인하였으며 western blot을 이용하여 apoptoic activity와 관련된 단백질인 p53연구하였다. 또한 자외선에 의한 세포증식에 미치는 catechin을 영향을 bromodeoxyuridine(BrdU) 면역염색방법을 이용하여 살펴보았다. 본 연구결과 자외선에 의하여 피부는 진피층의 교원섬유의 증가가 정상피부보다 2~3배 비후되었고, 염증세포의 침윤과 섬유화세포 등이 관탈되었으며 표피층은 두꺼워졌으나 상피세포가 소실되어 1~2층으로 되었다. UVB조사와 catechin을 2주간 처리한 후의 mouse의 피부는 표피층이 9~12층으로 이루어져 있었고, 세포의 핵은 과염색성을 보이며 커져있어 손상된 표피층 상피세포가 재생되고 있음을 확인하였다. Apoptosis에 미치는 결과에서 UVB 조사군은 apoptosis의 대표적 특징인 DNA fragmentation이 관찰되었고, UVB와 catechin을 처리한 군에서는 생성되지 않아 뚜렷한 보호효과를 나타내었다. TUNEL assay를 실시한 결과 UVB군과 catechin 군을 비교하였을 때 UVB+catechin군에서 apoptotic cells이 유의성 있는 차이(p<0.05)를 보였다. Apoptosis 관련 단백질인 p53발현을 살펴본 결과 대조군과 비교해볼 때 UVB군과 UVB와 catechin을 처리한 군간에서는 차이가 없었다. 자외선에 의한 세포증식에 미치는 catechin의 영향을 살펴본 결과 BrdU에서는 UVB군과 UVB+catechin군을 비교하였을 때 UVB+catechin군에서 BrdU 세포수가 유의성 있는(p<0.05) 감소를 보였다. 본 연구 결과에 의해 녹차의 주요성분인 catechin은 자외선에 의해 유도되는 세포증식 및 apoptosis를 억제하고, 세포손상, 세포증식 및 apoptosis를 억제시킴을 확인하였다.

• 한국식품영양과학회지
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• 제12권3호
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• pp.284-288
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• 1983

Ascorbic acid (AsA)와 Catechin의 혼합용액에서 AsA의 안정성을 조사할 목적으로 각각의 농도 및 pH별 혼합용액을 조제하여 가열하는 동안 AsA와 catechin의 함량변화를 조사하였다. AsA의 손실은 각 혼합구 모두 가열 시작 10분 동안에 가장 많았으며 catechin의 혼합에 의해 촉진되었으나 혼합비율이 높은 경우가 낮은 것에 비하여 AsA의 손실은 적었다. Catechin의 손실도 가열 시작 10분 동안에 가장 컸으며 AsA의 농도가 높고 catechin의 농도가 낮을수록, AsA의 농도가 낮고 catechin의 농도가 높을수록 작았다. AsA의 안정성은 catechin의 함유비가 낮을 경우에는 pH 4pH 5>pH 6 순으로 pH 4 에서 높았다.

• 동의생리병리학회지
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• 제19권6호
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• pp.1580-1584
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• 2005

Antioxidative activities of catechin from green tea extracts were examined by the methods of 1,1-Diphenyl-2-picrylhydrazyl (DPPH) electron donating ability, hydroxy scavenging activity and the inhibitory effect on xanthine oxidase activity. The resulted demonstrated the fact that Catechin one (containing Green tea extracts plus catechin 51%) of green tea extracts product showed at 65.5% in electron donating activity on the DPPH. The electron donating ability on the DPPH of Catechin one was increased to 10% than purified catechin. Catechin one showed the activity at 64.5% in scavenging activity using hydroxy radical method. To the Catechin one provided to increase the hydroxy scavenging activity up to 3 fold. Inhibitory effects of the catechin one measured with xanthine oxidase method was 6.5%. Although the antioxidative activity of catechin (98% purified) was lower than that of Catechin one (containing Green tea extracts plus catechin 51%) in same catechin concentrations ($5{\mu}g$, respectively). Therefore, we may suggest that Catechin one can be used as a functional food additive possessing the potent antioxidative activity.

• 한국재료학회지
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• 제33권11호
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• pp.458-464
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• 2023

In order to develop catechin patches for skin regeneration at wound sites, patches with varying concentrations of catechin and chitosan were manufactured. An optimal composition ratio was determined by adjusting the drug release rate and amount, to maximize efficiency. The catechin used in this study was extracted from green tea leaves using a solvent/ultrasonication method, and its characteristics were confirmed through Fourier transform-infrared spectroscopy (FT-IR) and high-performance liquid chromatography (HPLC) analyses. Patches were prepared with different concentrations of catechin and chitosan, and various properties were analyzed using techniques such as FT-IR, water contact angle analysis, and UV-Vis spectroscopy. It was observed that as the chitosan concentration increased, the release of catechin slowed down or almost ceased. A patch manufactured with 1.5 mg/cm² of catechin at a 1 % chitosan concentration exhibited a high initial release rate over 24 h and demonstrated cellular biocompatibility. Consequently, these patches, with tailored release characteristics based on the concentrations of chitosan and catechin, hold promise for use as drug delivery systems in wound healing applications.

• Journal of Nutrition and Health
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• 제34권8호
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• pp.881-886
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• 2001

The purpose of this study was to Investigate the effects of green tea catechin on changes of mineral contents in chronic cadmium-poisoned rats. Sprague-Dawley male rats weighing 100 $\pm$ 10g were randomly assigned one of normal group and three cadmium poisoned groups. Cadmium groups were classified to catechin free diet(Cd-0C group), 0.25% catechin diet(Cd-0.25C group) and 0.5% catechin diet(Cd-0.5C group) according to the levels of catechin supplement. Animals were raised for 20 weeks. Cadmium was supplied in drinking water which contained 50ppm Cd$^{2+}$. Effects of catechin were analyzed on changes of mineral contents in chronic cadmium poisoned rats by determining the calcium accumulation in bones, blood, urine and faces and phosphorus In blood and urine. Cd-poisoning inducted the decrease of red blood cell(RBC), white blood cell(WBC), contents of blood hemoglobin and hematocrit, but the levels of those indices were increased by catechin supplementation. The contents of tibia and femur in Cd-0C group was significantly lower than in normal group, but those of catechin supplemetation group was similar to normal group. The calcium contents of urine and faces were higher in Cd-poisoned groups than in normal group, but they was lowered by catechin supplementation. The phosphorus contents of blood and urine in Cd-0C group was significantly lower than in normal group, but that of catechin supplementation group was similar to normal group. Catechin supplementation improved the calcium metabolism in chronic cadmium poisoned rats by increasing the contents of minerals such as calcium and phosphorus in blood and femur and by lowering the urinary and fecal calcium.m.

• Journal of Nutrition and Health
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• 제33권7호
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• pp.725-732
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• 2000

The purpose of this study was to investigate the effects of green tea catechin on renal dysfunction and blood presure change in chronic cadmium poisoned rats. Sprague-Dawley male rats weighing 100$\pm$10g were randomly assigned to one normal group and three cadmium poisoned groups. Cadmium groups were classified to catechin free diet(Cd-0C group) 0.25% catechin diet(Cd-0.25C group) and 0.5% catechin diet(Cd-0.5C group) according to the levels of catechin supplement. Animals were raids for 20weeks. Cadmium were supplied as drinking water of 50ppm Cd2+ Morphological changes shown through a light microscope and an electro-microscope revealed the mitochondria and tubule epithelial cell edema in Cd -0C group but they were alleviated in catechin supplementation. The urinary $\beta$2-microglobulin that measured to observe the glomerular injury were higher in Cd-poisoned groups than in normal group but they was lowered by catechin supplementation. Glomerular filtration ratios(GFR) in Cd-poisoned groups were significantly lower than in normal group but that of catechin supplementation group was similar to normal group. This suggested that catechin protected the kidney from the functional damage. Angiotensin converting enzyme(ACE) activity and blood pressure(BP) in Cd-poisoned groups were significantly higher than in normal group. Heart rate was tended to increase in Cd-poisoned groups. The results indicate that green tea catechin supplementation on chronic cadmium-poisoned rats normalized the renal dysfunction and blood pressure system.

• Journal of Nutrition and Health
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• 제34권4호
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• pp.384-392
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• 2001

The purpose of this study was to investigate the effects of green tea catechin on the cadmium accumulation in body, cadmium excretion and detoxification functions in chronic cadmium poisoned rats. Sprague-Dawley male rats weighing 100$\pm$10g were randomly assigned to one normal group and three cadmium poisoned groups. Cadmium groups were classified to catechin free diet (Cd-0C group), 0.25% catechin diet(Cd-0.25C group) and 0.5% catechin diet(Cd-0.5C group) according to the levels of catechin supplement. Animals were maintained on 0, 0.25 and 0.5% catechin diets for 20 weeks and simultaneously administered 50ppm Cd(sup)2+ dissolved in the drinking water. Body weight, food intakes and food efficiency ratio in Cd-0C group was lower than the normal group. The accumulation of cadmium in rat liver, kidney, and blood was reduced by catechin supplementation. The excretion of cadmium in urine and feces was increased by catechin supplementation. The metallothionein(MT) contents in liver and kidney were increased in all cadmium groups compared with that of normal group. The ratios of cadmium absorption and retention ratios were significantly decreased in catechin supplementation groups. Accordingly, catechin supplementation resulted to an excretion of cadmium in urine and feces and a lowered accumulation of cadmium in liver and kidney by increasing methallothionein synthesis that led to the significant decrease in cadmium absorption and retention ratios.(Korean J Nutrition 34(4) : 384~392, 2001)

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3443-3447
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• 2011

The spectroscopic behavior of catechin (5,7,3',4'-tetrahydroxyflavan-3-ol), has been studied in the presence and the absence of air using UV-vis absorption spectrophotometry and fluorescence spectroscopy. The UV-vis absorption spectrum of catechin shows a very sharp and strong absorption maximum peak at 275 nm in deaerated water. New absorption maximum peaks appeared in aerated water, as well as in basic aqueous solution, caused by the oxidation of catechin. The absorbances in the UV-vis absorption spectrum of catechin decreased when the solution was left in the dark for a long time. The fluorescence emission spectrum of catechin after a long time period differs markedly from that in freshly prepared solution; the fluorescence maxia shifted as time passes after adding catechin to the solutions. When the deaerated basic catechin solutions were left in the dark for a long time, their fluorescence quantum yields were found to be nearly zero. This suggests that the oxidized catechin molecules were seen to have slowly undergone successive chemical reactions in basic buffer solution.

• Archives of Pharmacal Research
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• 제12권3호
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• pp.219-222
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• 1989

Cartechin and catechin glycoside named uldavioside A were isolated from the Korean folk medicine Ulmus davidiana. Based on chemical and physicochemical evidences, their structure have been determined as (+) catechin (1) and (+)-catechin-5-0-$\betha$ D-apiofuranoside (2).