• The Korean Journal of Food And Nutrition
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• v.27 no.6
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• pp.1051-1058
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• 2014

Yuza (Citrus junos) had 3 varieties and they had variable physiochemical properties. This study analyzed free sugar, hesperidine, naringin, flavonoid contents and antihypertensive activities according to variety and harvest time of Yuza. Three Yuza varieties, native (C. junos I), improved I (C. junos I + Poncirus trifoliata), improved II (C. junos I + C. junos II) were used. Harvest time could influence biochemical properties of Yuza such as acidity and $^{\circ}brix$. When the Yuza harvested at behind of season, the sugar/acid ratio went up because the acidity was decreased but sugar content was increased. Fructose content was dramatically high at November, Yuza of the season. Total flavonoids was high in pulp parts of improved II and in juice of native one harvested at October. The content of hesperidin and naringin in peels and juices were high in immature fruits fresh-picked at July since then they were decreased steadily and there were no difference according to varieties. The angiotensin converting enzyme (ACE) inhibition was powerful at pulp of Yuza in particular native one picked at November.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1819-1825
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• 2010

This study was carried out to investigate the quality characteristics of ginseng JungKwa produced with hot-water extract from Maegmundong (MGJ) instead of sugar. Chemical characteristics of MGJ and control ginseng JungKwa produced by sucrose (CGJ) were measured by proximate constituents, free sugars, ginsenosides, total phenolic compound, flavonoid content, and antioxidative activity was measured by electron donating abilities and hydrogen peroxide scavenging activity. Carbohydrate, crude protein, crude ash contents of MGJ were 76.40, 1.46 and 3.49%, where as those of CGJ were 80.01, 0.59 and 0.96%. Free sugar compositions of MGJ were fructose (32.42%), oligosaccharide (16.91%), disaccharide (13.91%) and glucose (13.16%). Eleven ginsenosides types were detected on MGJ and 9 kinds on CGJ; their contents were 740.1 and 675.6 mg%, respectively. Total phenolic compound and flavonoid content were 5.46 and 0.016% on MGJ, 5.02 and 0.014% on CGJ, respectively. In physiological characteristics, the $IC_{50}$ of electron donating ability by DPPH on MGJ was about 34.5 mg/mL and ability was slightly higher than CGJ, although there's not much difference in ability between MGJ and CGJ. Hydrogen peroxide scavenging activities were 92% on MGJ and 96% on CJG when treated at $50{\mu}g$/mL.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.9
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• pp.1357-1362
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• 2014

This study compared the antioxidant effects of two kinds of black raspberry extract, obtained from fruits of Rubus coreanus and Rubus occidentalis, which can be found in Korea. The fruits of R. coreanus and R. occidentalis were each extracted with 0%, 25%, 50%, 75%, and 100% ethanol (EtOH). Among the extracts of these two varieties, 50% EtOH extract of R. occidentalis showed the highest contents of total polyphenols ($46.96{\pm}2.78mg/g$) and flavonoid compounds ($11.77{\pm}0.81mg/g$). The 50% EtOH extract of R. occidentalis showed the highest antioxidant activity ($84.77{\pm}0.97%$) in terms of DPPH radical scavenging activity. On the contrary, 25% EtOH extract of R. occidentalis showed the best antioxidant activity ($29.65{\pm}2.41%$) in terms of ABTS radical scavenging activity. In the results of ferric reducing antioxidant power (FRAP) assay, 50% EtOH extract of R. occidentalis showed the highest antioxidant activity ($0.49{\pm}0.02%$). In the cytotoxicity test stimulated with $H_2O_2$, the extracts of 75% and 100% EtOH from R. occidentalis showed the highest cell viability ($93.54{\pm}3.37%$ and $97.19{\pm}0.74%$, respectively). According to our results, extracts of R. occidentalis showed higher antioxidant activities than extracts of R. coreanus. Especially, total polyphenol and flavonoid contents of R. occidentalis showed the highest significant correlation with FRAP by Pearson's correlation (P=0.005 and P=0.013, respectively).

• Journal of Life Science
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• v.30 no.5
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• pp.443-451
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• 2020

Recently, thrombotic diseases have become rapidly more prevalent due to Westernized lifestyles and high-fat diets. In this study, the anti-thrombosis activities of the aerial parts of Sageretia thea were evaluated using ethanol extracts of the leaf (ST-L), branch (ST-B), and fruit (ST-F), and their anti-coagulation, platelet aggregation inhibition, and hemolytic toxicity were assessed. In comparison to the ST-F extract, the ST-B exhibited 6.7 times more polyphenol content, and the ST-L had 2.7 times more total flavonoid content. The ST-L and ST-B extracts showed stronger inhibitions of thrombin, prothrombin, and blood coagulation factors than aspirin, berry extracts, or commercial oriental herbs. Furthermore, ST-L and ST-B showed superior platelet aggregation-inhibitory activities than aspirin. The ST-F extract demonstrated only minor anti-thrombosis effects, and none of the extracts showed hemolysis against red blood cells up to 1 mg/ml. Phenolic acid and flavonoid analysis of the ST-L and ST-B extracts showed abundant rutin, isoquercitrin, and astragalin as the major active compounds. Further research on the anti-thrombotic activity of isoquercitrin, a rare flavonoid from quercetin, is necessary. This is the first report of isoquercitrin in Sageretia thea, and our results suggest that ST-L and ST-B extracts could therefore developed as anti-thrombosis agents.

• Journal of Life Science
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• v.30 no.8
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• pp.688-694
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• 2020

In a previous study, the total phenolic content in ethanol extracts of medicinal plants that naturally grow on Jeju Island were analyzed with the extracts of Raphiolepsis indica leaf found to have the highest. The current study was carried out to evaluate the total flavonoid content, radical-scavenging activity, and the protective effect of R. indica extracts and solvent fractions on oxidative stress in HaCaT keratinocytes. More specifically, total flavonoid content and 2-azino-bis 3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical-scavenging activity were measured to assess anti-oxidative activity, and protective effects against hydrogen peroxide (H₂O₂) were determined by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide assay on the HaCaT cells. Of the various fractions analyzed, the ethyl acetate extract of R. indica showed the highest total flavonoid content (149.13 mg/g extracts) and the lowest remaining ABTS. In addition, the ethyl acetate fraction was significantly more resistant against H₂O₂ than the negative control. Our results therefore suggest that an ethyl acetate fraction of R. indica protects HaCaT cells against oxidative stress and could prove useful for developing functional cosmetic materials.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.208-213
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• 2012

This study was performed to compare antioxidant activities of 80% EtOH extracts from young and mature fruit of three pear cultivars ('Wonhwang', 'Whangkeumbae', and 'Chuwhangbae') classified by three parts (peel, core, and flesh) of mature fruit. The total phenolics compound and flavonoid contents of 80% EtOH extracts from young fruit were 1.5-2.5 times higher than the mature fruit with great cultivar difference. In particular, the contents of those compounds were highest in 'Chuwhangbae' pear. The total phenolics compound and flavonoid contents of 80% EtOH extracts from mature fruit were the most in the peel, core, and flesh respectively. DPPH radical scavenging and $ABTS^+$ radical scavenging of 80% EtOH extracts from the young fruit were higher than the mature fruit of 'Chuwhangbae' pear. DPPH radical scavenging and ABTS+ radical scavenging of 80% EtOH extracts from mature fruit were the highest in the peel, core, and flesh respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.8
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• pp.1249-1254
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• 2013

The effect of extraction methods, such as reflux extraction (RE), autoclave extraction (AE), low temperature high pressure extraction (LTPE) and ultrasonification extraction (USE) on antioxidant activity of various species of Artemisia (Artemisia capillaris T., Artemisia princeps P., Artemisia annua L.) was investigated. The extraction yield of RE and AE was higher than other methods tested for all Artemisia. The total polyphenol and flavonoid content of Artemisia sp. extracts from RE was highest of the extraction methods tested. The total polyphenol and flavonoid content of A. capillaris T. extracted by RE was 260.82 mg GAE/g and 11.52 mg RHE/g, respectively. The A. capillaris T. extract showed higher DPPH and ABTS radical scavenging activity than that of the other tested Artemisia sp. Nitrite scavenging activity and superoxide dismutase (SOD)-like activity of various extracts from RE was 45.48% and 68.29% (A. capillaris T.), 45.73% and 61.43% (A. princeps P.), and 44.25% and 58.19% (A. annua L.), respectively. The RE method was the most effective method for extracting antioxidant substances from various A. capillaris T. compared with AE, LTPE and USE. These results suggest that extracts of Artemisia sp. from RE can be used as bioactive and functional materials in the food industry.

• Journal of Life Science
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• v.26 no.12
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• pp.1415-1421
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• 2016

This study was worked to investigate the antioxidant activity and the blood circulation improvement effect of two Hibiscus syriacus extracts divided into fermented H. syriacus extract and non-fermented H. syriacus extract. As the results of in vitro experiment, both of fermented H. syriacus extract and non-fermented H. syriacus extract had the DPPH free radical scavenging effect and the high contents of polyphenol and flavonoid known as antioxidant components in dose-dependent manner. Six weeks female C57BL/6 mice were divide into four groups and fed high diets for 28 days. Also fermented H. syriacus extract and non-fermented H. syriacus extract was daily intraperitoneal administration for 28 days at 2 mg/kg of body weight of mice. In vivo C57BL/6 mice experiment of normal diet group (NOR), high-fat diet group (CON), high-fat diet plus fermented H. syriacus extract group (FHS) and high-fat diet plus non-fermented H. syriacus extract group (NFHS), each of total cholesterol, triglyceride and low density lipoprotein (LDL) was decreased in both of FHS and NFHS groups, meanwhile high density lipoprotein (HDL) was increased (p<0.01). Conclusion, the results confirmed that H. syriacus containing the high contents of the antioxidant activity components had the significant effects of blood circulation improvement.

• Food Science and Preservation
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• v.18 no.5
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• pp.764-772
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• 2011

Hot-water and 70%-ethanol Smilax china leaf extracts were prepared, and their total polyphenol and flavonoid contents, DPPH-radical-scavenging ability, nitrite-scavenging ability, and antimicrobial activity were determined. The total polyphenol contents of the hot-water and ethanol extract were $5.433{\pm}0.171$ and $13.060{\pm}0.110mg/g$, respectively; their flavonoid contents were $1.599{\pm}0.017$ and $3.005{\pm}0.084mg/g$; their DPPH-radical-scavenging abilities, assayed at 1.0 mg/mL, were 33.6 and 92.3%; and their nitrite-scavenging abilities, assayed at 0.1-2.0 mg/mL, were 37.9-61.6 and 38.4-77.8%. The 70%-ethanol extract showed higher antimicrobial activity than the hot-water extract. The antimicrobial activities were high in Bacillus cereus, Vibrio parahaemolyticus, Salmonella typhymurium, and Staphylococcus aureus, in that order. The antimicrobial substances in the two extracts were maintained after heating at $65-125^{\circ}C$ for 30 min.

• Korean Journal of Plant Resources
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• v.24 no.1
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• pp.23-29
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• 2011

In order to screen the functional constituents from nature resource, we studied the bioactivities of methanol extract of the Liriodendron tulipifera branch(MLT). The total phenolic and flavonoid contents, DPPH radical scavenging capacity, reducing power, $Fe^{2+}$ chelating ability, inhibition of lipid peroxidation and cell toxicity of MLT were investigated in this study. We found that the total phenolic and flavonoid content of MLT is 75.34 mg gallic acid/g and 20.15 mg quercetin/g respectively. MLT exhibited the antioxidant activity on DPPH radical with a $EC_{50}$ value of $289.68\;{\mu}g$/mL, the absorbance is 0.388 at $100\;{\mu}g$/mL in reducing power assay, MLT prevented 38.56% lipid peroxidation at $200\;{\mu}g$/mL. Furthermore, MLT exhibits the potent anti-proliferative activity which inhibited 56.94%, 35.73% growth of HT-29 and Hela cell at $200\;{\mu}g$/mL respectively. It showed that the antioxidant activities of MLT were correlated with its total phenolic and flavonoid contents. However further study need to be exploring in the future.