• 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.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.91-92
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• 2001

Flavonols are polyphenolic compounds that are present in dietary plant-based foodstuffs and beverages (e. g. apple, onion, grape fruit, tea) and medicinal plants (e. g. Crategus, Ruta graveolens, Silybum marianum, Fagopyrum species) in high concentrations. They have been reported to exhibit a wide variety of biological effects, including anti-inflammatory, antiviral, antioxidant and free-radical-scavenging activities.(omitted)

• Journal of agriculture & life science
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• v.44 no.5
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• pp.91-99
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• 2010

The objective of this work was to investigate the influence of ultrasonification on extraction yield and chemical properties of green tea infusion. Changes in total soluble matter(TSM), vitamin C, total phenolic compounds, flavonols, catechins, caffeine, free amino acids contents in green tea infusion(GTI) influenced by ultrasonification at $60^{\circ}C$ of extraction temperature for 1, 5, 30, and 60 min were investigated. The amount of infused TSM increased about 5.3% by ultrasonification for 60min. Vitamin C contents also increased 0.21, 0.16, 0.31 mg/g from 1 to 30 min by ultrasonification. However, vitamin C decreased from 2.47 to 2.22 mg/g at 60min. Total phenol compounds contents increased about 10~13 mg/g on all extraction times by ultrasonification. Flavonols such as, myricetin, quercetin, kaempferol were increased to doubled contents as an influence of ultrasonification. Catechins such as, EGCG, EGC, ECG, EC, (+)-C and caffeine contents showed same tendency as the results of vitamin C. On the other hand, result of free amino acids showed different tendency. All amounts of free amino acids did not increase by ultrasonification. Consequently, content of bioactive compounds such as, vitamin C, total phenolic, flavonols and catechins in green tea infusion were influenced by ultrasonification.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.6
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• pp.2923-2933
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• 2016

Recently, we reported an inverse association between high 'mate' intake (infusion of Ilex paraguariensis herb, a staple beverage in temperate South America) and breast cancer (BC) risk. Stronger inverse associations were found in high strata of tea, vegetable, fruit and energy intakes, and in overweight/obese women, suggesting possible roles for 'mate' mainly from its antioxidant contribution. The present study attempted to thoroughly explore possible associations among 'mate' and tea intake, dietary antioxidants and BC risk. Combining two databases of previous studies, 572 BC incident cases and 889 controls were interviewed with a specific questionnaire featuring socio-demographic, reproductive and lifestyle variables, and a food frequency questionnaire (64 items), focusing on 'mate' intake (consumer status, daily intake, age at start, age at quit, duration of habit). Food-derived nutrients were calculated from available databases. Odds ratios (OR) and their 95% confidence intervals were calculated through unconditional logistic regression, adjusting for relevant potential confounders. The highest 'mate' intake was significantly inversely associated with BC risk for both low and high carotenoids (OR=0.40 vs. 0.41), vitamin C (OR=0.33 vs. 0.50), vitamin E (OR=0.37 vs. 0.45), flavonols (OR=0.38 vs. 0.48) and reduced glutathione (OR=0.48 vs. 0.46) strata. High tea intake showed significant inverse risk associations only with high carotenoids (OR=0.41), vitamin E (OR=0.48) and reduced glutathione (OR=0.43) strata. In conclusion, a strong and inverse association for 'mate' intake and BC was found, independent of dietary antioxidant levels. Also strong inverse associations with tea intake were more evident only at high levels of certain dietary antioxidants.

• Journal of Nutrition and Health
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• v.35 no.10
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• pp.1081-1088
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• 2002

Flavonoids are phytochemicals that occur ubiquitously in plant foods that have been reported to have potential roles in the prevention of cancer, inhibition of platelet aggregation or inflammation. However, there was no accurate data reported on the intake of middle-aged Korean population. The present study was designed to assess dietary intake of flavonoids (including isoflavones) of 304 adults (20-59 yr, male 115, famale 189) living in Daejeon area using semi-quantitative food frequency questionnaire. The questionnaire consisted of 50 food items, including vegetables, soy products, seaweeds, nuts and beans, fruits and beverages. Our self-administered questionnaire contained questions regarding subject's habitual diet and alcohol intake over the previous 3 months. Average daily intake of individual flavonols such as quercetin, kaempferol, myricetin, and flavones such as luteolin, apigenin was 15.7, 8.7, 0.21, 2.07, 0.03 mg/day, respectively. Daily intake of daidzein and genistein, which are the commonly found isoflavones in soy products, were 16.6 and 21.4 mg/day, respectively. Combined intake of flavonoids was 64.3 mg/day. No effect of smoking, drinking and exercise was observed on flavonoids consumption. Food items that has the highest daily intake of each compounds were; quercetin (onion, 9.49 mg/day), kaempferol (strawberry, 1.18 mg/day), myricetin (green tea, 0.81 mg/day), apigenin (lettuce, 0.03 mg/day), luteolin (onion, 0.05 mg/day), daidzein (soybean sprout, 5.99 mg/day), genistein (soybean sprout, 7.02 mg/day). These findings provide valuable information on understanding the dietary flavonoids intake from a typical Korean daily diet, which might help to identify the risks for developing various diseases.

• Journal of Life Science
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• v.27 no.4
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• pp.476-481
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• 2017

Polyphenols are secondary metabolites produced by higher plants and have been used as antiallergic, anticancer, antihypertensive, antiinflammatory, antimicrobial and antioxidant agents. They are generally divided into flavonoids and non-flavonoids. The antimicrobial activity of flavonoids are stronger than that of non-flavonoids. The skeleton structures of flavonoids possessing antimicrobial activity are chalcone, flavan-3-ol (catechin), flavanone, flavone, flavonol and proanthocyanidin. The flavonols are shown antibacterial activity against several gram-positive bacteria (Actinomyces naeslundii, Lactobacillus acidophilus and Staphylococcus aureus) and gram-negative bacteria (Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella melaninogenica and Prevotella oralis). Among of non-flavonoids, caffeic acids, ferulic acids and gallic acids showed antimicrobial activity against gram-positive (Listeria monocytogenes and S. aureus) and gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). These are found to be more efficient against the E. coli, L. monocytogenes, P. aeruginosa and S. aureus than antibiotics such as gentamicin and streptomycin. The kaempferol and quercetin showed synergistic effect with ciprofloxacin and rifampicin against S. aureus and methicillin resistant S. aureus (MRSA). Epigallocatechin gallate (EGCG) acts synergistically with various ${\beta}-lactam$ antibiotics against MRSA. In particular, the epicatechin, epigallocatechin (EGC), EGCG and gallocatechin gallate from Korean green tea has antibacterial activity against MRSA clinical isolates and the combination of tea polyphenols and oxacillin was synergistic for all the clinical MRSA isolates.