• Applied Biological Chemistry
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• v.40 no.3
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• pp.254-258
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• 1997

To examine the characteristics of the antioxidative property of Buckwheat components, acetone extracts from a buckwheat, Suwon 5, was fractionated using five solvents. Hexane, ethylacetate, ether, butanol and water fractions were obtained. Butanol fraction showed the greatest electron donating ability and inhibitory effect on lipid peroxidation. It also showed the most excellent activity in the superoxide radical scavenging activity by xanthine/xanthine oxidase-cytochrome c reduction system. Spectrophotogram of butanol fraction was similar to that of rutin. Superoxide radical scavenging activity was related to the contents of rutin. Inhibitory effect of each fraction on xanthine oxidase was also measured. Butanol fraction had the strongest inhibitory effect on xanthine oxidase and $IC_{50}\;was\;3.1\;{\mu}g$. The inhibition type of butanol fraction on xanthine oxidase turned out to be a mixture of the uncompetitive and non-competitive modes.

• Applied Biological Chemistry
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• v.44 no.4
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• pp.235-239
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• 2001

Effect of microwave treatment to barley bran was tested on antioxidative ability. Treatments of microwave at 100 W and 200 W, changed color of barley bran to brown, but carbonation was happening at 440 W. The electron donating abilities of barley bran was not reduced when treated with 100 W and 200 W microwave treatment for 10 minute. According to TBARS, the barley bran extract treated with 100 W and 200 W intensity of microwave for 10 min maintained the inhibition of lipid peroxidation, while the extract from 440 W microwave treatment for 5 min did not. Total phenolic contents were reduced with increased intensity of microwave treatment. The antioxidant activity of barley bran was not affected by microwave treatment at 100 W and 200 W, while the 440w microwave treatment reduced the activity due to carbonation of barley bran and decreased phenolic compounds.

• Applied Biological Chemistry
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• v.43 no.2
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• pp.148-152
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• 2000

The antioxidative activities of water-soluble extracts from leaves and stem bark of Morus alba and Cudrania tricuspidata were compared in vitro experimental models. Antioxidative activities were measured by inhibition activity against lipid peroxidation of mouse liver microsome, and they were showed in the following order; stem bark of C. tricuspidata(53%)>stem bark of M. alba(43%)>leaves of C. tricuspidata(38%)>leaves of M. alba(43%). In antioxidative activities determined by thiocyanate method and TBA method, the water-soluble extract of stem bark of C. tricuspidata showed the highest antioxidative activity. The water-soluble extracts of leaves were slightly stronger than other extracts in DPPH$({\alpha},{\alpha}'-diphenyl-{\beta}-picrylhydrazyl)$ method. The concentrations of total polyphenolic compound from water-soluble extracts of leaves and stem bark of M. alba and C. tricuspidata were 1.32%, 1.28%, 1.34% and 1.30% respectively. In these results, the water-soluble extract of stem bark from Cudrania tricuspidata showed the highest antioxidative activity.

• Applied Biological Chemistry
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• v.32 no.1
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• pp.23-29
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• 1989

Biochemical consequence of the accumulation in cells of superoxide $(O^{-}_{2})$ which was proposed to be probably a common chemical factor in the secondary process of the mechanism of chilling injury as well as in the visible light photodamage in cells of higher plants, has been investigated in the present work. Especially focused was the destructive effect of $O^{-}_{2}$ on the biochemical activity of mitochondria, as informations which support the suggestion that mitochondrial inner membrane is the major site of $O^{-}_{2}$ production have been collected. Mitochondria and submitochondrial particles (SMP) were prepared from soybean hypocotyls for this case study. When SMP were treated with the electrolytically produced $O^{-}_{2}$ they suffered not only inhibition of the membrane-bound enzymes as demonstrated by cytochrome c oxidase, but also lipid peroxidation of membrane as proved by malondialdehyde production. Malate dehydrogenase present in the protein extract from mitochondrial matrix was also inhibited by the $O^{-}_{2}$ treatment. These results exhibited the chaotic effect of the overproduction and accumulation of $O^{-}_{2}$ in cells under a certain abnormal circumstance such as environmental stress on the physiological function of mitochondrial; disruption of the cellular metabolic pathways and the structural integrity of membrane.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.1
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• pp.38-46
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• 2010

C3GHi, a novel black rice variety developed by conventional breeding has more high contents of cyanidine-3-glucoside (C3G) and a more strong antioxidant than normal black rice. In this study, we investigate the antioxidative potential and anti-diabetic activity of C3GHi and extract of it for the purpose of development of functional materials or replacement meal for diabetic patients. Using in vitro antioxidative activity assay system such as DPPH radical quenching assay, superoxide anion radical scavenging assay, inhibition of lipid peroxidation and DNA breakage assay, C3GHi extract was observed to have more high antioxidative activity than normal black rice breed. The glycemic index of a freeze dried powder of C3GHi brown rice showed $43.7\pm18.8$, which belonged to low GI food (GI of 55 or less). Using in vivo diabetic model such as db/db mice model and streptozotocininduced diabetic model, C3GHi rice extract decrease blood glucose level and inhibit oxidative stress in blood. From the results, we think that the C3GHi varieties have a potential for the functional materials or ingredient of meal replacement for diabetic patients.

• Journal of Life Science
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• v.30 no.7
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• pp.581-591
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• 2020

This study investigated the probiotic properties and physiological activities of Korean fermented foods such as sikhae, young radish kimchi, and bean-curd dregs. Among the isolated lactic acid bacteria, Pediococcus inopinatus BZ4, Lactobacillus plantarum SH1, Lactobacillus brevis SH14, Pediococcus pentosaceus YMT1, and Leuconostoc mesenteroides YMT6 demonstrated a greater than 60% survival rate at pH 2.5, along with an excellent survival rate even at 0.3% bile acid. These five bacteria showed strong flocculation ability in autoaggregation and coaggregation tests, indirectly clustering useful micro-organisms and inhibiting the attachment of pathogenic bacteria. In a cell surface hydrophobicity test, these bacteria showed adhesion to three solvents (ethyl acetate, chloroform, and xylene) and high hydrophobicity, thereby indicating excellent indirect cell adhesion to intestinal cells. The cell-free supernatants and intracellular extracts of the five lactic acid bacteria showed antioxidative activity in the form of 2,2-Diphenyl-1-picrylhydrazyl and 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging ability and lipid peroxidation inhibition. Antimicrobial activities were also observed in four pathogenic bacteria, namely E. coli KCTC 2571, H. pylori HPKCTC B0150, L. monocytogenes KCTC 13064, and S. aureus KCTC 1916. These results demonstrate that these five lactic acid bacteria could be used as probiotics with antioxidant and antimicrobial properties.

• Journal of Life Science
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• v.20 no.3
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• pp.326-335
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• 2010

The concentration of phenolics in Phellinus pini (CY001) extracts, expressed as mg of GAEs per g of P. pini fractions, and the EtOAc fraction (436.5 mg GAEs/g) of P. pini had a higher phenolic content than other fractions. Several biochemical assays were used to screen antioxidant properties such as reducing power, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, NBT/XO superoxide system and inhibition of DCF/AAPH peroxyl radicals. Among the six mushroom extracts, the EtOAc fraction from P. pini (CY001) showed the most potent DPPH radical, superoxide radical, and peroxyl radical scavenging activities, with $IC_{50}$ values of $11.49\;{\mu}g/ml$, $8.32\;{\mu}g/ml$, and $1.91\;{\mu}g/ml$, respectively. The EtOAc fraction of P. pini (CY001) significantly inhibited enzymatic lipid peroxidation and effectively attenuated LPS-induced NO production of RAW 264.7 cells without cytotoxicity. We also found that the EtOAc fraction had a significant hepato-protectant effect on tacrine-induced cytotoxicity in HepG2 cells. These findings suggest that P. pini (CY001) may have potential as a natural antioxidant, which contains compound(s) with radical scavenging activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.131-136
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• 2003

This research was aimed to evaluate the inhibition of oxidative changes of almond crackers by natural antioxidants (tocopherol, rosemary, and tea polyphenol). Almond crackers stored at $25^{\circ}C$ and 35$^{\circ}C$ for 70 days were evaluated with peroxide value, sensory and kinetic parameters. Results revealed that the antioxidative activity of rosemary was highy effective in inhibiting lipid oxidation at $25^{\circ}C$ and tea Polyphenol highly effective at 35$^{\circ}C$. Sensory evaluation indicated that the properties of odor and taste of almond crackers tended to positive effect with the addition of rosemary and tea polyphenol. Kinetic study in lipid oxidation showed the first order reaction at $25^{\circ}C$ and the zero order reaction at 35$^{\circ}C$. It was found that the kinetic parameter of oxidation reaction predicted for the shelf-life of almond cracker.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.3
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• pp.414-420
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• 2010

To develop tofu enhanced nutrition, storage stability and bioactivity, the soft tofu supplemented with red ginseng extract was prepared. Then, quality characteristics including storage stability, physical and chemical property, antioxidative activity, and sensory evaluation were measured. The pH and acidity of control tofu without red ginseng extract were not different from those of tofu supplemented with red ginseng extract during storage. The aerobic bacteria in the control tofu were detected from 10 days of storage whereas the number of total aerobic bacteria was reduced or not detected in the tofu added red ginseng extract during storage. The lightness and redness of the tofu supplemented with red ginseng extract were lower than those of control, but yellowness was higher. The addition of red ginseng extract did not also affect the texture of tofu, and increased lipid peroxidation inhibition and DPPH radical scavenging activity. Although the soft tofu manufactured with red ginseng extract showed a lower sensory preference in supplementation over 0.20% due to color, there was not much difference found until 0.18% red ginseng extract addition.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.162-166
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• 2005

Two flavonoids, 7-O-methyl-3',4'-didehydroxy quercetin (MDQ) and quercetin, isolated from Chinese propolis, which is the generic name for the resinous substance collected by honeybees from various plant sources, were tested for their antioxidant activity and protective effect against radiation-induced DNA damage in mouse lymphocytes. In antioxidant test, both compounds provided a dose-dependent scavenging effect on DPPH radical and a dose-dependent inhibitory effect on lipid peroxidation in mouse liver. Quercetin showed stronger scavenging and inhibitory effect than MDQ, and it also provided strong inhibition on superoxide anion radical generated in xanthine-xanthine oxidase system, but there was no inhibitory ability for MDQ. In comet assay using single cell gel electrophoresis, MDQ and quercetin showed a protective effect against DNA damage caused by gamma irradiation. They reduced DNA damage to 54% (p<0.01) and 53% (p<0.01) at 25 $\mu$mol, respectively. These results suggest that free radical scavenging seems to be associated with their catechol form on the B ring, and radioprotection appears to be a likely mechanism of antioxidant activity by these flavonoids.