• Journal of the Korean Society of Food Culture
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• v.18 no.5
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• pp.443-456
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• 2003

The lyophilization of the solution extracted from 60 percent of acetone applied to persimmon leaves, the compounding process in accordance with the solution's concentration, and the gel filteration through Sephadex G-50 of biologically activated substances obstructing enzyme activity, such as tyrosinase, xanthine oxidase, and angiotesin converting enzyme (ACE) led to the assumption that polyphenol was the compound serving as biologically activated substances obstructing enzyme activity. Xanthine oxidase involved in pruine metabolism oxidizes hypoxanthine to xanthine and xanthine to uric acid. In the continuous study for natural compound, nine flavan-3-ols have been isolated from the persimmon leaves. The structures of (+)-catechin, (+)-gallocatechin, procyanidin B-1, pyrocyanidin C-1, prodelphinidin B-3, gallocatechin-$(4{\alpha}{\rightarrow}8)$-catechin, procyanidin B-7-3-O-gallate, procyanidin C-1-3'-3'-3'-O-trigallate and (-)-epigallocatechin-$(4{\alpha}{\rightarrow}8)$-epigallocatechin-$(4{\alpha}{\rightarrow}8)$-catechin were established by NMR and their inhibitory effect on xanthine oxidase activity was investigated. Procyanidin B-7-3-O-gallate, (-)-epigallocatechin-$(4{\alpha}{\rightarrow}8)$-epigallocatechin-$(4{\alpha}{\rightarrow}8)$-catechin and procyanidin C-1-3'-3'-3'-O-trigallate showed 94%, 90.69%, 80.90% inhibition at $100\;({\mu})M$ and inhibited on the angiotensin converting enzyme respectively. Procyanidin B-7-3-O-gallate and procyanidin C-1-3'-3'-3'-O-trigallate showed 66%, 63% inhibition at $100\;({\mu})M$ and inhibited on the xanthine oxidase competitively. Procyanidin C-1-3'-3'-3'-O-trigallate showed 70% inhibition at $100\;({\mu})M$ and inhibited on the tyrosinase competitively.

• Journal of Nutrition and Health
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• v.47 no.3
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• pp.176-185
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• 2014

Purpose: The purpose of this study was to investigate the relationship between dietary flavonoids intake and metabolic syndrome (MetS) in Korean women with polycystic ovary syndrome (PCOS). Methods: A total of 223 subjects (mean age; $27.3{\pm}4.2$ yrs, range; 17-38 yrs) were divided into the MetS group (n = 27) and non-MetS group (n = 196). Dietary intake data were assessed by 24-hour recall method for two non-consecutive days and the average of the two days was used to estimate the usual dietary intake. Dietary habits were assessed using the Mini Dietary Assessment (MDA) score. We analyzed the intakes of six flavonoid classes (anthocyanidins, flavan-3-ols, flavanones, flavones, flavonols, and iso-flavones) using a flavonoids database. Results: After adjustment for age, total energy intake, alcohol consumption, smoking, regular exercise, and oral contraceptive use, dietary flavonols intake was significantly lower in the MetS group ($5.1{\pm}2.4$ mg/d) than in the non-MetS group ($8.9{\pm}2.8$ mg/d) (p = 0.0472). Intakes of other flavonoids except for flavonols did not differ between the two groups. In MDA scores, significant differences were observed only for that related to daily consumption of fruit or fruit juice (p = 0.0180). A significant inverse relationship was observed between flavonols intake and the risk of MetS (4th vs. 1st quartile, OR = 0.11, 95% CI = 0.02-0.62, p for trend = 0.0131). Conclusion: These results suggest that higher intake of flavonols may be beneficial for MetS in PCOS women.

• Journal of Nutrition and Health
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• v.48 no.6
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• pp.496-506
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• 2015

Purpose: The purpose of this study was to estimate dietary flavonoids intake of Korean adolescents. Methods: Using data from the 2007-2012 Korean National Health and Nutrition Examination Survey, a total of 3,957 subjects aged 12-18 were included in this study. We estimated individual daily intake of total flavonoid and six flavonoid classes including flavonols, flavones, flavanones, flavan-3-ols, anthocyanidins, and isoflavones by linking food consumption data with the flavonoids in the commonly consumed food database. The distribution of sociodemographic, health-related, and dietary factors according to flavonoids intake was examined. Results: Average dietary flavonoids intake of the study subjects was 195.6 mg/d in girls, and 189.4 mg/d in boys. The highest flavonoids intake group consumed significantly more fiber, vitamin C, legumes, fruits, and vegetables (p < 0.01) and less fat, grains, meats and dairy foods than other lower consumption groups (p < 0.001). Dietary flavonoid intake showed negative correlation with waist circumference and systolic blood pressure (p < 0.05). Conclusion: This study provided basic data for estimation of flavonoids intake of Korean adolescents. Further research will be required for analysis of the association of flavonoids intake and health-related factors such as cardiovascular risk factors.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.224-232
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• 2008

The health benefits associated with tea consumption have resulted in the wide inclusion of green tea extracts in botanical dietary supplements, which are widely consumed as adjuvants for complementary and alternative medicines. Tea contains polyphenols such as catechins or flavan-3-ols including (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG), as well as the alkaloid, caffeine. The contents of catechins and caffeine in green tea are considered as a standard of quality evaluation of green tea. Therefor, the purpose of this study was to investigate the most suitable HPLC condition for simultaneous determination of catechins and caffeine in green tea extracts. The efficient HPLC analytical condition of catechins and caffeine contained green tea extracts was developed. The gradient elution employed a $250\;mm\;{\times}\;4.6\;mm$ i.d. YMC-pak ODS-AM 303 column. The gradient system was used two mobile phases. A gradient elution was performed with mobile phase A, consisting of 0.1% aqueous phosphoric acid, and mobile phase B, comprising 100% MeOH, and delivered at a flow rate of 1 mL/min as follows: $0{\sim}25\;min$, 80% A; $26{\sim}50\;min$, $80{\sim}70%$ A; 51 min, 80% A. $51{\sim}55\;min$, 80% A. The UV detection wavelength was set at 280 nm. The limit of detection (LOD) for catechins and caffeine standards were under 50 ng/mL.

• Journal of Nutrition and Health
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• v.50 no.4
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• pp.391-401
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• 2017

Purpose: The purpose of this study was to estimate the dietary flavonoid intakes of Korean adults according to socioeconomic status. Methods: Using data from the 2007~2012 Korea National Health and Nutrition Examination Survey, a total of 31,112 subjects aged over 19 years were included in this study. We estimated individuals' daily intakes of total flavonoids and seven flavonoid subclasses, including flavonols, flavones, flavanones, flavan-3-ols, anthocyanins, proanthocyanidin, and isoflavones,by linking food consumption data with the flavonoids database for commonly consumed Korean foods. We compared intakes of flavonoids according to the levels of household income and education. Results: Average dietary flavonoid intakes of the study subjects were 321.8 mg/d in men and 308.3 mg/d in women. Daily flavonoid intakes were positively associated with household income level (p < 0.0001) and education level (p < 0.0001). The subjects in the highest household income and highest education level group (OR 0.37, 95% CI 0.30~0.45, p < 0.0001 in men, OR 0.50, 95% CI 0.41~0.60, p < 0.0001 in women) had a lower likelihood of having low total flavonoid intake (less than 25 percentile) compared to the lowest household income and lowest education level group. The food group that contributed to total flavonoid intake with the biggest difference between the lowest and highest groups for both household income level and education level was beverages. Conclusion: This study shows that socioeconomic status was positively associated with flavonoid intake in a representative Korean population. Further research is needed to analyze the association of flavonoid intake with health outcomes according to socioeconomic status such as household income and education level.