• Title, Summary, Keyword: catechins

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Diagnostic FAB-MS Spectra of Green Tea Components (고속원자충격질량분석에 의한 녹차성분 검색)

  • Moon, Dong-Cheul;Lee, Jeong-Hee;Lee, Yong-Moon
    • YAKHAK HOEJI
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    • v.36 no.3
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    • pp.205-211
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    • 1992
  • A simple dignostic method using Fast Atom Bombardment mass spectrometry was applied to the characterization of green tea flavonols from the eluates of Sepahadex LH-20 column chromatography. From the ethyl acetate extracts, crude mixture of flavonol fraction(Fr.$1{\sim}4$) were separated by the stepwise gradient elution with 30, 45, and 60% aqueous acetone. Procyanidine B analogues were found to be typical constituents of Fr. 1. Main components of Fr. 2 were catechins and gallo-catechins. Fr. 3 contained mainly ester type compounds, catechin-gallates, gallocatechin-gallates with their analogues. Fr. 4 was contaminated with some phthalate esters.

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Rapid Separation and Indentification Method of Tea Catechins (녹차 중 카테킨류의 신속 분리 및 동정법)

  • Lee, Jeong-Hee;Lee, Yong-Moon;Moon, Dong-Cheul
    • Analytical Science and Technology
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    • v.5 no.3
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    • pp.333-338
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    • 1992
  • The tea tannins, epigallocatechin, epigallocatechin gallate, were successfully separated by a Sephadex LH-20 column by the acetone based gradient elution. Each fractions was collected by monitoring at 280nm. Purified fractions were directly characterized by fast atom bombardment mass spectrometry. Epigallocatechin and epigallocatechin gallate were identified and shown as low as 70% purity in the reversed phase column. This revised method is more advantageous than known methods in purity and rapidity.

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Biological Effects of Korean Puerariae Radix Catechins on the Liver Function in Rats Administrated with Ethanol

  • Lee, Chi-Ho
    • Preventive Nutrition and Food Science
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    • v.2 no.2
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    • pp.138-143
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    • 1997
  • Crude catechin extracts were prepared using ethyl acetate from Korean Puerariae Radix (PR) and their biological effects on the alcoholic liver damage were investigated in male Sprague-Dawley rats (6 weeks old). Ethanol (5g ethanol/kg body weight/day) administration was performed for 8 weeks and after ethanol consuming rats were treated with one or two% catechin extracts of diet for 8 weeks. At the end of experimental period, lipid hydroperoxides in liver were analyzed using a chemiluminescence-high performance liquid chromatography (CL-HPLC) method. Compared with control animals, ethanol consumed rats showed lighter body weights, lower ratios of liver/body weight, higher activities of GOT and GPT, and increased lipid hydroperoxide amount in liver. With one or two% catechin extracts treatment, GOT and GPT activities returned to normal ranges. Lipid hydroperoxide contents in liver of on or two% PR treated rats lowered to 20% or 25% respectively, compared with the levels of those ethanol consumed animals without catechin extracts treatment. Therefore, we concluded that on or two% PR crude catechins treatment could be effective for alcoholic liver damage caused by lipid peroxidation.

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Protective effect of green tea extract on doxorubicin induced cardiotoxicity in rats

  • Patil, Leena;Balaraman, R.
    • Oriental Pharmacy and Experimental Medicine
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    • v.5 no.2
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    • pp.137-143
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    • 2005
  • Doxorubicin induces oxidative stress leading to cardiotoxicity causing electrocardiogram abnormalities and increases in biomarkers associated with toxicity. Green tea extract (GTE) is reported to possess antioxidant activity mainly via its polyphenolic constituent, catechins. This study was intended to determine the effect of various doses of GTE (25, 50 and 100 mg/kg/day p.o. for 30 days) on doxorubicin-induced electrocardiographic and biochemical changes in rat heart. The latter included lactate dehydrogenase, creatine kinase, and glutamic oxaloacetate transaminase in serum and superoxide dismutase, catalase, and reduced glutathione, as well as membrane bound enzymes like $Na^+K^+ATPase,\;Ca^{2+}ATPase,\;Mg^{2+}ATPase$ and decreased lipid peroxidation in heart tissue Results demonstrated that rats which received GTE were less susceptible to such changes indicating protection afforded by GTE.

Functional Dyeing and Finishing Using Catechins Extracted from Green Tea (II) - Evaluation of Anti-oxidant Activity of the Fabrics treated with Green Tea Extracts -

  • Son, Son-Gi;Jang, Kyung-Jin;Kim, Tae-Kyeong;Jung, Jong-Suc;Choi, Young-Hee
    • Textile Coloration and Finishing
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    • v.20 no.5
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    • pp.7-13
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    • 2008
  • In order to introduce new functions onto textile fabrics, nylon and cotton were treated with green tea extracts. And then the anti-oxidant activity of fabrics treated with the extracts was evaluated by Blois method using DPPH ($\alpha$, $\alpha$-diphenyl- $\beta$-picrylhydrazyl). The anti-oxidant activity was exhibited on the textile fabrics treated as well as by the extracts itself. The cotton fabric treated with 10% o.w.f. of extract appeared to have almost 90% of anti-oxidant activity and 95% was obtained for nylon.

Effects of Green Tea Catechins (GTC) on the Treatment of Hangover and Prevention of Liver Disease

  • Lee, Mi-Yea;Kim, Won Shik;Lim, Yong
    • Korean Journal of Clinical Laboratory Science
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    • v.46 no.4
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    • pp.131-135
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    • 2014
  • Over-consumption of alcohol leads to many side-effects such as malnutrition, liver disease, and neuronal disorders and many investigators have tried to identify methods for preventing the side-effects of drinking. This study was carried out to investigate the effect of the beverage contained green tea catechins (GTC) on the alcohol administered rats. We observed that blood alcohol concentration level decreased significantly in plasma. GTC (200 mg/kg) also reduced the aspartate aminotransferase (AST) and alanine aminotransferase (ALT) level of the intoxicated rats. These results suggest that GTC may be useful for the prevention and therapy of hepatotoxic pathogenesis.

Improvement of analytical method for catechins in green tea (녹차의 카테킨류 분석법 개선)

  • Rah, Hyo-Hwan;Baik, Soon-Ok;Han, Sang-Bin;Bock, Jin-Young
    • Applied Biological Chemistry
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    • v.35 no.4
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    • pp.276-280
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    • 1992
  • Quantutative analysis of catechins by HPLC was studied. When the mobile phase was switched from the conventional(AOAC) Methanol, Acetonitril and Acetic acid solution in $H_2O$ to 0.06% Phosphate solution with Acetonitrile, N,N-Dimethyl formamide, and Ethyl acetate, retention time could be reduced from 45 min to 28 min, especially, we obtained sharper chromatogram of the compounds, either (-)EGCG or (-)ECG, which resulted in minimization of analytical erros. CVs of retention time $(0.32{\sim}3.97%)$ and peak area $(1.61{\sim}7.01%)$ indicated that the data were more reliable. Content of catechins in commerical teas analyzed by the method was $120.3{\sim}153.7\;mg/g$ in green teas which was about 4 times that in black tea.

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Changes of Some Chemical Compounds of Korean (Posong) Green Tea according to Harvest Periods (보성산 녹차의 채엽시기에 따른 화학 성분의 변화)

  • Kim, Sang-Hee;Han, Dae-Seok;Park, Jong-Dae
    • Korean Journal of Food Science and Technology
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    • v.36 no.4
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    • pp.542-546
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    • 2004
  • Changes in contents of catechins, caffeine, free amino acids, and minerals in green tea loaves according to harvest periods were compared. Total catechin content increased from 40.61 to 52.04 mg/g, while that of caffeine decreased from 17.56 to 14.61 mg/g according to harvest periods. Regardless of harvest periods, composition of catechins was epigallocatechin (EGC)>epigallocatechin gallate (EGCg)>epicatechin (EC)>gallocatechin (GC)>epicatechin gallate (ECg)>catechin (C)>gallocatechin gallate (GCg)>catechin gallate (Cg). Free amino acid content in green tea leaves was highest in young loaves, and gradually decreased according to harvest periods. Theanine content was markedly decreased with leaf aging, suggesting taste of green tea may be changed from mild to bitter with increasing harvest period. Analyses of mineral elements in green tea leaves showed that Fe, Mn, and Mg increased with leaf aging, while Cu showed opposite trend. Results reveal that content of some chemical compounds in Korean (Posong) green tea was highly dependent on harvest period.

Comparison of Antiplatelet Activities of Green Tea Catechins

  • Cho, Mi-Ra;Jin, Yong-Ri;Lee, Jung-Jin;Lim, Yong;Kim, Tack-Joong;Oh, Ki-Wan;Yoo, Hwan-Soo;Yun, Yeo-Pyo
    • Journal of Food Hygiene and Safety
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    • v.22 no.3
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    • pp.223-230
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    • 2007
  • We have previously reported that green tea catechins(GTC) displayed potent antithrombotic effect, which was due to the antiplatelet activity. In the present study, the antiplatelet activity of each green tea catechin components was compared in vitro. Galloylated catechins including (-)-epigallocatechin gallate (EGCG), (-)-gallocatechin gallate (GCG), (-)-epicatechin gallate (ECG) and (-)-catechin gallate (CG), significantly inhibited collagen $(5{\mu}g/mL)-induced$ rabbit platelet aggregation with $IC_{50}$ values of 79.8, 63.0, 168.2 and $67.3{\mu}M$, respectively. EGCC GCG and CG also significantly inhibited arachidonic acid (AA, $100{\mu}M$)-induced rabbit platelet aggregation with $IC_{50}$ values of 98.9, 200.0 and $174.3{\mu}M$, respectively. However catechins without gallate moiety showed little inhibitory effects against rabbit platelet aggregation induced by collagen or AA compared with galloylated catechins. These observations suggest that the presence of gallate moiety at C-3 position may be essential to the antiplatelet activity of catechins and the presence of B ring galloyl structure may also contribute to the antiplatelet activity of GTC. In line with the inhibition of collagen-induced platelet aggregation, EGCG caused concentration-dependent decreases of cytosolic calcium mobilization, AA liberation and serotonin secretion. In contrast, epigallocatechin (EGC), a structural analogue of EGCG lacking a galloyl group in the 3' position, although slightly inhibited collagen-stimulated cytosolic calcium mobilization, failed to affect other signal transductions as EGCG in activated platelets. Taken together, these observations suggest that the antiplatelet activity of EGCG may be due to inhibition of arachidonic acid liberation and inhibition of $Ca^{2+}$ mobilization and that the antiplatelet of EGCG is enhanced by the presence of a gallate moiety esterified at carbon 3 on the C ring.