• Journal of the Korean Society of Food Culture
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• v.18 no.4
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• pp.303-310
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• 2003

This study was conducted to investigate immunofunctional activity of the polyphenol fractions isolated from Korean pear. In the experimental of Rosette forming cell, the results showed that all the polyphenol fractions enhance the cell count compared with the control group. Especially polyphenol fraction II and III showed highly significant effect on Rosette forming cell, and allergy inhibition. After antigen challenge, histamine content of blood of the polyphenol groups was lowered to near the normal group.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.299-304
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• 2004

This study was conducted to investigate the effects of the polyphenol fraction isolated from pear on the reduction of fat accumulation in rats fed on high fat diet for 5 weeks, which was examined by analyzing the lipid composition in serum, liver and feces biochemically. It was shown that the levels of total lipid and total cholesterol in serum were remarkably reduced in polyphenol fraction supplemented group as compared with the control group. The levels of total lipid and triglyceride were also significantly lower in polyphenol group than control group. The contents of total lipid, total cholesterol and triglyceride in feces were tended to be slightly increased in polyphenol group compared to control group. The total protein and albumin of polyphenol groups were lower compared to those of control group, which were not significant.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.115-120
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• 2003

Changes in polyphenol, free sugar, and organic acid concentrations and their antioxidative activities in Korean pear during storage were investigated. The antioxidant activity of polyphenols was evaluated. Polyphenol concentration in different parts of pear, peel, pulp and core, reached 25.7%. pH decreased while concentrations of free sugars, including fructose, glucose, and sucrose, increased during storage. Four organic acids, citric malic, succinic, and fumaric acids, were determined. Succinic acid was the major organic acid in the pulp and decreased after 5 month of storage. The antioxidative of polyphenol fractions I, II, and III on cottonseed, linseed, and fish oils were higher than those of the control group.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.111-115
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• 2000

This study was to investigate antiallergic contact hypersensitivity of the polyphenol fractons isolated from persimmon leaves (Diospyros kaki folum). The result of the allergic contact dermatitis is a common skin disease resulting from specific immunologic sensitization due to topically applied allergens. Here the contact hypersensitivity was assayed and obdominal skin morphological changes including mast cells were examined. At contact hypersensitivity assay, less right ear swelling occured in the polyphenol fraction I, II and III groups compared to the control group. The number of mast cells was significantly decreased in the sample groups than the control group.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.959-967
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• 2003

The polyphenol compounds of Korean pears were extracted with 60% acetone for 4 days at room temperature and purified using Sephadex LH-20 column chromatography, MCI gel column chromatography, Bondapak $C_{18}$ column chromatography, TLC, and HPLC. As a result, three compounds were isolated. The chemical structures of each compound were determined and identified using NMR, FAM-mass, and FT-IR. The compounds were confirmed as (+)-catechin (compound A), (+)-gallocatechin (compound B), (-)-epigallocatechin (compound C), and procyanidin B-3-3-o-gallate (compound D).

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.9
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• pp.1385-1390
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• 2016

Gallic acid is a representative hydroxybenzoic acid and is found in free form in several plants and in various esterified forms as a part of hydolyzable tannins. Convenient enzymatic transformation of trihydroxylated gallic acid with polyphenol oxidase originating from pear was evaluated to investigate whether polyphenol oxidase can be used as a valuable compound to improve the biological activity of gallic acid. Enzymatic oxidation processing of gallic acid using polyphenol oxidase was carried out for five different reaction times. The antioxidant effects of transformed gallic acid for different reaction times were evaluated via radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals. In addition, the anti-diabetic property of the transformed gallic acid was measured based on ${\alpha}$-glucosidase. Gallic acid reacted for 5 h showed significantly higher antioxidant and ${\alpha}$-glucosidase inhibitory activities compared to the tested positive control substances. Biotransformation of simple gallic acid induced by polyphenol oxidase might be responsible for enhancing the biological activity of gallic acid.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.116-119
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• 2000

This study was conducted to investigate antiallergy of the polyphenol fractions isolated from persimmon leaves (Diospyros kaki folum). The result of the passive cutaneous anaphylaxis (PCA) reaction of expriment on anti-allergy, the allergy remarkably decreased in polyphenol fraction I, II and III groups in comparison with the control group. After antigen challenge, histamine content of blood of the polyphenol groups was lowered to near the normal group.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.5
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• pp.769-775
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• 2010

The genus Lespedeza belonging to Leguminosae is an annual or perennial herb, which has been used as a Chinese herbal medicine. Antioxidant activity on DPPH ((1,1)-diphenyl-2-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylenebenzothiazoline-6-sulfonic acid) radicals and the contents of total polyphenol and flavonoid were analyzed with 12 methanol extracts from six Lespedeza genus plants with different plant parts. The highest content of total polyphenol was detected in the leaves of Lespedeza$\times$robusta (194.6 mg GAE/g), while the highest content of total flavonoid existed in the aerial part of Lespedeza thunbergii var. intermedia (47.9 mg QE/g). Generally, the amounts of polyphenol and flavonoid compounds were higher in the leaves than in the stems. The $SC_{50}$ value of DPPH radical scavenging activity ranged from 10.16 to 90.94 ppm, of which the strongest activity was determined in the leaves of L. robusta. Most ABTS radical scavenging activities from the investigated methanol extracts were higher than that of L-ascorbic acid, implying the excellent antioxidant activity. The radical scavenging activity in this study showed high correlation with the amount of total polyphenol rather than that of total flavonoid. These data suggest that the methanol extracts from these Lespedeza spp. could be potential candidates for natural antioxidants.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.493-497
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• 2002

The polyphenol compounds of Korea ginseng radix were extracted with 60% acetone for 4 days at room temperature and purified using Sephadex LH-20 column chromatography, MCI gel column chromatography, Bondapak $C_{18}$, column chromatography, TLC and HPLC. As a result in three compounds were isolated from Korean ginseng. In the inhibitory activities of angiotensin converting enzyme, compound Ⅱ showed the highest value of 31.86% inhibition at 157 ppm. Compound I showed 19.4% inhibition at 157 ppm. In the inhibitory activities of xanthine oxidase, compound I, II showed complete inhibition at 666 ppm but compound III didn't have inhibitory activity. In the inhibitory activities of tyrosninase, compound III showed 6.1% inhibition at 300 ppm and 28.6% at 400 ppm.

• Applied Biological Chemistry
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• v.45 no.4
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• pp.212-217
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• 2002

We purified polyphenols from persimmon leaf and tested their biological activity. The 60% acetone extract was lyophilized and applied to test enzyme inhibition of glucosyltransferase and tyrosinase. GTase was 82.4% inhibited at $1.8{\times}10^{-1}$ mg/ml and tyrosinase 21.7% inhibited at 0.8 mg/ml. The acetone extract was fractionated into F-1, 2, 3, 4, 5 by Sephadex Q-50 gel filtration and the fraction-1 and 2 showed higher enzyme inhibition activity than the other fractions. To the Proteinase K treatment and autoclaving of the two fractions had no effect on the enzyme activity, but these results suggested that active fraction was not protein but phenol ring completed compounds. By Sephadex LH-20, MCI-gel and Bondapak $C_{18}$ column chromatographies, compouds 1, 2, 3 and 4 from F-1 fraction, compounds 5 and 6 from F-2 fraction and compounds 7 , 8 from F-3 fraction were purified and re-crystallized. The purified compounds was assumed to be condensed tannins of frame flavan-3-ol frame on the basis of color reagent reaction and to be a mixture of monomer, dimer and trimer according to TLC analysis.