• Journal of Applied Biological Chemistry
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• v.55 no.3
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• pp.149-156
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• 2012

The effects of solvent type and concentration, solid/liquid ratio, extraction time and repeated extraction on recovery of keratinase from solid-state fermentation (SSF) of chicken feather by a local Streptomyces sp. NRC 13S were investigated in order to establish the experimental conditions for keratinase yield. Among solvents tested, 0.5% (v/v) glycerol was the best. Box-Behnken design was used to investigate the effect of relevant variables on keratinase recovery. The factors investigated were solid/liquid ratio (1:1.66-1:6.66 g/mL), glycerol concentration (0.5-5% v/v) and repeated extraction (1-5 cycle). The results showed that the maximum recovery of keratinase (6933.3 U/gfs) was obtained using 0.5 (v/v) glycerol as extracting solvent, in a solid/liquid ratio of 1:5 and three extraction cycles.

• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1403-1408
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• 2014

The cycloaddition reactions of the N-heterocyclic carbene boryl azide with methyl acrylate, butenone, and hexafluoropropene have been investigated theoretically. Solvent effects on these reactions have been explored by calculation that included a polarizable continuum model (PCM) for the solvent (C6H6). The title reaction could produce 4- and 5-substituted 1,2,3-triazolines, respectively. The reaction systems have the higher chemical reactivity with the low barriers and could be favored. Yet the smaller differences have been found to occur in energetics, and the cycloaddition reactions occur for s-trans conformations over s-cis conformations. The calculations indicated that the cycloaddition reaction of the alkenes have certain regioselectivity.

• Journal of the Korean Dietetic Association
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• v.4 no.1
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• pp.14-19
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• 1998

This study was designed to investigate the role of onion as a natural antioxidant. Onion was distinguished as yellow onion peel and onion flesh. Onion samples were extracted with 5 different kinds of solvents such as water, 70% ethanol, 99.9%ethanol, 99.9% methanol, and 96% butanol in order to select optimal extraction solvents, In this part of study linoleic acid was used s an model system for the purpose of determining the antioxidant activities. The optimal extraction rate of various solvents containing onion samples was determined by measuring extraction yield, electron donating ability(EDA), thiobarbituric acid(TBA), and thiocyanate, which are common methods for measuring activity. As a result 70% ethanol was shown as the most effective solvent.

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.459-465
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• 2016

This study investigated reusability of costly guard column by ultrasonic. It also investigated various effects that affect to guard column generation by ultrasonic. When investigated 30 KHz of frequency, area of ascorbic acid is 73.0% compared to unused guard column. As a result of investigation of effect of pH, guard column by ultrasonic is effective at alkali area. As a result of investigation of solvent effect, when ethanol is used, generation rate is 81.9% as of peak area compared to the case of analysis in un used column. From the result, it indicates that regenerated guard by ultrasonic is reusable.

• The Korea Journal of Herbology
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• v.22 no.4
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• pp.29-34
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• 2007

Objective : Kyenegum(Galli Stomachichum Corium) has been popularly used long as the digestive. The purpose of this study was to investigate the enzymatic characteristic of Kyenegum crude enzyme. Methods : To evaluate of the enzymatic characteristic of Kyenegum, we examined the activity of Kyenegum crude enzyme from optimum solvent, optimum temperature and pH of crude Kyenegum extract. Futhermore, we examined the effects of NaCI and acidity of crude Kyenegum extract. Results : The Kyenegum was composed with crude protein about 20%, crude lipid 2%. The optimum Kyenegum dry condition, optimum extract solvent, optimum temperature and optimum pH were $4{\sim}6$ hours at $60^{\circ}C$, commercial apple vinegar, $50^{\circ}C$ and 2.0. Conclusion : The result suggests that the Kyenegum crude enzyme extract very strong enzyme in temperature, NaCl and acidity, respectively.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.1
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• pp.179-183
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• 2005

Recent interest in the possible protective effects of dietary antioxidant compounds against human degenerative disease has prompted investigation of foods such as blueberries, which have a high antioxidant capacity. This study was performed to determine the antioxidative activity of methanol extract and solvent fractions from blueberry. Blueberry was extracted with methanol and then fractionated with n-hexane, EtOAc, BuOH and water to get active fractions. And their antioxidant capacities in each fraction were determined by using the DPPH and FRAP assay, and tyrosinase inhibitor. Ethyl acetate fraction of blueberry exhibited antioxidant capacity.

• Natural Product Sciences
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• v.19 no.2
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• pp.166-172
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• 2013

Caffeine and epigallocatechin gallate (EGCG) are major constituents of green tea, the leaves of Camellia sinensis (Theaceae). Although EGCG is well known for diverse beneficial effect, caffeine is sometimes harmful with adverse effects. Therefore, the extraction efficiency was investigated using different extraction method such as extraction solvent, extraction time, extraction method, and repeated extraction. The content of EGCG and caffeine in green tea extract was quantitated by HPLC analysis. The extraction condition exerted difference on the extraction yield. The content of EGCG was also affected by different extraction condition. Especially, the extraction solvent greatly affected the content of EGCG in the extract. However, the content of caffeine was less affected compared to that of EGCG. The inhibitory effect of green tea extract on pancreatic lipase was almost similar regardless of extraction condition. Taken together, optimization of extraction condition will provide best efficacy for further development of green tea as anti-obesity therapeutics.

• The Korean Journal of Food And Nutrition
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• v.11 no.4
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• pp.426-430
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• 1998

This study was conducted to investigate electron donating ability, antioxdative activity and nitrite-scavenging effect of solvent extracts from Gyrophora esculenta. The phenolic compounds of diethylether, butanol, petroleum ether and hexane extracts were 194.20$\mu\textrm{g}$/ml, 98.80$\mu\textrm{g}$/ml, 1.60$\mu\textrm{g}$/ml and 0.20$\mu\textrm{g}$/ml, respectively. Electron donating abilities of diethyleter and butanol extracts from Gyrophora esculaenta were 80.79% and 72.81%, respectively. Absorption of DPPH by diethyleter and butanol extracts sharply increaed at initial stage. Antioxidative activities of fiethylether and butanol extracts by peroxide values are rather high as compared to those of control, but low s compared to those of BHA. Nitrite-scavenging abilities of diethylether, butanol and petroleum ether from Gyrophora esculenta were 96.07%, 77.39% and 15.07%, respectively.

• Korean Journal of Pharmacognosy
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• v.12 no.1
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• pp.51-54
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• 1981

Twenty-seven medicinal plants were selected on the basis of folkloric reputation for the treatment of hypertension or related deseases. Two solvent fractions were prepared from methanol extract of each plant and tested for their effects on angiotensin converting enzyme (ACE) activities. Six solvent fractions showed more than 50% inhibition and four showed $40{\sim}50%$ inhibition at the conditions tested.

• Proceedings of the KIEE Conference
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• 2007.11c
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• pp.138-140
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• 2007

$TiO_2-V_2O_5$ sol was fabricated using sol-gel method and $TiO_2-V_2O_5$ thin films were fabricated using dip-coating method. $V_2O_5$ sol was added 0.01mo1e, 0.03mo1e, 0.05mo1e into $TiO_2$ sol. Viscosity of sol increased fast from about 1,000 minutes and sol began gelation from about 10,000 minutes. As a results of crystalline properties, $V_2O_5$ peaks were not found despite of $V_2O_5$ addition. Endothermic reaction occurred due to evaporation of solvent and dissociation of OH at $80^{\circ}C$. Exothermic reaction occurred due to combustion and oxidation of solvent at $230^{\circ}C$, occurred to combustion and oxidation of alkyl group at $350^{\circ}C$. Thickness of thin films increased $0.1{\sim}0.25{\mu}m$ every a dipping.