• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.1
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• pp.7-11
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• 1988

This study was carried out in order to analyse the amino acid constituents of Gynostemma pentaphyllum Makino (G. P. M. ) produced in Korea and Japan. Total and free amino acids of those were analysed by HPLC. Total amino acid contents of G. P. M. produced in Korea were similar to that of produced in Japan. The Histidine content of G. P. M. produced in Korea was more rich than that of produced in Japan. The content of glutamic acid was the most rich among in kinds of amino acids in both hind of G. P. M. G. P. M. in Korea contained the least methionine and G. P. M. from Japan contained the least cystine.

• Journal of the Korean Chemical Society
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• v.15 no.5
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• pp.275-280
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• 1971

Six previously unreported N-acylated-DL-1-amino alkyl phosphonic acids were prepared; N-Acetyl-DL-1-amino-3-methyl butyl phosphonic acidN-Benzoyl-DL-1-amino-2-methyl propyl phosphonic acidN-Benzoyl-DL-1-amino-3-methyl butyl phosphonic acidN-Benzoyl-DL-1-amino-2-methyl butyl phosphonic acidN-Acetyl-DL-1-amino-2-methyl propyl phosphonic acidN-Acetyl-DL-1-amino-2-methyl butyl phosphonic acidThe first four compounds were characterized, and the last two compounds were obtained in the crude oil state. The above three DL-1-amino-alkyl phosphonic acid were synthesized from iso-valeric acid, iso-caproic acid and ${\beta}$-methyl valeric acid using Hell-Volhard-Zelinsky reaction, the condensation reaction with triethyl-phosphite and the modified Curtius Reaction. Iso-caproic acid and ${\beta$-methyl valeric acid were prepared by the conventional methods.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.122.1-122.1
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• 2011

The motivation for this work was the potential of hydrophobic amino acids such as glycine, L-alanine, and L-valine to be applied as thermodynamic hydrate inhibitors (THIs). To confirm their capabilities in inhibiting the formation of gas hydrates, three-phase (liquid-hydrate-vapor) equilibrium conditions for carbon dioxide hydrate formation in the presence of 0.1 to 3.0 mol% amino acid solutions were determined in the range of 273.05 to 281.45 K and 14.1 to 35.2 bar. From quantitative analyses, the inhibiting effects of the amino acids (on a mole concentration basis) decreased in the following order: L-valine > L-alanine > glycine. The application of amino acids as THIs has several potential advantages over conventional methods. First, the environmentally friendly nature of amino acids as compared to conventional inhibitors means that damage to ecological systems and the environment could be minimized. Second, the loss of amino acids in recovery process would be considerably reduced because amino acids are non-volatile. Third, amino acids have great potential as a model system in which to investigate the inhibition mechanism on the molecular level, since the structure and chemical properties of amino acids are well understood.

• Bulletin of the Korean Chemical Society
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• v.11 no.5
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• pp.411-415
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• 1990

The dabsylation of amino acids has been applied to resolve their optical isomers with the use of chiral mobile phase in high performance liquid chromatography. The dabsyl amino acids were successfully separated on reversed phase column($C_{18}$) by adding a chiral L-benzylproline-Cu(II) chelate to the mobile phase. The separation selectivity of the dabsyl amino acid enantiomers was not less than that of dansyl amino acids. The retention order of the dabsyl amino acid enantiomers was as those of the dansyl amino acid enantiomers except dabsyl threonine. The optical selectivity of the dabsyl amino acids increase with pH of the mobile phase and concentration of the chelate, but slightly decreases with concentration of buffer and organic solvent composition. However serine, methionine, valine, and leucine showed a slight decrease in the optical selectivity with increase in pH. The retention times of the dabsyl amino acids decreases with increasing pH and acetonitrile concentration but increases with the concentration of the chiral chelate added. The mechanism of the optical resolution is based on a stereospecific interaction including a intramolecular hydrophobic effect and SN-2 reactivity of the ligand exchange chromatography.It is advantageous to detect absorption at 436 nm, which is less interferent them the other detection systems. The derivatized dabsyl amino acids are stable for a month.

• The Korean Journal of Mycology
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• v.11 no.2
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• pp.85-89
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• 1983

The aims of this study were to investigate various components and their physiological activities of Sarcodon aspratus (Berk.) S. Ito which grows wildly in Korea, belonging to the family Thelephoraceae. The analysis of the powered carpophore of this fungus by TLC and an amino acid autoanalyzer revealed that it contained twenty-one free amino acids and that twenty­two total amino acids were identified in its acid hydrolysate. These amino acids were also quantified.

• Journal of the Korean Home Economics Association
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• v.19 no.1
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• pp.25-31
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• 1981

The changes of various nitrogenfractions and free amino acid composition were investigated at various growing stages. The results are summarized as follows 1) Total nitrogen, water soluble protein nitrogen, and true protein nitrogen were decreased with growth. 2) Free amino acid increased with sprout-growth. the content of free amino acid were about 74.4%(combined Ser, Asp, Arg, Val) after 4 day sprout. It is belived that serine, aspartic acid, arginine and valine play an important role as taste compounds in mungbean sprout. 3) 16kinds of amino acid, including essential amino acids in human nutrition except tryptophan and cystin were quantified.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.3
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• pp.211-218
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• 1991

The effects of dietary fiber on true digestibility of amino acids by growing pigs were studied, using semi-purified diets formulated from alfalfa meal, cassava leaf meal, rubber seed meal and leucacna meal at 20% level. A protein-free diet including 5% cellulose was formulated for correcting the endogenous amino acid loss. Across all the diets, arginine was the most digestible while the least at ileal level was threonine; methionine and/or histidine at fecal level respectively. The true digestibility value of amino acids at ileal level were higher than at fecal level except control diet (cellulose). The true digestibility values at ileal level were similar for all diets but differed at fecal level in different magnitude. These results indicate that undigestible compound in individual feedstuff might confound. True digestibility should be studied together for accurate diet formulation as apparent digestibility decreased when their amino acid concentration in the diet was reduced.

• Journal of environmental and Sanitary engineering
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• v.2 no.3 s.3
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• pp.13-22
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• 1987

For the amino-N -ratio and N- solubity, irradiated samples were higher than non - irradiated them, that is, 15KGy(l9, 72), 7KGy(l9, 55) of amino-N-ratio were more those of 5KGy(17. 91) and l0KGy(l8, 06). during the fermentation of samples. For the Solubility of nitrogen, irradiated samples were decreased sequencely, such as 10KGy, 7KGy, 15KGy and 5KGy. For the amounts of amino acid, Content of the glutamic acid was the highest in the all samples and the main free amino acids in the Steamed Soybeans Were glutamic acid, proline, arginine, and alanine etc. However the amount of amino acid in the irradiated Sample was notably increased in Comparison with the nonirradiated $(10.8017\%)$ and 7KGy amino acid $(15.4166\%)$ was highest.

• Journal of Integrative Natural Science
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• v.8 no.2
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• pp.111-116
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• 2015

Liquid chromatographic enantiomer separation of ${\alpha}$-amino acid esters as nitrobenzoxadiazole (NBD) derivatives was performed using several chiral stationary phases (CSPs) based on polysaccharide derivatives under fluorescence detection. For enantiomer separation by normal HPLC, the non-aqueous derivatization method of ${\alpha}$-amino acid esters for NBD analytes was introduced. Among the six CSPs used in this study, the performance of Chiralpak IA was superior for enantiomer resolution of NBD derivatives of several ${\alpha}$-amino acid methyl esters. Also the convenient analytical method using polysaccharide-derived CSPs developed in this study was applied to determine the optical purity of ${\alpha}$-amino acids esters. It was investigated that the enantiomeric impurity levels of 0.02-1.73% were found after determination of enantiomeric purities of several commercially available L-amino acid methyl esters. It is expected to be quite useful for enantiomer separation of other ${\alpha}$-amino acid esters as NBD derivatives by normal HPLC.

• The Korean Journal of Food And Nutrition
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• v.12 no.5
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• pp.496-501
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• 1999

Albinism is a phenomenon that color of the body surface is changed to white orfaint brown from the specific color to the species by difficiency of pigments due to mutation or disease. This study was undertaken to investigate the experimental basis on the appearance of albinism in cultured flounder Paralichthys olivaceus. The skin and muscle from the normal and albinic flounder were used by measuring contents of amino acid free amino acid. The results were summarized as follows: Contents of amino acid in theskin and muscle are different from normal and albinic flounder. Phenolic and sulfuric amino acids in the skin of normal flounder were 2 times those of albinic ones. Especially tyrosine contents of the skin in normal flounder were 24 times higher than those. Methionine was 26 times higher than those Phenylalanine was 1.6 times higher. In free amino aicd phosphoserine and phosphoethanolamine were a little higher than that ones. The melanin formation of the skin in flounder was affected by substrates such as phenolic amino acid and cofactor such as sulfuric amino acid.