• Korean Journal of Soil Science and Fertilizer
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• v.25 no.4
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• pp.407-410
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• 1992

Changes in the concentrations of six low-molecular-weight organic acids extracted from hydrolysates of plant residues undergoing decomposition for 90 days under the laboratory condition were investigated. 1. Litters of deciduous and coniferous trees and wild grass cuttings were sampled for the study and concentrations of formic, acetic, succinic, tartaric, malic and citric acids were determined. The concentration of malic acid were negligible. 2. In the wild grass cuttings, the total concentration of low-molecular-weight organic acids decreased with the passage of decomposition. Monocarboxylic acids, I. e., formic and acetic acids, predominated over dicarboxylic and tricarboxylic acids. Formic and acetic acids appeared to be compensatory for each other. Concentration of citric acid increased at a remarkable rate. 3. The total concentration of organic acids in the hydrolysates of deciduous litter was shown to increase. The concentration of monocarboxylic acids was significantly higher in the end of the period of decomposition. Here again a compensatory relationship was observed between concentrations of formic and acetic acids. 4. There was comparatively little change exhibited during the period of experiment concerning the concentrations of organic acids from hydrolysates of decomposing coniferous litter. In contrast with the others, however, the concentration of succinic acid, a dicarboxylic acid, maintained the highest level.

• Korean Journal of Microbiology
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• v.38 no.2
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• pp.144-151
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• 2002

For elucidating the relationship between the biosynthetic pathways for polyhydroxyslkanoates (PHAs) and 5-aminolevulinic acid (ALA), culture conditions for the production of these two biomaterials by Rhodopseudomonas sp. KCTC 1437 were investigated. Of the carbon substrates tested, acetic acid was the best carbon source for cell growth and PHA biosynthesis. When succinic acid was added as a co-substrate into culture medium, cell growth and PHA production were greatly increased up to 2.5 g/ι and 73% of dry cell weight, respectively. The PHA obtained from the carbon substrates tested was homopolyester of 3-hydroxybutyrate, while valeric acid was only effective for the production of copolyester consisting of 3-hydroxybutyrate and 3-hydroxyvalerate. Anaerobic light culture condition was better for PHA production and cell growth than anaerobic dark or aerobic dark culture condition. The organism was capable of synthesizing ALA when glycine and succinic acid were added to the culture medium. ALA was produced to ca.400 mg/ι when levulinic acid, soccinic acid, and glycine were repeatedly added with a reductant (sodim thioglycolate). However, the presence of glycine, levulinic acid and sodium glycolate inhibited the cell growth and the conversion of carbon substrates to PHA. From these results it is apparent that the production yields of PHA and ALA could not be increased simultaneously because the optimal conditions for the production of PHA and ALA are opposed to each other.

• Molecules and Cells
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• v.37 no.10
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• pp.719-726
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• 2014

The ${\gamma}$-Aminobutyric acid (GABA) that is found in prokaryotic and eukaryotic organisms has been used in various ways as a signaling molecule or a significant component generating metabolic energy under conditions of nutrient limitation or stress, through GABA catabolism. Succinic semialdehyde dehydrogenase (SSADH) catalyzes the oxidation of succinic semialdehyde to succinic acid in the final step of GABA catabolism. Here, we report the catalytic properties and two crystal structures of SSADH from Streptococcus pyogenes (SpSSADH) regarding its cofactor preference. Kinetic analysis showed that SpSSADH prefers $NADP^+$ over $NAD^+$ as a hydride acceptor. Moreover, the structures of SpSSADH were determined in an apo-form and in a binary complex with $NADP^+$ at $1.6{\AA}$ and $2.1{\AA}$ resolutions, respectively. Both structures of SpSSADH showed dimeric conformation, containing a single cysteine residue in the catalytic loop of each subunit. Further structural analysis and sequence comparison of SpSSADH with other SSADHs revealed that Ser158 and Tyr188 in SpSSADH participate in the stabilization of the 2'-phosphate group of adenine-side ribose in $NADP^+$. Our results provide structural insights into the cofactor preference of SpSSADH as the gram-positive bacterial SSADH.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1091-1097
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• 2002

In order to improve palatability and quality of traditional kochujang, kiwifruit (Actinidia deliciosa) was added to traditional kochujang fermented for 3 months. Physicochemical and microbial characteristics were investigated during fermentation at $30^{\circ}C$. Moisture contents of all treated kochujangs increased with increasing amount of kiwifruit added during fermentation. pH of kiwifruit-added kochujang was lower than that of the control kochujang, whereas no significant differences in titratible acidity was observed among all treatments. Crude protein and salt contents of kiwifruit-added kochujang were lower than those of the control, whereas no difference in crude fat contents were found. Ethanol and amino-nitrogen contents of 6 and 9% kiwifruit-added kochujang were higher than those of the control. Fructose contents of kiwi-added kochujangs were higher than that of the control. Major organic acids of kochujang were in the order of malic acid > citric acid > succinic acid > acetic acid > lactic acid > oxalic acid. Succinic acid level increased significantly during fermentation and was higher in kiwifruit-added kochujang than in the control. Bacterial cell counts of all treatments were not different, and viable cell count of yeast was slightly higher in kiwifruit-added kochujang only at the initial fermentation period. Sensory evaluation revealed that the addition of 9% kiwifruit was the optimum condition for improving kochujang quality.

• YAKHAK HOEJI
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• v.34 no.2
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• pp.133-138
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• 1990

The reaction of 2-aminobenzamide with phthalic acid anhydride In dioxane produced a bicyclic product 2,8-dioxoisoindole(1,2,a) quinazoline (I) in addition to hydrolysis product 2(2-Carboxyphenyl)-1,2-2H-quinazoline-4-one (II). The yields were 64% and 30% respectively. On the other hand, the same reaction in DMF afforded compound (I) and 2(2N-dimethyl carbamyl phenyl)-1,4-2H-quinazoline-4-one (III) in 30% and 60% yield respectively. The compound III was also obtained by the reaction of compound II with dimethylamine. However the reaction of 2-aminobenzamide with neat succinic acid anhydride gave only bicyclic product 2,8-oxopyrrolidine (2,1,a)-1,4-2H-quinazoline (IV) in 93%.

• Food Science and Preservation
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• v.20 no.3
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• pp.330-335
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• 2013

This study was conducted to investigate the food value of Cudrania tricuspidata at its various maturation stages. The pH, total acid and reducing sugar contents of its fruit juice were determined to have been 4.2~5.1, 1.4~2.0% and 5.4~8.6%, respectively. The general chemical components of its fruit were observed as 76~80% moisture, 2.2~3.5% crude protein, 1.7~2.9% crude fat, 0.8~1.2% ash and 14.5~16.4% carbohydrate. Its free sugar, glucose and fructose contents were determined. The fructose contents of both its ripened and over-ripened fruits were higher than their glucose contents. Organic acids such as oxalic acid, citric acid, tartaric acid, malic acid and succinic acid were detected, and the concentration of the malic acid and the succinic acid were found to have been most abundant. The K content was higher than the amounts of other minerals, such as Ca, Fe, K, Mg, Na and P. Its vitamin C and the total amount of its dietary fiber were 127.5~149.2 mg% and 22.7~38.7%, respectively. Its insoluble dietary fiber content was higher than its soluble dietary fiber content. Its total polyphenol and flavonoid content were 18.9~19.6 mg% and 40.9~48.2 mg%, respectively.

• Korean journal of food and cookery science
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• v.19 no.1
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• pp.1-10
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• 2003

All optional ingredient, Jasoja(Perillae semen) was adopted to improve Dongchimi in qualify during fermentation. Free sugar, free amino acid, non-volatile organic acid and volatile compounds were determined during fermentation at 10$^{\circ}C$ for 45 days. Free sugar content was slightly higher in 0.5%-Jasoja-treated samples than that of control. The contents of free amino acids in control Dongchimi (without jasoja) increased slowly during fermentation while those in 0.5 %-treated samples began to decrease after reaching their maximum value on the day 11 when Dongchimi became most acceptable. There were 6 non-volatile organic acids, such as lactic, fumaric, succinic, malic, tartaric, and citric acid. Among these, only lactic and succinic acid increased consistently with fermentation while others decreased. Volatile components in Dongchimi were mostly identified as sulfur-containing compounds by gas chromatography. Their numbers and % peak areas in the gas chromatogram decreased slightly with the increase in organic acids and alcohols during fermentation period. On the other hand, Dongchimi prepared with Jasoja maintained its contents of total acids as well as the level of sulfur-containing compounds.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.777-781
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• 2001

The effects of gamma-irradiation on the nutritional components of some Korean soybean-based fermentation foods were studied. Doenjang (soybean paste), kochujang (red pepper paste) and chungkukjang were prepared, irradiated at 0, 5, 10 and 20 kGy, and their compositions of free amino acid, free fatty acid and organic acid were determined. Compositions of free amino acid and free fatty acid in gamma irradiated sample were stable compared to non-irradiated control. Content of citric acid and succinic acid increased, while that of malic acid decreased in the gamma irradiated chungkookjang, but there were no significant changes in organic acid composition in organic and kochujang.

• Microbiology and Biotechnology Letters
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• v.13 no.3
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• pp.285-287
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• 1985

To investigate effective constituents of the many taste components in ordinary Korean soy sauce, we analyzed free amino acids, organic acids, free sugars and saline as taste components in ordinary Korean soy sauce, and determined sensory score of the ordinary Korean soy sauce taste with 45 persons of the trained pannels. The relationships between original data transformed with variables and sensory score of the ordinary Korean soy sauce were analyzed by stepwise multiple regression analysis. Eighty five percents of the ordinary Korean soy sauce taste is affected by twenty one kinds (Isoleucine, Leucine, Valine, NaCl, Lactic acid, Alanine, Phenylalanine, Tartaric acid, Sugar(\ulcorner), Proline, Malic acid, Glycine, Tryptophan, Arginine, Glutaric acid, Maltose, Histidine, Glucose, Fructose and Serine) of the taste components by stepwise multiple regression analysis of original data. Eighty one percents of the ordinary Korean soy sance taste is affected by sixteen kinds (Lactic acid, NaCl, Fumaric.Succinic acid, Tyrosine, Tartaric acid, Glycine, Malonic acid, Malic acid, Tryptophan, Glutaric acid, Methionine, Histidine, Cysteine, Maltose, Fructose and (Glutamic acid) of the taste components by stepwise multiple frgression analysis of original data transformed with square root. Eighty five percents of the ordinary Korean soy sauce taste is affected by nineteen kinds (Fumaric.Succinic acid, Lactic acid, Phenylalanine, NaCl, Tyrosine, Sugar(\ulcorner), Tartaric acid, Leucine, Glutaric acid, Methionine, Glycine, Tryptophan, Histidine, Proline, Cysteine, Glutamic acid, Maltose, Threonine and Oxalic acid) of the taste components by stepwise multiple regression analysis of original data transformed with logarithm.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.316-325
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• 2018

Aluminum based metal-organic framework using a di-carboxylate linker succinic acid (Al-SA MOF), are synthesized in water with minimal generation of secondary pollutants. The physicochemical properties of Al-SA MOF were examined, followed by its utility for the adsorption of Acid Black 1 (AB1) in aqueous media. Influences of key parameters such as pH, contact time, initial AB1 concentration,temperature, and selectivity on the adsorption process were assessed. A series of adsorption mechanisms are proposed, which involve electrostatic, hydrogen bonding, and hydrophobic interactions. These findings suggest that Al-SA MOF is a potent candidate in removing complex azo dyes molecules from aqueous media.