• The Korean Journal of Food And Nutrition
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• v.24 no.1
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• pp.94-100
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• 2011

This study identified the formula of the antioxidant substance separated from the ethyl acetate and the butanol extract and tested the antioxidant properties with the electron donating ability(EDA). Each phase with the fractionated methanol extract from mulberry leaf was screened in advance for the antioxidant substance with EDA. As the result, activity appeared in the ethyl acetate and butanol phase and the antioxidant component was separated. As the consequence, 2 components from the ethyl acetate phase and 1 from the butanol phase were separated, among which the structures of the components from ethyl acetate were determined by wogonin and linarin, whereas the structure of the component from the butanol phase was determined by pectolinarin. In the screening of antioxidant activity by the scavenging effect of the DPPH radical, the wogonin and linarin components from ethyl acetate phase showed more powerful antioxidant property than the component from butanol. The results from this study indicate that the chemical compound separated from the ethyl acetate extract has more powerful antioxidant property than the one separated from the butanol extract. The components separated from the ethyl acetate extract were wogonin and linarin, which are flavonoids, whereas the component from butanol was pectolinarin. Therefore, this study suggested that the feasibility of mulberry leaf as a functional food additive and its value as a natural antioxidant is very high.

• Korean Journal of Pharmacognosy
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• v.42 no.1
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• pp.89-97
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• 2011

This study was conducted to investigate tyrosinase inhibitory effect, hyaluronidase inhibitory effect and antioxidant activity by DPPH radical scavenging method on the MeOH extract of 50 species medicinal plant for screening of functional properties. As a result, Chaenomeles sinensis Koehne extract among 50 species medicinal plant turned out to be having tyrosinase, hyaluronidase inhibitory effect and antioxidant activity. The major component of tyrosinase and hyaluronidase inhibitory effect was isolated from EtOAc extract of Chaenomeles sinensis Koehne. And the component of antioxidant activity was isolated from n-BuOH extract of Chaenomeles sinensis Koehne. Their structure of compounds were identified as oleanolic acid and (-)-epicatechin by spectroscopic evidence, respectively.

• Proceedings of the Ginseng society Conference
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• 1990.06a
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• pp.45-48
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• 1990

Maltol(2-methyl-3-hydroxy-r-pyrone), a component known to be present in Korean Ginseng root showed an antioxidant action but its potency as an antioxidant was low; about 1150th that of other antioxidants such as p-phenylenediamine , BHA and BHT. However, maltol was able to protect the oxidation adamants in biological systems such as adriamycin-induced membrane damage in isolated cardiomyocytes, parquet-induced toxicities in isolated hepatocytes and repercussion injury in isolated hearts. The antioxidant action of maltol was also shown to be effective in vivo. The antioxidant action of this compound was probably due to the removal of hydroxyl radicals. In view of the roles of oxygen radical in various pathological processes, Korean Ginseng root, which contains several antioxidants including maltol, is expected to have beneficial efforts on the oxygen radical-involved processes. Keywords Maltol, Oxygen free radicals, Lipid preoccupation, Repercussion injury and Korean ginseng

• Journal of Ginseng Research
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• v.14 no.2
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• pp.187-190
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• 1990

Maltol(2-methyl-3-hydroxy-r-pyrone), a component known to be present in Korean Ginseng root showed an antioxidant action but its potency as an antioxidant was low: about 1150th that of other antioxidants such as pphenylenediamine, BHA and BHT. However, maltol was able to protect the oxidation damages in biological systems such as adriamycin-induced membrane damage in isolated cardiomyocytes, paraquat-induced toxicities in isolated hepatocytes and reperfusion injury in isolated hearts. The antioxidant action of maltol was also shown to be effective in vivo. The antioxidant action of this compound was probably due to the removal of hydroxyl radicals. In view of the roles of oxygen radical in various pathological proceises, Korean Ginseng root which contains several antioxidants including maltol is expected to have beneficial effects on the oxygen radical-involved processes.

• Food Science and Biotechnology
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• v.15 no.2
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• pp.220-226
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• 2006

Component having antioxidant activity on lard during heating was separated from hexane extract of spinach, and its characteristic chemical structure was speculated through nuclear magnetic resonance spectroscopy, liquid chromatography-mass spectrometry, and Fourier transform infrared spectrophotometry. Lard was heated with hexane-, ethyl ether-, ethyl acetate-, or ethanol extract of spinach at $180^{\circ}C$ for 20 hr. Hexane extract of spinach, having highest antioxidant activity on lard during heating, was fractionated by silicic acid column chromatography (SACC), and SACC fractions having higher antioxidant activity on lard during heating were further separated by thin layer chromatography (TLC). Isolated compound from SACC fractions of hexane extract of spinach by TLC had sugar moieties and benzene ring along with hydroxy, carbonyl, and alkyl groups in the structure.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.5
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• pp.501-507
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• 2004

Some selected fruit juices and fermented red grape juices were investigated to determine the phenolic components by the Folin-Ciocalteu method and antioxidant capacity using α, α-diphenyl-β-picrylhydrazyl(DPPH) method. Commercial red grape beverages and red wines were also analyzed as control groups. In the juice, kiwi fruit had the highest phenolic components followed by orange(summer), red grape(Cambell Early:Yonng-Chun), mandarin orange(autumn), apple(Hong-Ok), cherry tomato, tomato and water melon. Whereas, on the antioxidant efficiency, tomato showed the highest free radical scavenging effect followed by orange(summer), cherry tomato, mandarin orange(autumn), apple(Aori) red grape(Cambell Early:Sung-Ju), kiwi fruit and water melon. The amount of pheonlic components of red wine was 2 times of that of fermented sugar added grape juice, however, the antioxidant efficiency of fermented sugar added grape juice was almost the same as that of red wine. It was found that no clear relationship could be shown between the content of phenolic component and antioxidant capacity of fruit juices and fermented red grape juices. The fruit juices from tomato, orange, cherry tomato, mandarin orange, red grape and fermented sugar added red grape juice showed high free radical scavenging effect and should be regarded as a valuable source of antioxidant.

• Archives of Pharmacal Research
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• v.19 no.2
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• pp.112-115
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• 1996

Some antioxidant phenolic compounds exhibit prooxidant activity mainly due to their abilities to reduce $Fe^{3+}\; to\; Fe^{2+}.$ Reducing ability and prooxidant activity of maltol, an antioxidant component of Korean red ginseng, were compared with those of pyrogallol. Maltol at 2 mM did not appreciably reduce$ Fe^{3+}\; to\; Fe^{2+}$ and also failed to reduce nitroblue tetrazolium. Stimulation of hydroxyl radical mediated-deoxyribose degradation by pyrogallol was maximal at 60 .mu.M. Maltol stimulated the deoxyribose degradation to a much less extent, and a similar stimulatory effect was observed at a concentration of more than 100-fold higher than that of pyrogallol. The stimulatory effect of maltol reached a plateau over 1 mM, suggesting the removal of hydroxyl radicals by excess maltol. In bleomycin-$Fe^{3+}$-DNA assay, maltol at 2 mM produced a 2.5-fold increase of the iron-bleomycin-dependent DNA degradation over the basal value, whereas pyrogallol at 10 .mu.M accelerated DNA degradation by ca. 10-fold. Furthermore, maltol inhibited $Fe^{2+}$-stimulated DNA degradation by bleomycin. These results strongly suggested that maltol is an antioxidant with little prooxidant activity.

• Horticulture, Environment, and Biotechnology : HEB
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• v.59 no.6
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• pp.919-927
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• 2018

To compare the antioxidant properties and flavonols in various parts; dry skin (DS) and edible portion (EP), of 8 red onions (Allium cepa L, ROs), total content of phenolics (TPC), flavonoids (TFC), and anthocyanins (TAC) and DPPH radical scavenging properties were estimated and the content of six flavonols were quantified by HPLC-PDA analysis. The major component of DS and EP of RO was quercetin and quercetin-4'-glucoside, respectively. Score plots of the PCA and PLS-DA were segregated by flavonols content and antioxidant properties according to the EP and DS of ROs. Loading plot of the PCA showed that the quercetin and sum of flavonol content were highly correlated with antioxidant activity of ROs. Therefore, flavonol content and antioxidant activity can be used as markers for distinct parts of ROs.

• The Korean Journal of Food And Nutrition
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• v.35 no.1
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• pp.16-33
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• 2022

The quality characteristics and antioxidant activity of Tteokbokkidduk alone or supplemented with 3%, 6%, 9%, and 12% wheat bran powder were assessed, to increase use of the wheat bran by-product of wheat milling. The moisture content, pH, and starch elution of Tteokbokkidduk increased with increasing wheat bran powder, while the water absorption rate did not. The L color value decreased and the a and b values increased with increasing wheat bran powder. Scanning electron microscopy of Tteokbokkidduk prepared with 0% and 3% wheat bran powder revealed uniform pore size distribution. In terms of texture profile analysis, hardness and chewiness increased, while cohesiveness decreased with increased content of wheat bran powder. Acceptance was highest for samples with 6% wheat bran powder. Quantitative description analysis (QDA) revealed increased brownness, roughness, nutty, bitterness, astringency, savory character, and hardness, and decreased adhesiveness, springiness, and chewiness with increased wheat bran powder. Principal component analysis (PCA) revealed highest overall acceptance of samples prepared with 6% wheat bran powder, reflecting the relatively low values of detrimental sensory characteristics. Antioxidant activities of Tteokbokkidduk increased as wheat bran powder content increased. The addition of 6% wheat bran powder resulted in excellent Tteokbokki in terms of acceptance, quality, and antioxidant activity.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.309-309
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• 2022

This study investigated the antioxidant and yield properties of eight adzuki bean (Vigna angularis) cultivars under different mean temperature and sunshine hours in 2020 and 2021. The mean temperature in 2020 compared to 2021, which was normal, were lower during the pod extension and grain filling period. In addition, due to frequent rainfall during the vegetative perio d in 2020, there were fewer hours of sunshine compared to 2021. The Adzuki Bean yield in 2020 was about 13% lower than that in 2021 due to the decreased number of pods per plant and 100 seeds weight. The stability of yields was higher in 'Hongda' and 'Hongjin' than in 'Arari', which is the most cultivated in Korea. Also, the yields of these varieties were all higher than those of 'Arari' varieties for two years. Compared to 2021, in 2020, when weather conditions were not favorable, both antioxidant components and activity were higher. The cultivar 'Hongda' was a higher antioxidant component and activity than others for two years. The results suggested that the antioxidant component and activity were good in 2020 with about 13% decrease in yield compared to a normal year in 2021 due to mean temperature and sunshine hours.