• Macromolecular Research
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• v.13 no.1
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• pp.39-44
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• 2005

Ion-exchange polymeric stationary phases presenting amino acid and amino groups were prepared by the surface grafting of glycidyl methacrylate onto a silica gel surface and subsequent amination. Three kinds of amino acids-L-arginine (Arg), D-lysine (Lys), and D-histine (His)-were used in this study. An ion-exchange polymeric stationary phase presenting ethylene diamine (EDA) was also prepared by surface graft polymerization. Separation of the model proteins bovine serum albumin (BSA), chick egg albumin (CEA), and hemoglobin (Hb) was performed using the amino acid- and amine-derived columns. In separating the CEA/BSA mixture, the resolution time of BSA was longer than that of CEA when using the EDA column, whereas the resolution time of BSA was shorter than that of CEA when using the Arg, Lys, and His columns. In the separation of the Hb/BSA mixture, the resolution time of BSA was longer than that of Hb in the EDA column, whereas the resolution time of BSA was shorter than that of Hb in the amino acid columns (D-Lys, L-Arg, and D-His).

• Korean Journal of Food Science and Technology
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• v.22 no.1
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• pp.88-93
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• 1990

For effective separation of the N-TFA n-butyl ester amino acids on the stainless steel column by GLC, dual column of the mixed stationary phases, 3.36% OV-17+3.0% SE-30(column 1) and 1% NPGS +0.5% OV-17+0.5% SE-30(column 2) on chromosorb W HP 100-120 mesh, were used. On the column 1. the nineteen amino acids except histidine were obtained. However, alanine and valine peaks were not separated by this column. On the column 2, the sixteen amino acid peaks showed good separation, but tryptophan. arginine, histidine, and tyrosine peaks were not obtained. Calibration graphs for all amino acids obtained by the plotting the ratios of their peaks hights to that of internal standard versus the micro mole of the amino acids in the range $1.25{\times}10^{-3}{\mu}mol-1.0{\times}10^{-2}{\mu}mole$ showed linearity and passed through the origin.

• YAKHAK HOEJI
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• v.28 no.1
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• pp.21-23
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• 1984

High performance amino acid analyzing method has been developed for the routine analysis of taurine in preparations. Ion-exchange resin #2619 Hitachi Custom Ion-Exchange Resin, $2.6(I.D.){\times}150$(length)mm was used as column, buffer I, pH 3.3 as mobile phase. The retention time of taurine was 7 minutes. Calibration curve by peak height for standard taurine was linear from 2.5ppm to 25ppm. The reproducibility showed relative standard deviation $\pm$1.9% when analyzed 10 times for standard solution. The samples could be continuously analyzed without regenerating the resin between samples. Five samples were applied to column every 12 min. and then the resin was regenerated for 30 min. during one analyzing cycle time, 90 min. The automatic amino acid analyzer has made it possible to assay multiple samples in a relatively short period of time using the analytical magnetic program card. The high sensitivity and specificity of the analytical column of the automatic amino acid analyzer permits the routine analysis of taurine in preparations.

• Journal of the Korean Chemical Society
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• v.39 no.4
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• pp.257-265
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• 1995

Free amino acids were isolated from milk and their absolute amounts were determined by reversed phase high performance liquid chromatography after derivatization with dansyl chloride. The determination of D- and L-amino acids was based on achiral separation on a C18 column. It was found that milk contained totally 41.00 mg DL-amino acids in 100 mL milk. The level of D-amino acids to L-amino acids was determined by a column-switching system combining an achiral reversed phase separation and chiral chelate additive. The chiral separation was carried out with addition of the chiral Cu(N-benzyl-L-proline)2 chelate to the mobile phase in reversed phase liquid chromatography. It was found that the determination of 16 different amino acids is feasible in the milk sample with a C18 column separation and 12 D-amino acids out of the 16 amino acids can be determined via the column-switching system with chiral separation. 2.05% of D-glutamic acid and 2.93% of D-alanine were found in milk.

• Analytical Science and Technology
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• v.22 no.2
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• pp.148-151
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• 2009

Enantiomer separation of N-fluorenylmethoxycarbonyl (FMOC) $\alpha$-amino acid was performed on covalently immobilized chiral column (Chiralpak IB) based on polysaccharide derivative as a chiral selector by reversed phase liquid chromatography. The effect of the reversed mobile phase on the chromatographic parameters of the enantioselectivities, resolution factors and retention times using covalently immobilized Chiralpak IB was shown. Also the enantiomer separation of N-FMOC $\alpha$-amino acid in the reversed and normal phase was compared and the results obtained in the former mobile phase were generally lower than those in the latter mobile phase.

• KSBB Journal
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• v.30 no.4
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• pp.197-201
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• 2015

Liquid chromatographic enantiomer separation of ${\alpha}$-amino acids and their methyl and ethyl esters as fluorenylmethoxycarbonyl (FMOC) derivatives was performed using a recently developed chiral column (Chiralpak IE) based on polysaccharide derivative under simultaneous UV detection and fluorescence detection. The degree of enantiomer separation of ${\alpha}$-amino acid esters as FMOC derivatives is generally higher than that of the corresponding ${\alpha}$-amino acids. Especially, ${\alpha}$-amino acid methyl esters showed the greatest enantioseparation. As this method developed in this study can be applied to determine the chemical and optical purity of ${\alpha}$-amino acids and esters, it is expected to be quite useful for their chiral separation using Chiralpak IE.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.320-324
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• 2003

The protein hydrolysis with 6 M formic acid containing 0.3% tryptamine was a superior method for amino acid analysis of standard amino acid and protein than 6 M HCI containing 0.3% tryptamine. The recoveries of standard amino acid after acid hydrolysis were more accurate in the 6 M formic acid hydrolysis than 6 M HCI hydrolysis, especially recovery of tryptophan showed higher values of 1.5 times than that of 6 M HCI hydrolysis. The results of analysis on the standard protein, bovine serum albumin, showed very similar values compared to the sequence analysis reported in the literature for the 6 M formic acid hydrolysis than 6 M HCI hydrolysis, especially in the tryptophan recovery as standard amino acid recovery. Butylthiocarbamyl - trimethylsilyl (BTC - TMS) derivatives of 22 standard amino acids were successfully resolved DB-17 capillary column. Excellent reproducibility of standard amino acid recovery and composition of bovine serum albumin were obtained with BTC-TMS derivatives.

• Applied Biological Chemistry
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• v.35 no.2
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• pp.132-138
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• 1992

For effective determination of methylthiohydantoin amino acids(MTHs) by gas liquid chromatography in the protein sequencing, derivatization with N-methyl-N-(tert.-butyl-dimethylsilyl)trifluoroacetamide(MTBSTFA), a new silylating reagents, was attempted instead of trimethylsilyl(TMSi) derivatives by N,O-bis(trimethylsilyl)trifluoroacetamide(BSTFA) used up to the present and N(O)-butyldimethylsilyl MTHs derivatized by MTBSTFA were analysed on HP-1 capillary column. Twenty one protein amino acids except cystine were indentified. Especially arginine that did not detected with TMSi derivative on packed column until now was resolved by derivatization with MTBSTFA. N(O)-butyldimethylsilyl MTHs showed multiple peaks by MTBSTFA were proline, isoleucine, glycine and tyrosine and hydroxyproline especially showed several extraneous peaks more than two. Calibration curves of N(O)-butyldimethysilyl MTHs of amino acids in the range of $2.5\;nmol{\sim}7.5\;nmole$ showed good linearity. however, those of lysine, histidine and arginine showed linearity in the range of $5.0\;nmole{\sim}15.0\;nmole$. Correlation coefficients and regression coefficients of all calibration curves were highly significant(p<0.001).

• YAKHAK HOEJI
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• v.52 no.1
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• pp.79-84
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• 2008

Alismatis Rhizoma has been used as diuretics and antiphlogistics in the Chinese oriental medicine. A trypsin inhibitor was isolated from Alismatis Rhizoma using DEAE ion exchange column, trypsin affinity column, and FPLC chromatography, and its activity and characteristics were studied. The purifed Alismatis Rhizoma trypsin inhibitor (ARTI) was estimated to be about 22 kDa. The sequence determination on N-terminal amino acid residues and 84 amino acid residues has been completed, yet no homology has been found with trypsin inhibitors reported at NCBI. ARTI did not show inhibitory activities on chymotrypsin and elastase, however it exhibited a significant inhibitory activity on bovine trypsin, and formed a complex with rat liver 10-formyltetrahydrofolate dehydrogenase.

• KSBB Journal
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• v.29 no.6
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• pp.426-431
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• 2014

pH controlled batch reactor and bubble column reactors have been developed in this research. They were used to produce high concentration of GABA and to determine optimal pH for GABA production. Glutamate decarboxylase (GAD) was isolated from recombinant E. coli and used for GABA production from monosodium glutamate (MSG). pH control was inevitable because the pH increased with MSG consumption. GAD showed highest activity at acidic conditions at pH 5.5 but the optimal pH for GABA production was pH 6.0. When 1.5 mole of MSG was used as reactant, the 1.05 mole of GABA was produced after 10 hrs batch reaction. Using bubble column reactors, 80 % of MSG was converted to GABA for 6 hrs reaction and 1.2 mole of GABA was produced.