• Membrane Journal
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• v.19 no.2
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• pp.89-95
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• 2009

A comb-like copolymer consisting of a poly(vinyl chloride) backbone and poly(hydroxy ethyl acrylate) side chains, i.e. PVC-g-PHEA, was synthesized through atom transfer radical polymerization (ATRP). This comb-like copolymer was crosslinked with 4,5-imidazole dicarboxylic acid (IDA) via the esterification of the -OH groups of PHEA in the graft copolymer and the -COOH groups of IDA. Upon doping with phosphoric acid (PA, $H_3PO_4$) to form imidazole-PA complexes, the proton conductivity of the membranes continuously increased with increasing PA content. A maximum proton conductivity of 0.011 S/cm was achieved at $100^{\circ}C$ under anhydrous conditions. The PVC-g-PHEA/IDA/PA complex membranes exhibited good mechanical properties, i.e. 575 MPa of Young's modulus, as determined by a universal testing machine (UTM). Thermal gravimetric analysis (TGA) shows that the membranes were thermally stable up to $200^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.9
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• pp.1334-1341
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• 2014

To examine the biological activity of polysaccharide extracted from cultured mycelia of Schizophyllum commune, we determined anti-complementary activity and nitric oxide production as a measure of immunological activity, anti-lipidperoxidation and hydroxy radical scavenging activity as a measure of antioxidative activity, tyrosinase inhibitory activity, anti-microbial activity, and transdermal flux of polysaccharide extracted from cultured mycelia of S. commune. Polysaccharide extracted from S. commune activated the complementary system and produced nitric oxide in RAW 264.7 macrophages. Antioxidant activities as malondialdehyde values were $49.5{\pm}0.7$, $39.7{\pm}1.7$, $39.2{\pm}1.2$, and $2.6{\pm}0.5nM/mL$ for control, extracellular polysaccharide extracted from S. commune (SC-EP), ultrafiltrated polysaccharide extracted from S. commune (SC-UP), and butylated hydroxytoluene, respectively. Hydroxy radical scavenging activity ($IC_{50}$) of SC-UP and mannitol were 3.32 and 1.66 mg/mL, respectively. Tyrosinase inhibitory activities of SC-UP, arbutin, and kojic acid were 19.9%, 31.8%, and 99.0%, respectively. Anti-microbial activities of SC-UP appeared to be low, and transdermal fluxes of SC-UP were 0.47%, 0.73%, and 1.20% after 3, 6, and 9 hr, respectively. These findings suggest that polysaccharide extracted from S. commune has potential immunological and antioxidant activities.

• Bulletin of the Korean Chemical Society
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• v.23 no.9
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• pp.1229-1258
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• 2002

This paper reports the photochemical reduction of benzil 1 to benzoin 2 and the reduction of 2 to hydrobenzoin 4 in deoxygenated solvents in the presence of triethylamine (TEA) and/or TiO2. Without TEA or TiO2, the photolysis of 1 resulted in very low yield of 2. The presence of TEA or TiO2 increased the rate of disappearance of 1 and the yield of 2, which were further increased considerably by the presence of water. The photoreduction of 1 to 2 proceeds through an electron transfer to 1 from TEA or hole-scavenged excited TiO2 followed by protonation. In the reaction medium of 88 : 7 : 2 : 3 CH3CN/CH3OH/H2O/TEA with 2.5 $㎎/m{\ell}$ of TiO2, the yield of 2 was as high as 85 % at 50 % conversion of 1. The photolysis of 2 in homogeneous media resulted in photo-cleavage to benzoyl and hydroxybenzyl radicals, which are mostly converted to benzaldehyde. The reduction product 4 is formed in low yield through the dimerization of hydroxybenzyl radicals. The addition of TEA increased the conversion rate of 2 and the yield of 4 significantly. This was attributed to the scavenging effect of TEA for benzoyl radical to produce N,N-diethylbenzamide and the photoreduction of benzaldehyde in the presence of TEA. The ratio of $(\pm)$ and meso isomers of 4 obtained from the photochemical reaction is about 1.1. This ratio is the same as that from the photochemical reduction of benzaldehyde in the presence of TEA. In the TiO2-sensitized photochemical reduction of 2, meso-4 was obtained in moderate yield. The reduction of 2 to 4 proceeds through two consecutive electron/proton transfer processes on the surface of the photocatalyst without involvement of ${\alpha}-cleavage$. The radical 11 initially formed from 2 by one electron/proton process can also combine with hydroxy methyl radical, which is generated after hole trapping of excited TiO2 by methanol, to produce 1,2-diphenylpropenone after dehydration reaction.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.230-234
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• 2007

Oxygen is required for many important aerobic cellular reactions, it may undergo electrontransfer reactions, which generate highly reactive membrane-toxic intermediates (reactive oxygen species, ROS), such as hydrogen peroxide, singlet oxygen, superoxide radical, hydroxyl radical, hydroperoxyl radical, hydroxy ion. Various mechanisms are available to protect cells against damage caused by oxidative free radicals, including scavenging enzyme systems such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). This antioxidant defense system is a very complex and finely tuned system consisting of enzymes capable of detoxifying oxygen radicals as well as low molecular weight antioxidants. In addition, repair and turnover processes help to minimize subcellular damage resulting from free radical attack. $H_2O_2$,one of the major ROS, is produced at a high rate as a product of normal aerobic metabolism. The primary cellular enzymatic defense systems against $H_2O_2$ are the glutathione redox cycle and catalase. From Northern blot analysis of total RNAs from cultured cell with $H_2O_2$ treatment, various results were obtained. Expression of Cu/Zn SOD decreased when cell passage increased, but the level of the Cu/Zn SOD was scarcely expressed in 35 passage.

• Journal of Korean Medicine for Obesity Research
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• v.20 no.1
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• pp.10-19
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• 2020

Objectives: Oxidative stress-mediated neuroinflammation has been supposed as a crucial factor that contributes to the pathogenesis of many neurodegenerative diseases. In this study, we aimed to investigate the protective activity against oxidative stress and neuroinflammation of protocatechuic acid (PA), active phenolic compound from Momordica Charantia. Methods: Protective activity of PA from oxidative stress was performed under in vitro conditions. Our study investigated the protective mechanism of PA from neuroinflammation in cellular system using C6 glial cell. To investigate the improvement the effects on oxidative stress and neuroinflammation, we induced oxidative stress by H₂O₂ (100 μM) stimulation and induced neuroinflammation by treatment with lipopolysaccharide (LPS) (1 ㎍/mL) and interferon-gamma (IFN-γ) (10 ng/mL) in C6 glial cells. Results: PA showed strong radical scavenging effect against 1,1-dipenyl-2-picrylhydrazyl, hydroxy radical (·OH) and nitric oxide (NO). Under oxidative stress treated by H₂O₂, the result showed the increased mRNA expressions of oxidative stress markers such as nuclear factor-kappaB (NF-κB), cyclooxygenase (COX-2) and inducible nitric oxide (iNOS). However, the treatment of PA led to reduced mRNA expressions of NF-κB, COX-2 and iNOS. Moreover, PA attenuated the production of interleukin-6 and scavenged NO generated by both endotoxin LPS and IFN-γ together. Furthermore, it also reduced LPS and IFN-γ-induced mRNA expressions of iNOS and COX-2. Conclusions: In conclusion, our results collectively suggest that PA, phenolic compound of Momordica Charantia, could be a safe anti-oxidant and a promising anti-neuroinflammatory molecule for neurodegenerative diseases.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.1
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• pp.1-7
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• 2010

This study was carried out to investigate total polyphenol contents, total flavonoid contents and antioxidative activities of the methanol extracts from dried Citrus sunki and C. unshiu peels. The dried C. sunki peels displayed higher total polyphenol and flavonoid contents for older dried peels. In contrast, the dried C. unshiu peels displayed higher total polyphenol contents for more recently dried and displayed high total flavonoid contents by order of 2007, 2008 and 2006. DPPH radical scavenging activities of dried C. sunki peels were high by order of 2007 (0.25 mg/mL exception), 2006 and 2008, but C. unshiu peels could not confirm clear regularity. In particular, the dried C. sunki (2008, exception) and C. unshiu peels displayed very high activities of more than 86% in 1.0 mg/mL. Alkyl radical scavenging activities of dried C. sunki peels were higher for older dried peels (2007, 1.0 mg/mL exception), and that of dried C. unshiu peels were higher for more recently dried in below 0.5 mg/mL but were higher for older peels in 1.0 mg/mL. Hydrogen peroxide scavenging activities of dried C. sunki peels were higher for older peels (2007, 2.5 mg/mL exception), on the other hand, dried C. unshiu were higher for more recently dried. In particular, dried C. unshiu peels displayed high activities of more than 85% in 2.5 mg/mL. Hydroxyl radical scavenging activities of dried C. sunki and C. unshiu peels displayed low activities compared to other reactive oxygen species as the range of $49.9\pm2.2\sim63.5\pm0.9$% in 1.0 mg/mL.

• Korean Journal of Pharmacognosy
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• v.36 no.4 s.143
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• pp.318-323
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• 2005

The leaves (KPL) of Kalopanax pictus (KP) are used as a vegetable or a functional food in Korean society. The stem bark (Kalopanacis Cortex, KPS) has been traditionally used to treat neurotic pain, rheumatoid arthritis and diabetic disease. This research was undertaken to demonstrate that the leaf extract of KP (KPL) has also the antinociceptive and antiinflammatory effects like the extract (KPS) of Kalopanacis Cortex and to compare the activity levels of several extracts obtained from KP. Antinociceptive and antiinflammatory effects were measured against the extracts described as followings; KPL-1 (the MeOH extract obtained from the leaf shoot of KP collected on May), KPL-2 (the MeOH extract from KP collected on June), KPL-3 (the MeOH ectract from KP with no thorns), KPS-1 (MeOH extract from KPS of a Korean habitat), KPS-2 (MeOH extract from KPS of a Chinese habitat). The antimociceptive test undertaken by acetic acid-induced writhing, hot plate-, and tail-flick methods using mice. The anti-inflammatory test was also undertaken by measuring the edema in the carrageenan-induced test. The order of activity potency in the antinociceptive and antiinflammatory assays was commonly shown as followings: KPL-3>KPS>1>KPS-2>KPL-1>KPL-2. This order was also observed in acetic acid-induced vascular permeability test. The antiinflammatory activity in carrageenan-induced assay was also observed as the following order: KPL-3>KPS- 1>PS-2>KPL-1>KPL-2. In addition, adjuvant-induced rats were used for a model to assess the oxidative stress. Treatment of the rat with the extracts reduced serum thiobarbituric acid-reactive substances (TBARS), hydroxy radical(OH) and superoxide dismutase(SOD) activity caused by FCA together together with the inhibition of hepatic TBARS level and lipofuscin content. The above finding suggests that the leaf extract has the antinociceptive and antinflammatory activity. It is also suggested that KPL-3 with more potent activity than other tested extracts could be developed for a new available biomaterial.

• Korean Journal of Pharmacognosy
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• v.47 no.3
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• pp.204-210
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• 2016

Phytochemical investigation of the 80% MeOH extract from the stems of Lagerstroemia indica resulted in the isolation of eighteen compounds; four norsesquiterpenes, fourteen phenolic derivatives. Their chemical structures were characterized by spectroscopic methods to be tachioside (1), isotachioside (2), 2,4,6-trimethoxyphenyl ${\beta}$-D-glucopyranoside (3), gallic acid 4-methyl ether (4), protocatechuic acid (5), gallic acid (6), vanillic acid (7), vanillin (8), 2-methoxy-5-hydroxymethyl-phenyl-1-O-(6"-galloyl)-${\beta}$-D-glucopyranoside (9), 2,4,6-trimethoxyphenol-1-O-${\beta}$-D-(6'-O-galloyl)-glucopyranoside (10), 4-hydroxy-3-methoxyphenyl-1-O-(6'-O-galloyl)-${\beta}$-D-glucopyranoside (11), vomifoliol (12), vomifoliol 9-O-${\beta}$-D-glucopyranoside (13), 6R,9R-3-oxo-${\alpha}$-ionol-9-O-${\beta}$-D-glucopyranoside (14), dihydrophaseic acid 4'-O-${\beta}$-D-glucopyranoside (15), ${\beta}$-hydroxypropiovanillone 3-O-${\beta}$-D-glucopyranoside (16), myrciaphenone A (17), and coumaric acid (18). Compounds 1-5 and 7-18 were isolated for the first time from this plant. Compounds 1-18 were investigated for their antioxidant properties using DPPH and ABTS radical scavenging capacity assay, $Fe^{2+}$ chelating, and FRAP assay. It was found that 4, 6, and 11 possessed the highest antioxidant capacities.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.463-470
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• 2009

Sixteen antioxidative active compounds isolated from the EtOAc layer of MeOH extracts of kochujang, Korean fermented red pepper paste, were structurally elucidated as fumaric acid, methyl succinate, succinic acid furan-2-yl ester methyl ester (gochujangate, a novel compound), 2-hydroxy-3-phenylpropanoic acid, 3,4-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 6,7-dihydroxy-2H-chromen-2-one (esculetin), caffeic acid, cis-p-coumaric acid, trans-p-coumaric acid, daidzin, genistin, apigenin 7-O-$\beta$-D-apiofuranosyl($1{\rightarrow}2$)-$\beta$-D-glucopyranoside, apigenin 7-O-$\beta$-Dglucopyranoside, and quercetin 3-O-$\alpha$-L-rhamnopyranoside by mass spectrometry (MS) and nuclear magnetic resonance (NMR) experiments. These compounds were analyzed for the first time as antioxidants from kochujang.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1113-1118
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• 2010

The antioxidative activities and growth inhibitory effects of fermented soymilk (FS) by Bacillus subtilis KC-3 (KCCM 42923) in AGS human gastric adenocarcinoma cells were studied during fermentation at pH 5.5, 5.25 and 5.0. The pH of B. subtilis KC-3 from Cheonggukjang, decreased from 6.8 to 5.0 during the fermentation. The acidity decreased, but amino and ammonia type nitrogen contents increased significantly as pH decreased. FS at pH 5.0 (FS 5.0) exhibited the highest DPPH free radical scavenging activities among other samples. The hydroxy radical scavenging activity of FS 5.0 was found to be approximately 2.5 times higher than that of the non-fermented soymilk (NFS). The SOD-like activity of FS 5.0 was 32.1% at 1.0 mg/mL and 50.6% at 2.0 mg/mL compared to the NFS of 9.1% and 17.3%, respectively. FS, especially FS 5.0, showed increased anticancer effect in AGS human gastric adenocarcinoma cells. These results suggest that soymilk fermented by B. subtilis KC-3 has increased antioxidative activities and anticancer effects during fermentation (pH 6.0 to pH 5.0).