• Culinary science and hospitality research
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• v.24 no.2
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• pp.103-111
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• 2018

The objectives of the present study were to examine the antioxidant activity of autofocusing fractions from egg white protein hydrolysates and obtain higher antioxidant peptide fraction, which could be applied to the food model system. Alkaline protease hydrolysate of egg white protein exerted higher antioxidant activities than other protein hydrolysates and were fractionated on the basis of the amphoteric nature of sample peptides by preparative isoelectric focusing without toxic solvents and reagents, which is termed autofocusing. Neutral and basic fractions showed higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than the acidic fractions. The acidic and neutral fractions showed higher hydroxyl (OH) radical scavenging activity and oxygen radical absorbance capacity (ORAC) values than the basic fractions. The acidic fractions showed higher metal chelating activity than basic fractions. Antioxidant activities of some autofocusing fractions except for ORAC showed higher compared to the crude hydrolysate. These results suggest that peptides fractions from egg white protein are effective antioxidant, and that autofocusing could be useful to increase antioxidant activity for application to food system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.305-311
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• 1999

The volatile compounds of soybean pastes(home made soondoenjang, commercial doenjang) were classified into basic, acidic and neutral fractions by dynamic headspace method. The fractionated flavor isolates were analyzed and identified by gas chromatography mass spectrometry. Each peak area of the flavor components was quantified at its ratio to the peak area of internal standard. Sixty one compounds from home made soondoenjang, and forty three compounds from commercial doenjang were identified. The different distribution of volatile compounds between the two soybean paste samples was observed. Ten pyrazines and benzothiazole were identified in the basic fraction of home made soondoenjang. On the other hand, trimethylpyrazine was the only one of nitrogen containing compounds in the commercial doenjang, which was made from soybean(28.3%), wheat(22.2%) and alcohols. The factors which influenced the levels of these identified compounds were considered to be the starting materials of soybean paste. Alcohols, esters and aldehydes in the neutral fraction of both samples were seemed to be characterisitic soybean paste flavor and showed much higher quantities than those of the basic or acidic fractions. Furfural in the commercial doenjang was the highest content (45.28ppm) among all of the compounds identified in the samples.

• Applied Biological Chemistry
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• v.36 no.5
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• pp.370-375
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• 1993

Five electrophoretic bands of crude enzyme extracted from rice leaves were found to possess both chitinase and ${\beta}-1,3-glucanase$ activities. These $chitinase/{\beta}-1,3-glucanase$ were resolved into acidic and basic fractions of protein by DEAE-cellulose and chitin affinity column chromatography. The optimal pH and temperature for ${\beta}-1,3-glucanase$ activity of two fractions were in the same extent as pH 5 and $60^{\circ}C$, whereas those for chitinase activity differed from one another; pH 3 and $60^{\circ}C$ for the acidic and pH 4 and $50^{\circ}C$ for the basic fraction, respectively. In addition, lysozyme activity was found in both fractions.

• YAKHAK HOEJI
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• v.26 no.4
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• pp.223-229
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• 1982

Uremia is associated with defective protein binding of weakly acidic drugs, whereas the protein binding of basic drugs tends to be normal. The exact chemical nature of compound(s) and mechanism for these changes as yet is unknown, and has not been defined. Organic solvent extraction of pooled normal human urine following hydrolysis by hydrochloric acid produced an extract, which when added to normal human serum, was capable of inducing binding defects similar to those in uremia. Binding defects were observed with the weakly acidic drugs such as nafcillin, salicylate, sulfamethoxazole and phenytoin while the binding of the basic drugs such as trimethoprim and quinidine were unaffected. The binding defects induced by the hydrolyzed urine extract could readily be corrected by same organic solvent extraction of acidified serum and the defects could be transferred to the normal human serum using the organic solvent layer at the physiologic pH (7.4). Followed by reacidification ind extraction of the binding defects induced serum with the same solvent, separated several fractions were obtained on thin-layer chromatography. One of these fractions could reinduce the binding defects and this factor(s) is apparently weakly acidic compounds and tightly bound to serum at physiologic pH, but extractable at acidic pH, and its molecular weight range is approximately 500 or less similar to those seen in uremia. These findings strongly support the hypothesis that the drug binding defect in uremia is due to the accumulation of endogenous metabolic products which arc normally excreted by the kidneys but accumulate in renal failure.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.173-182
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• 1992

Regardless of the test species, germination was adversely affected by the different concentrations of the acidic and neutral fractions of sunflower root exudates while the basic and aqueous fractions had no effect on germination. In both test species, root lengths were inhibited slightly more than shoot lengths. Significant reduction in fresh weights of the test species was observed when the test species were treated with the acidic and neutral fractions but not with the basic and aqueous fractions. Six compounds, hydroquinone, ${\beta}$-resorcyclic acid, vanillic acid, caffeic acid, salicylic acid, and quercetin, were characterized from the acidic fraction. Seven compounds, hydroquinone, gentisic acid, ${\beta}$-resorcyclic acid, vanillic acid, caffeic acid, ferulic acid, and quercetin, were elucidated from the neutral fraction.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.761-769
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• 1995

About 2.1g of pale yellow flavor concentrate was obtained from 10kg of chopped fresh ascidians through a Likens-Nickerson steam distilllation/solvent extraction. These concentrates could be fractionated to neutral $(91.5\%),\;basic\;(1.0\%),\;phenolic\;(3.2\%),\;and\;acidic\;(4.3\%)$ fractions. Total 65 volatile compounds were identified from those concentrates. The neutral fraction was representative flavor fraction which showed a similar flavor of total steam distillates of ascidian. The major compounds $(38.2\%\;of\;neutral\;fraction)$ were identified as carbon atoms 8 to 10 of alcohols. Among these volatile alcohols, 1-octanol, 2,7-decadien-1-o1, 3-octen-l-01, 7-decen-l-ol, and l-decanol were the dominent compounds found in neutral fraction. But the basic, phenolic, and acidic fractions differs from ascidian steam distillates flavor.

• Applied Biological Chemistry
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• v.38 no.4
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• pp.289-292
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• 1995

Fig leaves were extracted with methanol and then fractionated with ethyl acetate and various buffers to get active fractions, and their antimicrobial activities in each fraction were determined. Acidic fraction and phenolic fraction of fig leaves showed strong antimicrobial activities, but the basic fraction and neutral fraction did not show any activities. The degree of antimicrobial activities in phenolic fraction against tested bacteria were higher than those in acidic fraction, but these against yeasts and mold were almost equivalent to those in acidic fraction. Especially, phenolic fraction showed the strongest activities against Staphylococcuns aureus and Pseudomonas aeruginosa. Although there were some differences among microorganisms, minimum inhibition concentrations(MIC) in acidic and phenolic fractions against tested microorganisms were 0.05 to 0.1 g eq./ml and 0.01 to 0.25 g eq./ml, on the basis of fresh sample weight, respectively. Minimum lethal concentrations(MLC) in acidic and phenolic fractions were 0.25 to 2.00 g eq./ml and 0.05 to 1.50 g eq./ml, respectively. These supposed the antimicrobial activities in phenolic fraction were generally higher than those in acidic fraction and also phenolic fraction had lower MIC and MLC values than acidic fraction.

• BMB Reports
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• v.34 no.4
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• pp.310-315
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• 2001

The uneven distribution of acidic and basic chitinases in different parts of rice seed, and also the characterization of hull-specific chitinases, are reported here. After extraction of chitinases from polished rice, bran, and rice hulls, the chitinases were separated into acidic and basic fractions, according to their behavior on an anion exchanger column. Both fractions from different parts of rice seed showed characteristic activity bands on SDS-PAGE that contained 0.01% glycol chitin. The basic chitinases from rice hulls were further purified using chitin affinity chromatography. The chitinase, specific to rice hulls (RHBC), was 88-fold purified with a 1.3% yield. RHBC has an apparent molecular weight of 22.2 kDa on SDS-PAGE. The optimal pH and temperature were 4.0 and $35^{\circ}C$, respectively. With [$^3H$]chitin as a substrate, RHBC has $V_{max}$ of 13.51 mg/mg protein/hr and $K_m$ of 1.36 mg/ml. This enzyme was an endochitinase devoid of ${\beta}$-1,3-glucanase, lysozyme, and chitosanase activities.

• YAKHAK HOEJI
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• v.33 no.1
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• pp.46-53
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• 1989

The extractable organic matter was extraced from airborne particulates collected in Seoul during 1986. It was fractionated to several fracrtions and mutagenicities of them were tested in Salmonella thyphimurium TA98 by Ames method. The neutral fraction showed the highest indirect acting mutagenicity while the highest direct acting mutagenicity was observed in the acidic fraction. Indirect acting mutagenicity of airborne particulate was attributed to its neutral fraction about 88% in average, to acidic about 10% in average and to basic fraction about 2% in average. Direct acting mutagenicity of airborne particulate was attributed to its neutral fraction about 70%, to acidic fraction about 29% and to basic fraction about 1%. Among five subfractions of neutral fraction, the proportion of mutagenicity of polynuclear aromatic hydrocarbon subfraction was 13.2% in indirect acting mutagenicity and 5.0% in direct acting mutagenicity.

• Applied Biological Chemistry
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• v.38 no.4
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• pp.293-296
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• 1995

Fig leaves were extracted with methanol and then fractionated with ethyl acetate and various buffers to get active fractions and determined the antimicrobial activities. The acidic and phenolic fractions fractionated from the methanol extract of fig leaves showed the strong antimicrobial activities, but the basic and neutral fractions did not show any activities. The degree of antimicrobial activities of phenolic fraction against tested bacteria was higher than those of acidic fraction, but these against yeasts and mold were almost equivalent to those of acidic fraction. Especially, phenolic fraction was mostly affected on Staphylococcus aureus and Pseudomonas aeruginosa. Four antimicrobial substances purified from the phenolic fraction which showed the strongest antimicrobial activities among the fractions from fig leaves, were identified as psoralen($C_{11}H_{6}O_{3}$, MW. 186), bergapten($C_{12}H_{8}O_{4}$, MW. 216), ${\beta}$-sitosterol($C_{29}H_{50}O$, MW. 414) and umbelliferone ($C_{9}H_{6}O_{3}$, MW. 162).