• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.2
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• pp.83-92
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• 2008

In this study, the antioxidative effects, inhibitory effects on tyrosinase and elastase and components of Fagopyrum esculetum extracts were investigated. Fagopyrum esculetum used for this study is hulls and dehulled seeds. The free radical(1,1-diphenyl-2-picrylhydrazyl radical, DPPH) scavenging activities($FSC_{50}$) and reactive oxygen species(ROS) scavenging activities($OSC_{50}$) of extract/fractions from Fagopyrum esculetum were measured. The aglycone($3.5{\pm}0.0{\mu}g/mL$) and ethyl acetate fractions($0.2{\pm}0.1{\mu}g/mL$) of hulls showed the most effective scavenging activities. The protective effects on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The ethyl acetate fraction exhibited the most prominent cellular protective effect(${\tau}_{50},\;771.7{\pm}9.9 min$ at 10 ${\mu}g/mL$). The inhibitory effect of aglycone fraction of hull and dehulled seeds on tyrosinase were examined ($53.6{\pm}0.5{\mu}g/mL,\;35.6{\pm}0.4{\mu}g/mL$, respectively). And The inhibitory effect of aglycone fraction of hull and dehulled seeds on elastase were investigated($3.7{\pm}0.4{\mu}g/mL\;and\;6.0{\pm}0.7{\mu}g/mL$ respectively). But 50% ethanol extract rarely exhibited the inhibitory activity on tyrosinase and elastase. (+)-Catechin and (-)-epicatechin were contained in ethyl acetate fraction of dehulled seeds. And ethyl acetate fraction of hull contains flavonoids of hyperin, quercetin, rutin and so on. These results indicate that extract/fractions of Fagopyrum esculentum can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. Fagopyrum esculentum extract could be used as a new cosmeceutical for whitening and anti-wrinkle products.

• Applied Biological Chemistry
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• v.35 no.4
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• pp.276-280
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• 1992

Quantutative analysis of catechins by HPLC was studied. When the mobile phase was switched from the conventional(AOAC) Methanol, Acetonitril and Acetic acid solution in $H_2O$ to 0.06% Phosphate solution with Acetonitrile, N,N-Dimethyl formamide, and Ethyl acetate, retention time could be reduced from 45 min to 28 min, especially, we obtained sharper chromatogram of the compounds, either (-)EGCG or (-)ECG, which resulted in minimization of analytical erros. CVs of retention time $(0.32{\sim}3.97%)$ and peak area $(1.61{\sim}7.01%)$ indicated that the data were more reliable. Content of catechins in commerical teas analyzed by the method was $120.3{\sim}153.7\;mg/g$ in green teas which was about 4 times that in black tea.

• Korean Journal of Medicinal Crop Science
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• v.14 no.5
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• pp.267-272
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• 2006

Phytochemical study on the EtOAc fraction from the MeOH extract of the leaves of Cedrela sinensis led to the isolation of five known phenolic compounds (1-5), whose structures were identified as (+)-catechin (1), $kaempferol-3-0-{\alpha}- L-rhamnopyranoside$ (2), quercetin (3), $quercetin-3-O-{\alpha}-L-rhamnopyranoside$ (4), and $quercetin-3-O-{\beta}-D-glucopyranoside$ (5), respectively, by comparing their spectral $(uv,\;JR,\;IH\;and\;^{13}C-NMR,\;and\;ESI-MS)$ and physicochemical data with those reported in the literature. Among the isolated compounds (1-5), compounds 1 and 3-5 exhibited significant DPPH radical scavenging effects with $IC{_50}$ values ranging from $21.3{\pm}1.4\;to\;38.1{\pm}3.2 {\mu}M$ as well as superoxide anion radical scavenging effects with $IC{_50}$ values ranging from $9.4{\pm}0.7\;to\;21.2{\pm}3.6 {\mu}M$. Furthermore, compounds 1 and 3-5 also exhibited considerable inhibitory effects on LDL peroxidation induced by either $CU^{2+}$ or AAPH with $IC{_50}$ values ranging from $1.4{\pm}0.4\;to\;11.9{\pm}1.4\;{\mu}M$. These results indicated that flavonoids are the major constituents of C. sinensis and considered to be antioxidant principles of this plant.

• Journal of Nutrition and Health
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• v.50 no.5
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• pp.415-425
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• 2017

Purpose: Many studies have suggested that neuronal cells protect against oxidative stress-induced apoptotic cell death by polyphenolic compounds. We investigated the neuroprotective effects and the mechanism of action of Momordica charantia ethanol extract (MCE) against $H_2O_2-induced$ cell death of human neuroblastoma SK-N-MC cells. Methods: The antioxidant activity of MCE was measured by the quantity of total phenolic acid compounds (TPC), quantity of total flavonoid compounds (TFC), and 2,2-Diphenyl-1-pycrylhydrazyl (DPPH) radical scavenging activity. Cytotoxicity and cell viability were determined by CCK-8 assay. The formation of reactive oxygen species (ROS) was measured using 2,7-dichlorofluorescein diacetate (DCF-DA) assay. Antioxidant enzyme (SOD-1,2 and GPx-1) expression was determined by real-time PCR. Mitogen-activated protein kinases (MAPK) pathway and apoptosis signal expression was measured by Western blotting. Results: The TPC and TFC quantities of MCE were 28.51 mg gallic acid equivalents/extract g and 3.95 mg catechin equivalents/extract g, respectively. The $IC_{50}$ value for DPPH radical scavenging activity was $506.95{\mu}g/ml$ for MCE. Pre-treatment with MCE showed protective effects against $H_2O_2-induced$ cell death and inhibited ROS generation by oxidative stress. SOD-1,2 and GPx-1 mRNA expression was recovered by pre-treatment with MCE compared with the presence of $H_2O_2$. Pre-treatment with MCE inhibited phosphorylation of p38 and the JNK pathway and down-regulated cleaved caspase-3 and cleaved PARP by $H_2O_2$. Conclusion: The neuroprotective effects of MCE in terms of recovery of antioxidant enzyme gene expression, down-regulation of MAPK pathways, and inhibition apoptosis is associated with reduced oxidative stress in SK-N-MC cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.3
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• pp.198-204
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• 1988

This study was aimed at obtaining elementary data on enzymatic browning of potato and potato products and examining the inhibitory method of browning. Therefore, we extracted polyphenol oxidase from potatoes(Solanum tubersum L.), and investigates its general properties and inhibiting effects of its activity with the different concentrations of sulfites($Na_2S_2O_4,\;Na_2SO_3{\cdot}7H_2O,\;NaHSO_3$). The optimum pH and temperature of polyphenol oxidase were observed to be 6.5 and $37^{\circ}C$ respectively. The polyphenol oxidase at PH5 was very stable, and the activity of polyphenol oxidase between pH $5.0{\sim}9.0$ was estimated to be relatively high, showing $72{\sim}75%$ of its activity at pH5. The polyphenol oxidase was very stable when heated at $40^{\circ}C$ for one hour, and almost 50% of enzyme activity was decreased when heated at $70^{\circ}C$ for twelve minutes. At 0.1mM concentrating of sulfites the relative activity of polyphenol oxidase was 98% in all the three cases of sulfites. Thus sulfites at 0.1mM concentration was found to have little inhibiting effect on polyphenol oxidase activity. At 1mM concentration of sulfites $NaHSO_3$ showed the lowest 36% relative activity among the three. At 5mM concentration of sulfites, the relative activity of $Na_2SO_3{\cdot}7H_2O$ was the lowest 14%.

• Journal of Life Science
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• v.28 no.6
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• pp.708-717
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• 2018

The antioxidant activity and protective effects of a hot water extract from the Stauntonia hexaphylla fruit (WESHF) were investigated in vitro and in vivo. The total polyphenol and flavonoid contents of WESHF were $16.13{\pm}0.27mg$ gallic acid equivalent/g and $4.7{\pm}0.80mg$ catechin equivalent/g, respectively. In addition, the DPPH radical-scavenging activity ($SC_{50}$) and the Oxygen Radical Absorbance capacity of WESHF were $63.62{\pm}4.10{\mu}g/ml$ and $90.63{\pm}5.29{\mu}M$ trolox equivalent/g, respectively. The hepatoprotective effect of WESHF against hydrogen peroxide-induced oxidative damage was investigated. $H_2O_2$-induced liver damage on HepG2 cells was prevented by $200{\mu}g/ml$ of WESHF. Furthermore, to investigate the protection mechanism of WESHF on hydrogen peroxide-induced cytotoxicity in HepG2 cells, pre-treatment with $200{\mu}g/ml$ of WESHF significantly attenuated a decrease in the activities of CAT, SOD, GR, and GPx. The hepatoprotective activity of WESHF was evaluated in an experimental model of hepatic damage induced by acetaminophen (APAP). The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly decreased in the livers of mice treated with 200 mg/kg of WESHF compared to the APAP-treated group. The lipid peroxidation level, which increased after APAP administration, was significantly reduced in the WESHF group. In addition, histological examinations of the liver showed the same protective effect of WESHF treatment. Based on these findings, it is suggested that WESHF has potent hepatoprotective effects, and the mechanism that causes this type of protection could be related to antioxidant pathways.

• The Korean Journal of Food And Nutrition
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• v.15 no.2
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• pp.119-125
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• 2002

Phytoestrogens are non-steroidal compounds fecund In a variety of plants, which exert estrogenic effects in animals. In this study, the physico-chemical properties of Iranian black pomegranate extract and its products as preliminarily research for the developing of natural estrogen supplement were evaluated. The chemical components of Iranian black pomegranate extracts and its product (Forever 120) were analyzed. Proximate compositions of pomegranate extracts were as follows; crude lipid 0.4%, crude protein 0.9%, crude ash 1.4% and carbohydrate 42.0%. Major amino acids of pomegranate extracts are glutamic acid (1310.0ppm), aspartic acid (896.2ppm), arginine (877.7ppm) and phenylalanine (57.5ppm). Fatty acid compositions of pomegranate extract 1ibid extracted by chloroform-methanol (2:1) were myristic (13.1%), stearic (69.4), oleic acid (6.8%) and palmitic acid (8.3%). Mineral elements were ferrous (6640.0ppm) and potassium (2550.8ppm). Vitamins were composed of ascorbic acid(20.0mg/100g), Vit. B$_1$(0.12mg/100g) and niacin (0.80mg/100g). 20 phytoestrogens and 20 estrogens of pomegranate extracts were detected Daidzein (0.29ppm), quercetin (9.75ppm) genistein (0.29ppm) and 17 $\beta$ -estradiol(0.15ppm). Above the chemical components of pomegranate extracts were compared with that of pomegranate its product or other isoflavon concentrates.

• Journal of Korea Foresty Energy
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• v.19 no.2
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• pp.93-101
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• 2000

Wood of Robinia pseudoacacia and bark of Populus alba$\times$P. glandulosa, Fraxinus rhynchophylla and Ulmus davidiana var. japonica were collected and extracted with acetone-water(7:3, v/v) in glass jar to examine whether its bioactive compounds exist. The concentrated extracts were fractionated with hexane, chloroform, ethylacetate and water, and then freeze-dried for column chromatography and bioactive tests. The isolated compounds were sakuranetin-5-O-$\beta$-D-glucopyranoside from Populus alba $\times$Pl glandulosa, 4--ethyoxy-(+)-leucorobinetinidin frm R. pseudoacacia and fraxetion from F. rhynchophylla and were characterized by $^1H$ and$^{13}C $ NMR and positive FAB-MS. Decay-resistant activity was expressed by weight loss ratio and hyphae growth inhibition in the wood dust agar medium inoculated wood rot fungi. R. pseudoacacia showed best anti-decaying property in both test and its methanol untreated samples, indicating higher activity than methanol treated samples in hyphae grwoth test. In antioxidative test, $\alpha$-tocopherol, one of natural antioxidants, and BHT, one of synthetic antioxidants, were used as references to cmpare with the antioxidant activities of the extacted fractions. Ethylacetate fraction of F. rhynchophylla bark indicated the hightest activity in this test and all fractions of R. pseudiacacia extractives also indicated higher activities compared with the other fractions. In the isolated compounds, aesculetin isolated from F. rhynchophylla bark showed best activity and followed by robonetinidin from R. pseudoacaica.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.71-84
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• 2003

The metallic shell of soil-steel structures are so weak in bending moment that it should sustain the applied load by the interaction of the backfill soil around the structures. The shell can be subjected to excessive bending moment during side backfilling or under live-load when the soil cover is less than the minimum value. The current design code specifies the allowable deformation and Duncan(1979) and McGrath et al.(2001) suggested the strength analysis methods to limit the moments by the plastic capacity of the shell. However, the allowable deformation is an empirically determined value and the strength analysis methods are based on the results of FE analysis, hence the experimental verification is necessary. In this study, the full-scale tests were conducted on the high-profile arch to investigate its behaviors during backfilling and under static live-loads. Based on the measurements, the allowable deformation of the tested structure could be estimated to be 1.45% of rise, which is smaller than the specified allowable deformation. The comparison between the measurements and the results of two strength analyses indicate that Duncan underestimates the earth-load moment and overestimates the live-load moment, while McGrath et al. predicts both values close to the actual values. However, as the predicted factors of safeties using two methods coincide with the actual factor of safety, it can be concluded that both methods can predict the structural stability under live-loads adequately when the cover is less than the minimum.