• Applied Biological Chemistry
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• v.47 no.2
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• pp.258-264
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• 2004

Hypoglycemic effect of Schizandrae Fructus (SF) extract containing in Okchun-san was determined on 3T3-L1 fibroblasts and adipocytes by investigating insulin-like activity, insulin sensitizing activity and ${\alpha}-glucoamylase$ suppressing activity. SF were extracted by using 70% ethanol followed by XAD-4 column chromatography with a mixture solvent of methanol and water, and the fractional extractions were utilized for assaying hypoglycemic effect. No inhibition of ${\alpha}-glucoamylase$ activity of SF was observed. Insulin-like activity 3T3-L1 adipocytes was not shown by SF. A significant insulin sensitizing activity of SF extractions was observed in 3T3-L1 adipocytes, giving SF extractions with 1 ng/ml insulin to reach glucose uptake level increased by 50 ng/ml of insulin alone. When cells were treated with SF (Fr. 4 or 5) plus 1 ng/ml insulin, glucose uptake was increased more than seven times as compared to 1 ng/ml of insulin alone, suggesting that SF extracts increased GLUT4 content by enhancing insulin signaling. These data suggest that SF extracts (especially Fr. 4 and 5) contains an effective insulin sensitizing compounds for hypoglycemic activity in 3T3-L1 adipocytes.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.243-249
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• 2005

Esterification of lactic acid with alcohols catalyzed by Amberlyst-type ion exchange resins and sulfuric acid was carried out in a batch reactor with total /or partial recycle of distilled condensates, respectively. The esterification of lactic acid in the total-recycling reactor (n-butanol/lactic acid = 4, $100^{\circ}C$) was promoted by decreasing the residual water and increasing the mole ratio of n-butanol/lactic acid. Also, it was confirmed that methanol with simple structure and tert-butanol with superior substitution reactivity were more effective in increasing the conversion of esterification reaction, compared to ethanol, n-butanol, and iso-butanol. In a partial-recycling reactor (n-butanol/ammonium lactate = 4, $115^{\circ}C$), the conversion of ammonium lactate into butyl lactate with 1.0 wt% Amberyst-type resins was higher in comparison to that with 0.2 mol $H_2SO_4$ (per 1.0 mol ammonium lactate). The esterification was gradually occurred during the initial stage of reaction in the presence of solid catalyst, whereas the initial addition of $H_2SO_4$ did not affect the initial rate of esterification reaction because of ammonium sulfate formation by the neutralizing reaction of ammonium lactate with sulfuric acid.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.634-638
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• 1998

Monodisperse, spherical $PMSQ/TiO_2$ composite fine powders were prepared by modified sol-gel process where 300 nm $TiO_2$ fine powders were used as seed particles for hetero-condensation with hydrolyzed MTMS (Methyltrimethoxysilane). The reaction was carried out under $N_2$ atmosphere at ambient temperature using $NH_3$ as a catalyst. Methanol was used as a solvent. Powder was obtained by the filtration of the solution with a glass filter and washing with acetone. The stirring rate, reaction temperature, $[H_2O]/[MTMS]$ and $[MTMS]/[TiO_2]$ ratio were varied to investigate shapes and sizes of particles. Monodisperse particles of $1-2{\mu}m$ diameter were obtained with [MTMS]=0.2 M, $[NH_3]=0.6M$, $[H_2O]/[MTMS]=100$, $[MTMS]/[TiO_2]=10-50$ at ambient temperature with mild stirring condition. These composite particles had a contact angle of almost 180 degree contact angle with water, which proves their excellent hydrophobicity. The study of UV absorption spectra showed that they have UV protecting effect.

• Korean Journal of Food Science and Technology
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• v.50 no.1
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• pp.1-7
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• 2018

The MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay is commonly used for analyzing the cell viability. In this study, effects of various solvents, different lights, and zinc protoporphyrin (ZnPP) on the chemical behavior of MTT formazan were investigated. The color response of MTT formazan in NaOH was highly pronounced; the absorbance of MTT formazan in 0.1 N NaOH at 550 nm was >2-fold higher than that in water, dimethyl sulfoxide (DMSO), methanol, and ethanol. MTT formazan in DMSO and NaOH (>0.1 N) was relatively stable under fluorescent and UV light at 365 nm; its rapid degradation was induced under UV light at 254 nm in all solvents. ZnPP degraded MTT formazan under light in a time- and concentration-dependent manner; MTT formazan in 0.1 N NaOH was the most sensitive to ZnPP, followed by DMSO. These results suggest that NaOH and DMSO might be suitable media for MTT formazan for monitoring photosensitizing properties.

• Korean Journal of Food Science and Technology
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• v.50 no.1
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• pp.111-116
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• 2018

Roasting process of grains modifies their physicochemical characteristics that affect flavor, color, taste, and textures, as well as composition of bioactive compounds. We roasted oats at different temperatures (150, 200, and $250^{\circ}C$) and for different time periods (15 and 30 min). The polyphenol and flavonoid contents in different solvent extracts (methanol, fermented ethanol, and water) were also investigated. The total polyphenol and flavonoid contents were highest in the methanolic extract (135 mg gallic acid equivalent/g and 29 mg catechin equivalent/g, respectively, at $250^{\circ}C/30min$ roasting) and increased with roasting time and temperature. In addition, the avenanthramides were most abundant as accessed ($266{\mu}g/g$) in the methanolic extract upon roasting at $200^{\circ}C$ for 15 min. The radical scavenging activities, using 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid scavenging, increased with roasting temperature and time. The roasting process may modify the physicochemical structure of oats, thereby, improving polyphenol extraction and antioxidant activity. The results of this study could be used for the manufacture of foods using roasted oats.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.581-586
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• 1998

The present study was conducted to prepare seaweed extracts suppressing mutagenic activity of 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine ( PhIP ) ana 2-amino-3,8-dimethylmidazo[4,5-f]quinoxaline (MeIQx) derived from cooked meat produce. The tumor initiation activity of PhIP and MeIQx was assayed with Ames method using Salmonella typhimurium TA98 in the presence of S-9 mixtures before and after addition of methanol-solubles of seaweed, such as, Phaeophyta; Undaria pinnatifida, Ecklonia stolonifera Ecklonia cava, Laminaia japonica Sargassum fulvellum, Sargassum hornezi, Sargassum miyabei, Sargassum thunbergii, Agarum cribrosum and Hizikia fusifomis, Rhodophpei Porphyra yezoensis, Grateloupia eiliptiut Lomentraria catenata, Ploemium telfairiae and Glarilaria verrucosa, Chlorophyta; Codium fragile, Enteromorpha compresa and Ulva pertusa. Among seaweed tested, Phaeophyta was shown the higher desmutagenic activity than Rhodophyta and Chlorophyta. E. stolonifera, E. cava and S. miyabei, among Phaeophyta exerted the stronger desmutagenic activity (above $90\%$/2 mg). The ethyl acetate, diethyl ether and chlomform extracts except water extracts from E. stolonifera exhibited a high desmutagenic activity. The ethyl acetate extract of E. stolonifera which showed highest activity was fractionated with Sephadex LH20 column chromatography to give active fraction A-7, which showed desmutagenicity of $90\%$/mg against PhIP and $80\%$/mg against MeIQx. The active fraction had the absorbance at 207.7 and 232nm.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.587-593
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• 1998

To elucidate anti-tumor promoter from seaweed, the anti-tumor promoting activity of Ecklonia stolonifera, Undaria pinnatifida and Laminaria japonica extracts were determined by Epstein-Barr virus (EBV)-early antigen (EA) induction caused by a tumor promoter, teleocidin B-4. The methanol extracts of seaweed were subsequently fractionated with diethyl ether, distilled water, chloroform and ethyl acetate. Among the solvent fractions tested, chloroform and ethyl acetate fraction of E. stolonifera showed a high anti-tumor promoting activity at the levels of 88.0 and $85.9\%$ by the addition of 20 ${\mu}g/m{\ell}$, respectively. To characterize anti-tumor promoters from solvent fractions of E. stolonifera, the effects of phenols, chlorophyll derivatives and carotenoids on the anti-tumor promoting activity were investigated. Phenols, such as bromophenol and phloroglucinol showed anti-tumor promoting activity of $57\~66\%$ at 20 ${\mu}g/m{\ell}$. Pigments, such as chlorophylls and carotenoids exerted high anti-tumor promoting activities. Chlorophyll a and pheophorbide a exhibited the activity of $77.4\%$ and $66.6\%$ at 5${\mu}M/m{\ell}$, respectively. The active compounds of carotenoids were tentatively identified as lutein and $\alpha-cryptoxanthin$ from the profiles of visible spectra and R_f value of their authentic compounds, and showed anti-tumor promoting activities of $76.9\%$ and $84.4\%$ at dose of 20 ${\mu}g/m{\ell}$, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.943-948
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• 2001

Green mustard leves were found to effectively prevent lipid peroxidation of bovine-brain tissue by ascor-bate/Fe system, The 50% methanol extracts mustard leaves were separated into four solvent faction using n-hexane,. EtOAc, n-BiOH and water. Then n-BiOH fraction exclusively exhibited the antioxidative activities at concentration above 100 $\mu\textrm{g}$/mL/ The n-BuOH fraction was further isolated to a single compound using TLC analysis and silica gel chromatography. The active antiodidative compounds were identified as sinapic acid methyl ester and ferulic acid methyl ester by $^{1}$H-NMR and $^{13}$ C-NMR, The sinapic acid methyl ester and ferulic acid methyl ester were prepared by methylating of sinapic acid and ferulic acid with diazomethane. The results strongly suggested that sinapic acid and ferulic acid could be emplyed as a potential antioxiative agents for preventing the bovine brain lipid peroxidation. lipid peroxidation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.5
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• pp.769-777
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• 2004

A Helicobacter pylori urease inhibitor from Rubus coreanus Miquel has been isolated and partially characterized for aiming to Prevent H. pylori growth and decrease harmful accumulation of ammonia in human gastric mucosa. We screened urease inhibitory activities in 519 extracts library prepared by solvent extraction from 173 kinds of edible plants, medicinal herbs, herbs and seaweeds using a colorimetric urease assay system. As results of primary and secondary screening, 70% acetone extract of Rubus coreanus Miquel was selected as potent candidate, showing about 24% inhibitory activity. The acetone extract was sequentially partitioned into RCE/RCWI and RCB/RCW2 layers with ethyl acetate and butanol. The major active component in RCW2, water layer from butanol fractionation was revealed to be peptidic or proteinous substance by inhibitory activity determination after pronase digestion and periodate oxidation. RCW2-IIIc a was isolated by sequential column chromatography on DEAE-Toyopearl 650C, Butrl-Toyopearl 650M and Sephadex LH-20. The isolated urease inhibitor RCW2-IIIc $\alpha$, was highly pure proteinous substance with molecular weight of 13kDa by high-performance gel permeation liquid chromatography. RCW2-IIIc$\alpha$ has about 5 times higher inhibitory activity than 70％ acetone extract, showing high stability against heat treatment and peptic digestion.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.12
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• pp.1503-1510
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• 2007

This study was carried out to investigate antioxidant substances (phenolic compounds and brown pigment), antioxidative effect and nitrite scavenging ability (NSA) of solvent extracts (hexane: HE, methanol; ME, water: WE) from fermented soybean foods, Chungkukjang and Doenjang. The antioxidant activities were determined by the measurements of peroxide value (POV) on the linoleic acid system, electron donating ability (EDA) and superoxide dismutase (SOD)-like activity. The contents of phenolic compounds and total brown pigments in Doenjang were $28.5{\pm}0.3mg/100g$ and optical density (OD) $1.98{\pm}0.03$, respectively, whereas their contents in Chungkukjang were significantly lower with $5.8{\pm}0.3mg/100g$ and OD $0.95{\pm}0.02$. The brown pigment contents of hydrophilic extracts increased more than that of lipophilic extracts through the fermentation and ripening processes. The ME of Doenjang exhibited higher inhibitory effects against the peroxidation of a linoleic acid system than that of Chungkukjang. The EDA and NSA of MEs were higher than those of WEs. Among the MEs, Doenjang showed the highest levels of EDA and NSA. On the other hand, the SOD-like activities of WE were higher than those of ME at the same concentrations and their activities of Doenjang were significantly higher than that of Chungkukjang. In conclusion, the antioxidative effects and NSA of Doenjang was significantly higher than those of Chungkukjang. It seemed that phenolic compounds and brown pigments formed during fermentation and ripening partly affect the antioxidative activities of fermented soybean foods.