• Natural Product Sciences
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• v.11 no.3
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• pp.150-154
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• 2005

The radical scavenging effect of the MeOH extract of Fraxini Cortex on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical was examined. The $CH_2Cl_2$-and n-BuOH-soluble fractions of MeOH extract showed the promising DPPH radical scavenging effects, and further purified by silica gel, Sephadex LH-20 column chromatography, and reversed-phase C-18 MPLC to yield five coumarins, esculetin (1), fraxidin (2), fraxetin (3), fraxidin $8-O-{\beta}-D-glucopyranoside$ (fraxin methyl ether) (5), esculin (6), and a secoiridoid oleuropein (4), and a coumarin-secoiridoid escuside (7). Compounds 1, 3, and 4 showed potent DPPH radical scavenging effects, exhibiting $IC_{50}$ values of 14.68, 9.64, and $22.03\;{\mu}M$, respectively. Compounds 6 and 7 also showed moderate effects with $IC_{50}$ values of 147.79 and $72.73\;{\mu}M$, respectively. L-Ascorbic acid was used as a positive control and exhibited the $IC_{50}$ value of $50.31\;{\mu}M$.

• Archives of Pharmacal Research
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• v.27 no.4
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• pp.454-459
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• 2004

The present study investigated the effects of gossypin, 3,3',4',5,7,8-hexahydroxyflavone 8-glucoside, on the toxicity induced by oxidative stress or $\beta$-amyloid ($A_{\beta}$) in primary cultured rat cortical cells. The antioxidant properties of gossypin were also evaluated by cell-free assays. Gossypin was found to inhibit the oxidative neuronal damage induced by xanthinelxanthine oxidase or by a glutathione depleting agent, D,L-buthionine (S,R)-sulfoximine. In addition, gossypin significantly attenuated the neurotoxicity induced by $A_{{\beta}(25-35)}$. Furthermore, gossypin dramatically inhibited lipid peroxidation initiated by $Fe^{2+}$ and ascorbic acid in rat brain homogenates. It also exhibited potent radical scavenging activity generated from 1 ,1-diphenyl-2-picrylhydrazyl. These results indicate that gossypin exerts neuroprotective effects in the cultured cortical cells by inhibiting oxidative stress- and $A_{\beta}$-induced toxicity, and that the antioxidant properties of gossypin may contribute to its neuroprotective actions.

• Preventive Nutrition and Food Science
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• v.7 no.3
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• pp.310-316
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• 2002

Extracellular cyclodextrin glucanotransferase (CGTase) from Paenibacillus sp. JK-12 was purified through sev-eral purification steps consisting of ammonium sulfate precipitation and chromatographies on DEAE-sephadex A-50 and Mono QIM HR5/5. The purified CGTase exhibited a single band on SDS-PAGE and was estimated to be approximately 82 kDa. The isoelectric point of the enzyme was 7.2 as determined by isoelectric focusing. The CGTase from Paenibacillus sp. JK-12 had a transglucosylation activity at the C-2 position of L-ascorbic acid. The optimum pH and temperature for the CGTase activity were 8.0 and 5$0^{\circ}C$, respectively. The enzyme activity was stable from pH 6.0 to 9.() and at temperatures up to 55$^{\circ}C$ at pB 8.0, having 80% residual activity. The activity of the CGTase was strongly resistant to metals such as A $g^{+}$ and $Ba^{2+}$ but slightly inhibited by H $g^{+}$, N $i^{2+}$ and $Mg^{2+}$. The enzymeproduced $\alpha$ -cyclodextrin ($\alpha$-CD) and $\beta$-CD as the main products from starch, but not ${\gamma}$-CD.X>-CD.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.251-256
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• 2008

Changes in antioxidant activity of Rubus coreanus fruit of 3 clones (S13, S114, and S16), which were selected from different sites, were studied at different ripening stages. Antioxidant activities (tree radical scavenging activity and reducing power) were determined and their relationships to total phenolic contents and ascorbic acid were analyzed. The highest tree radical scavenging activities of 3 clones (S13, S14, and S16) were 79.39, 75.80, and 81.16% at $125\;{\mu}g/mL$, respectively. In general, the antioxidant activity and the related parameters, including total phenolic content and vitamin C content decreased during fruit ripening. Total phenolic contents of the R. coreanus fruits (S13, S14, and S16) were correlated with tree radical scavenging activity ($R^2=0.8114$, 0.9186, and 0.9714). These results improve knowledge of the effect of ripening on the antioxidant activity and related compounds contents that could help to establish the optimum R. coreanus fruit harvest data for various usages.

• Biomedical Science Letters
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• v.22 no.1
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• pp.1-8
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• 2016

Several studies have investigated the various effects of dexamethasone (Dex) on the proliferation and differentiation of mesenchymal stem cells (MSCs). Previously, we reported that co-treatment with L-ascorbic acid 2-phosphate and fibroblast growth factor (FGF)-2 maintained differentiation potential in MSCs through expression of hepatocyte growth factor (HGF). In this study, we investigated the effects of co-treatment with FGF-2 and Dex on the proliferation and differentiation potential of MSCs during a 2-month culture period. Co-treatment with FGF-2 and Dex increased approximately a 4.7-fold higher accumulation rate of MSC numbers than that by FGF-2 single treatment during a 2-month culture period. Interestingly, co-treatment with FGF-2 and Dex increased expression of HGF and maintained adipogenic differentiation potential during this culture period. These results suggest that co-treatment with FGF-2 and Dex preserves the proliferation and differentiation potential during long-term culture.

• The Korean Journal of Food And Nutrition
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• v.28 no.3
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• pp.446-457
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• 2015

최근 식품에 첨가하는 합성 항산화제가 생체효소의 활성을 억제하고, 암을 유발시키는 등의 안정성에 문제가 되는 것으로 보고되면서 천연 식물자원으로부터의 항산화 물질을 개발하고자 하는 연구가 활발하게 진행되고 있다. 느릅나무의 껍질인 유근피는 항산화 효과가 매우 우수한 것으로 보고되고 있어서, 천연 항산화제로 유근피 에탄올 추출물을 0, 0.05, 0.1, 0.2%로 약과에 첨가하여 합성 항산화제인 BHT와 천연 항산화제인 L-ascorbic acid를 0.02%로 첨가한 약과와 저장기간에 따른 품질특성과 지질산패 정도를 비교하였다. 유근피의 첨가량이 증가할수록 산패취와 경도는 감소하였고, 반면에 수분활성도, 팽화도, 관능평가 등은 증가하였다. 특히 유근피를 첨가함에 따라 약과의 명도가 감소한 것으로 나타났는데, 이는 약과의 메일라드 반응에 의한 갈색물질인 멜라노이딘류의 생성 때문으로 추정된다. 또한 약과의 저장 기간이 증가함에 따라서 경도, 색도, 산패취 등이 증가하였고, 반면에 수분활성도와 팽화도, 색, 맛, 조직감, 전반적인 기호도 등의 관능적 특성은 감소하였다. 유근피가 약과의 저장성에 미치는 영향을 살펴보기 위해서 산가와 과산화물가를 측정하여 실험한 결과, 유근피를 첨가한 약과는 첨가하지 않은 약과에 비해서 지질산화가 적게 일어나, 약과의 저장성을 증가시켜 주는 것으로 나타났다. 관능적인 특성을 비롯한 품질특성과 지질산패 정도를 평가한 결과, 유근피 추출물을 0.1% 첨가한 약과가 가장 좋을 것으로 평가되었다.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.2
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• pp.217-223
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• 1998

Oxygen-derived free radicals have been implicated in many important functions in the biological system. Electrical field stimulation (EFS) causes arterial relaxation in animal models. We found that EFS applied to neither muscle nor nerve but to Krebs solution caused a relaxation of rat aorta that had been contracted with phenylephrine. In the present study, therefore, we investigated the characteristics of this EIRF (electrolysis-induced relaxing factor) using rat isolated aorta. Results indicated that EIRF acts irrespective of the presence of endothelium. EIRF shows positive Griess reaction and is diffusible and quite stable. EIRF-induced relaxation was stronger on PE-contracted aorta than on KCl-contracted one, and inhibited by the pretreatment with methylene blue. Zaprinast, a cGMP-specific phosphodiesterase inhibitor, potentiated the EIRF-induced relaxation. $N^G-nitro-L-arginine$, NO synthase inhibitor, did not inhibit the EIRF-induced relaxation. Deferroxamine, but not ascorbic acid, DMSO potentiated the EIRF-induced relaxation. These results indicate that electrolysis of Krebs solution produces a factor that relaxes vascular smooth muscle via cGMP-mediated mechanism.

• The Korean Journal of Community Living Science
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• v.15 no.4
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• pp.11-16
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• 2004

This study was conducted to find the powerful free radical scavenging effect in methanol extracts from 35 kinds of Korean medicinal plants obtained from the Plant Extract Bank as natural plant products. Antioxidant activity of the plant extracts was determined by measuring the scavenging effect of 1,1-diphenyl-2-picryl hydrazyl radical (DPPH). In the screening of plant extracts tested, at 200 ppm level, almost all plantex tracts showed significantly high antionidant activity. In the reinvestigation of 15 kinds of Korean medicinal plants at 50 ppm level selected as good sources with good free radical scavenging effect at 200 ppm level, the DPPH scavenging effects were similar to those of L-ascorbic acid in whole plant extract of Fragaria yezoensis (90.4％), in the plant stems and roots extract of Gingko biloba, and the leaves extract of Rhododendron mucronulatum var. ciliatum (90％). The fruits extract of Cornus officinalis showed the strongest antioxidant activity (95％). These results suggest that the methanol extracts from Korean medicinal plants can be a potential source of antioxidants that can be used to control oxidative stress in the body, But further study is needed to measure their safety for consumption

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.673-675
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• 2003

The antioxidant activities of methanol and dichloromethane extracts of eighteen salt marsh plants were tested by using 1,1-Diphenyl-2-picryl-hydrazyl(DPPH) at a $100{\mu}g/ml$ concentrations. The methanol extracts of four salt marsh plants(Rosa rugosa Thunberg, Erigeron annuus, Ixeris tamagawaensis kitamura, Artemisia capillaris Thunberg) were found to be most effective in DPPH radical scavenging activity. The DPPH radical scavenging effect of these plants was Artemisia capillaris Thunberg(88.67%), Rosa rugosa Thunberg(87.51%), Erigeron annuus(78.49%), Ixeris tamagawaensis kitamura(69.99%) in order and was comparable with that of natural antioxidant, L-ascorbic acid(96.64%). The next effective ones were the methanol extracts of Teragonia tetragonoides(58.66%) and the dichloromethane extracts of Artemisia capillaris Thunberg(54.67%) and the others did not show a considerable activity. These salt marsh plants were evaluated using the pyrogallol UV-VIS spectrophotometeric method to generate superoxide anion. Among them, the dichloromethane extracts of four salt marsh plants and the methanol extracts of fifteen ones were weak superoxide dismutase-like activities.

• Journal of Ginseng Research
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• v.14 no.2
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• pp.191-199
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• 1990

It has been well known that extended exposure to reactive oxygens causes severe damage to susceptible biomolecules. In this study, the effects of flavonoids including trifolin and kaempferol from Ginseng leaves on singlet oxygen induced photohemolysis of erythrocytes and free radical scavenging activities were investigated. Each flavonoid aglycone (5-50$\mu$M) such as kaempferol, quercetin or baicalein exhibited a high protective effect against the photohemolysis. They protected the cells by scavenging $^1O_2$ and free radicals Although the free radical scavenging activities of the flavonoid glycosides were not much lower than those of their corresponding aglycones, their insolubility into lipid bilayers of membrane made them less effective in preventing the photohemolysis induced by $^1O_2$. The $^1O_2$ and free radical scavenging activities of flavonoids were estimated by the decomposition of the flavonoid by $^1O_2$ and the bleaching of free radicals by the flavonoid, respectively. The solubilization of the flavonoid into micells or erythrocytes was deduced from spectrophotometric and microscopic observations. The cooperation of L-ascorbic acid and a flavonoid, and a possible involvement of lipoxygenase or cyclooxygenase in the photohemolysis mechanism were discussed.