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.
Adolescent* ; Anthocyanins ; Ascorbic Acid ; Blood Pressure ; Edible Grain ; Fabaceae ; Female ; Flavanones ; Flavones ; Flavonoids* ; Flavonols ; Fruit ; Humans ; Isoflavones ; Korea* ; Meat ; Nutrition Surveys* ; Risk Factors ; Vegetables ; Waist Circumference

This study aims to evaluate the changes of flavonoid contents and antioxidants activity of Jeju native citrus fruits juice according to the harvest date. Flavonoids such as quercatagetin, narirutin, hesperidin and neohesperidin were contained most plentifully in the juice of Jigak (Citrus aur- antium) by 573.73 mg/100 mL, Sadoogam (C. pseudogulgul) by 393.99 mg /100 mL, Soyooja by 29.63 mg/100 mL and Jigak (C. aurantium) by 201.23 mg/100 mL in the late August, respectively. The highest contents of nob-iletin, sinensetin and tangeretin among polymethoxyflavones were found in the juice of Hongkyool (C. tachibana) by 7.39 mg/100 mL, 2.24 mg/100 mL, 0.63 mg/100 mL in the late August, respectively. 3,5,6,7,8,3',4'- Heptamet- hoxyflavone recorded the highest amount in Punkyool (C. tangerina) by 0.27 mg/100 mL in the late August, but the other polymethoxyflavones including 3',4',7,8-tetramethoxyflavone, 3',4'-dimethoxyflavone, 4'-methoxyflavone, 5,6,7,3',4',5'-hexamethoxyflavone, scutellarein tetramethylether were observed only trace amount in all the citrus fruits. Flavonoid contents in the citrus fruit juices were the highest during early maturation and decreased rapidly while ripening. Total polyphenol contents were the highest in the late August and decreased with ripening. However from the late December, the contents were increased again. Antioxidant activities of the fruits were evaluated as electron donating ability and were the lowest in the late September and increased with the fruit ripening. These results suggest that quercetagetin among all the flavonoids was most plentiful in Jigak and Dangyooja (C. grandis), so that the fruits could be used for industrial material of flavonoids and antioxidant agents.
Antioxidants ; Apigenin ; Chromones ; Citrus ; Disaccharides ; Electrons ; Flavanones ; Flavones ; Flavonoids ; Fruit ; Hesperidin

Myricetin and its glycosides are important flavonols commonly found in plants, and they are natural organic compounds with diverse pharmacological activities. Numerous studies have demonstrated that myricetin and its glycosides are strong antioxidants that have great potential in preventing, alleviating and assisting the treatment of chronic non-infectious diseases such as cancer, diabetes, and cardiovascular diseases. In addition, myricetin and its glycosides also have antiviral, antibacterial, anti-inflammatory, analgesic, liver protection and other pharmacological activities. Myricetin contains more hydroxyl groups in the parent ring structure than other flavonoids, so myricetin and its glycosides have stronger pharmacological activities than other flavonols or flavonoids such as quercetin and kaempferol. Therefore, myricetin and its glycosides have great development and application prospects. In this paper, the classification and distribution of myricetin and its glycosides, their pharmacological activity and mechanism, as well as comparison with other flavonoids were reviewed. In addition, limitations of the current research and application of myricetin and its glycosides were analyzed, and the further studies on pharmacological activities as well as their dose-activity relationship, structure-activity relationship, chemical modification, biosynthesis and application prospects of myricetin and its glycosides were discussed and proposed.
Flavonoids ; Flavonols ; Glycosides ; Quercetin

Flavonoids have been hypothesized to reduce the risk of chronic diseases, but the lack of a flavonoid database hampered epidemiological studies addressing this issue in Korea. In this study, we developed a flavonoid database, based on a systematic review. A total of 1549 food items containing flavonoids were selected using the Korean Nutrient Database. Among them, flavonoid contents for only 649 food items were evaluated with analytical values and the remaining 900 items were replaced with adaptations or calculations from similar items. The developed flavonoid database covered 93.2% of fruits and fruit juices, 76.1% of vegetables, 98.4% of legumes and legume products, and 85.0% of all plant foods overall (1,549 items) as reported by the 24-hr dietary recall method regarding the 2008 Korean National Health and Nutrition Examination Survey. We found that this flavonoid database, overall, included 95.6% of all mainly consumed plant foods by Koreans. This flavonoid database is expected to be useful in regards to the correlation study of flavonoid intake and chronic diseases.
Anthocyanins ; Chronic Disease ; Fabaceae ; Flavones ; Flavonoids ; Flavonols ; Fruit ; Isoflavones ; Korea ; Nutrition Surveys ; Plants ; Statistics as Topic ; Vegetables

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.
Adult* ; Anthocyanins ; Beverages ; Education ; Family Characteristics ; Female ; Flavanones ; Flavones ; Flavonoids ; Flavonols ; Humans ; Korea* ; Male ; Nutrition Surveys* ; Social Class*

PURPOSE: The aim of this study was to examine the association of food security with the total and individual flavonoid intakes among Korean adults. METHODS: Study subjects were 13,454 men and 19,563 women aged 19 years and older who participated in the 2007~2012 Korea National Health and Nutrition Examination Survey. Subjects were classified into food-secure and food-insecure groups using the answers to a self-reported question on food sufficiency of subjects' household. The total and individual flavonoid intakes were calculated by linking 24-h dietary recall data of subjects with a flavonoid database. Mean differences in dietary outcomes by food security status, and major food sources of total flavonoids were examined. RESULTS: In this cross-sectional study, 5.8% of male adults and 6.6% of female adults were in food insecure households. Mean daily intakes of total flavonoids, flavonols, flavones, flavanones, flavan-3-ols, isoflavones, and proanthocyanidins were significantly lower in food-insecure groups than food-secure groups among both male and female adults. The differences were maintained in total flavonoids, flavones, flavanones, and flavan-3-ols after adjusting for total energy intake. Mean intakes of fruits and vegetables were significantly lower in food-insecure groups and the total flavonoid intake from fruits and vegetables was also significantly lower in food-insecure groups. The major food sources of total flavonoids were apples (20.7%), mandarines (12.0%), and tofu (11.5%) in the food-secure group, and apples (14.9%), tofu (13.3%), and mandarines (12.6%) in the food-insecure group. CONCLUSION: This study showed that food insecurity was associated with lower intakes of flavonoids and reduced intakes of fruits and vegetables in a representative Korean population.
Adult* ; Cross-Sectional Studies ; Energy Intake ; Family Characteristics ; Female ; Flavanones ; Flavones ; Flavonoids ; Flavonols ; Food Supply* ; Fruit ; Humans ; Isoflavones ; Korea* ; Male ; Malus ; Nutrition Surveys* ; Proanthocyanidins ; Soy Foods ; Vegetables

Excessive accumulation of beta-amyloid peptide (Abeta) is one of the major mechanisms responsible for neuronal death in Alzheimer's disease. Flavonoids, primarily antioxidants, are a group of polyphenolic compounds synthesized in plant cells. The present study aimed to identify flavonoid compounds that could inhibit Abeta-induced neuronal death by examining the effects of various flavonoids on the neurotoxicity of Abeta fragment 25-35 (Abeta25-35) in mouse cortical cultures. Abeta25-35 induced concentration- and exposure-time-dependent neuronal death. Neuronal death induced by 20 microM Abeta25-35 was significantly inhibited by treatment with either Trolox or ascorbic acid. Among 10 flavonoid compounds tested [apigenin, baicalein, catechin, epicatechin, epigallocatechin gallate (EGCG), kaempferol, luteolin, myricetin, quercetin, and rutin], all except apigenin showed strong 1,1-diphenyl-2-pycrylhydrazyl (DPPH) scavenging activity under cell-free conditions. The flavonoid compounds except apigenin at a concentration of 30 microM also significantly inhibited neuronal death induced by 20 microM Abeta25-35 at the end of 24 hours of exposure. Epicatechin, EGCG, luteolin, and myricetin showed more potent and persistent neuroprotective action than did the other compounds. These results demonstrated that oxidative stress was involved in Abeta-induced neuronal death, and antioxidative flavonoid compounds, especially epicatechin, EGCG, luteolin, and myricetin, could inhibit neuronal death. These findings suggest that these four compounds may be developed as neuroprotective agents against Alzheimer's disease.
Alzheimer Disease ; Animals ; Antioxidants ; Apigenin ; Ascorbic Acid ; Catechin ; Flavonoids ; Luteolin ; Mice ; Neurons ; Neuroprotective Agents ; Oxidative Stress ; Plant Cells ; Quercetin

The chemical constituents of 95% ethanol extract of Melastoma dodecandrum were isolated and purified by chromatography on silica gel, Sephadex LH-20, and HPLC, to obtain thirteen compounds eventually. On the basis of their physico-chemical properties and spectroscopic data, these compounds were identified as quercetin (1), quercetin-3-O-&beta;-D-glucopyranoside (2), quercetin-3-O-(6"-O-p-coumaroyl) -&beta;-D-glucopyranoside (3), kaempferol (4), kaempferol-3-O-&beta;-D-glucopyranoside (5), kaempferol-3-O- [2",6"-di-O-(E)-coumaroyl]-&beta;-D-glucopyra-noside (6), luteolin (7), luteolin-7-O-(6"-p-coumaroyl) -&beta;-D-glucopyranoside (8), apigenin (9), apigenin-7-(6"-acetyl-glucopyranoside) (10) , naringenin (11), isovitexin (12), and epicatechin-[8,7-e] -4&beta;-(4-hydroxyphenyl)-3,4-dyhydroxyl-2(3H)-pyranone (13). Eight compounds(3,5,6,8-11 and 13) were obtained from M. dodecandrum for the first time.
Apigenin ; analysis ; Chromatography ; methods ; Chromatography, High Pressure Liquid ; Dextrans ; Flavanones ; analysis ; Flavonoids ; analysis ; chemistry ; Glycosides ; analysis ; chemistry ; Kaempferols ; analysis ; Luteolin ; analysis ; Magnoliopsida ; chemistry ; Plants, Medicinal ; chemistry ; Quercetin ; analysis ; Silica Gel

The flavonoids in Panax notoginseng were qualitatively analyzed by ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry(UPLC-Q-TOF-MS), and the content of three main flavonoids in P. notoginseng of different specifications and grades collected from different habitats was determined by HPLC-DAD. Flavonoids and anthocyanins were analyzed by UPLC-Q-TOF-MS/MS in the positive and negative ion modes, respectively. Twelve flavonoid glycosides and one anthocyanin glycoside in P. notoginseng were identified, but no flavonoid aglycones were detected. Among them, 12 compounds were identified in the underground part of P. notoginseng for the first time and eight compounds were first reported in this plant. Moreover, six and four compounds were identified in the Panax genus and the Araliaceae family for the first time, respectively. A method for simultaneous determination of three flavonoids in P. notoginseng was established by HPLC-DAD. The content of flavonoids in 721 P. notoginseng samples of 124 specifications and grades collected from 20 different habitats was simultaneously determined. Among three flavonoids determined, the content of quercetin-3-O-(2″-β-D-xylosyl)-β-D-galactoside was the highest with the average content in the tested samples of 161.0 μg·g~(-1). The content of compounds quercetin-3-O-hexosyl-hexoside and kaempferol-3-O-pentosyl-hexoside was relatively low, with the average content of 18.5 μg·g~(-1)(calculated as quercetin-3-O-sophoroside) and 49.4 μg·g~(-1)(calculated as kaempferol-3-O-sangbu diglycoside). There were significant differences in flavonoids content of samples from different production area. The content of flavonoids in spring P. notoginseng was significantly lower than that in winter P. notoginseng when the other influencing factors such as production areas, germplasm resources, and cultivation conditions were fixed. As for P. notoginseng of different specifications, the flavonoid content in the part connecting the taproot and the aboveground stem was significantly higher than that in other parts. The results of large-scale data showed that the flavonoid content gradually increased with the increase in the number of heads. There were significant differences between the flavonoid content in most specifications and grades, especially the 20-head P. notoginseng and countless head P. notoginseng, whose content was significantly lower and significantly higher than that of other specifications and grades, respectively. This study provides a scientific basis for the study of the effective components and quality control of P. notoginseng from the perspective of flavonoids.
Flavonoids/analysis* ; Anthocyanins/analysis* ; Quercetin ; Chromatography, High Pressure Liquid/methods* ; Kaempferols ; Tandem Mass Spectrometry/methods* ; Glycosides

The present study was attempted to investigate and compare the antioxidant potency of several well-know flavonoids, antioxidant vitamin and commercially available popular beverages. The antioxidant potency was assessed by the effect on reducing oxidative DNA damage of human lymphocytes. Cellular oxidative DNA damage was measured by SCGE (single-cell gel electrophoresis), also known as comet assay. Lymphocytes were pre-treated for 30 minutes with wide ranges of doses of apigenin, kaempferol, luteolin, myricetin, rutin, quercetin, alpha-tocopherol (10,25,50,100,200,500,1000 micrometer) ,green tea extract or grape juice (10,50,100,250,500,1000 microgram/mL) followed by a H2O2(100 micrometer) treatment for 5 min as an oxidative stimulus. The physiological function of each antioxidant substance on oxidative DNA damage was analyzed as tail moment (tail length X percentage migrated DNA in tail) and expressed as relative DNA damage score after adjusting by the level of control treatment. Cells treated with H2O2 alone (positive control) had an extensive DNA damage compared with cells treated with phosphate buffered saline (PBS, negative control) or pre-treated with all the tested samples. Of all the six flavonoids, quercetin was the most potent antioxidant showing the lowest ED50 of 8.5 microgram/mL (concentration to produce 50% protection of relative DNA damage). The antoxidant potency of individual flavonoids were ranked as follows in a decreasing order; luteolin (18.4 microgram/mL), myricetin (19.0 microgram/mL) , rutin (22.2 microgram/mL) , apigenin (24,3 microgram/mL) , kaempferol (25.5 microgram/mL). The protective effect of alpha-tocopherol was substantially lower (highest ED50 value of 55.0 microgram/mL) than all the other flavonoids, while the protective effect was highest in green tea and grape juice with low ED5O value of 7.6 and 5.3, respectively. These results suggest that flavonoids, especially quercetin, and natural compounds from food product, green tea and grape juice, produced powerful anti-oxidative activities, even stronger than alpha-tocopherol. Taken together, supplementation of antioxidants to lymphocytes followed by oxidative stimulus inhibited damage to cellular DNA, supporting a protective effect against oxidative damage induced by reactive oxygen species.
alpha-Tocopherol ; Antioxidants ; Apigenin ; Beverages ; Comet Assay* ; DNA Damage* ; DNA* ; Flavonoids* ; Humans ; Luteolin ; Lymphocytes* ; Quercetin ; Reactive Oxygen Species ; Rutin ; Tea ; Vitamins ; Vitis