• KSBB Journal
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• v.26 no.2
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• pp.139-142
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• 2011

The chromatographic enantiomer separation of 9-anthraldimine derivatives of ${\alpha}$-amino acid methyl and ethyl esters on four polysaccharide based chiral columns was performed. The 9-anthraldehyde Schiff base derivatives of ${\alpha}$- amino acid esters were readily synthesized by stirring the ${\alpha}$- amino acid ester hydrochloride salts with 9-anthraldehyde in the presence of 1,8-diazabicyclo [5.4.0]undec-7-ene as a base and anhydrous $MgSO_4$. Chiralcel OD or Chiralcel OD-H showed the greatest enantiomer resolution of 9-anthraldimine derivatives of ${\alpha}$-amino acid methyl and ethyl esters. The L-enantiomers of all the analytes were preferentially retained on Chiralcel OD or Chiralcel OD-H. This analytical method was applied in the determination of optical purities of several commercially available D- or L-${\alpha}$-amino acid methyl esters.

• The Korean Journal of Food And Nutrition
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• v.32 no.4
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• pp.342-348
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• 2019

The objective of this study was to investigate the changes in flavor components of cheonggugjang prepared with hazelnut. Amino nitrogen content in cheonggukjang was significantly lower in the 30~40% hazelnut group compared to the control group. The volatile basic nitrogen of hazelnut added cheongkukjang showed a similar pattern to that of amino nitrogen. The number of B. subtilis was slightly increased in relation to the amount of hazelnut added, but there was no significant difference. The content of glucose increased proportionally with increasing hazelnut. Total amino acid content decreased with increasing hazelnut. The ratio of glutamic acid to total free amino acids increased with increasing hazelnut. Oleic acid content increased proportionally with increasing hazelnut, while linoleic acid content decreased. In conclusion, the addition of hazelnut may contribute to the quality diversification of cheonggukjang by changing the taste and flavor while maintaining the amino nitrogen content of cheonggukjang.

• The Korean Journal of Food & Health Convergence
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• v.6 no.6
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• pp.1-7
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• 2020

We compared the fermentation of 0 to 4 weeks by manufacturing a rapid low salt-fermented seahorse with a commercial Protamex added to the functional food, Hippocampus abdominalis. We studied amino acid composition, content and major amino acids related to flavor during the fermentation process of salt-fermented seahorse. In the enzyme-free group, it showed little change in the content of non-protein nitrogenous compounds, the content of amino acids and degree of hydrolysis. The Protamex enzyme treatment group was rapidly hydrolyzed in one week of ripening, resulting in increased non-protein nitrogenous compounds content, amino acid content and degree of hydrolysis, and minimal changes in the four weeks. The total amino acid contents ratio showed the highest content of glutamic acid in the enzyme additive group, glycine, alanine, which indicates sweet taste, and serine, the content of glycine, alanine, serine, and lysine, indicating sweet taste, has increased significantly over the enzyme-free group. Twenty species of free amino acid in the four-week of salt-fermented seahorse were detected. It detected 43.0% (6 species) in the enzyme-free group and 63.96% (7 species) in the enzyme additive group.

• Journal of Plant Biotechnology
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• v.48 no.4
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• pp.228-235
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• 2021

The amino acids found in plants play important roles in protein biosynthesis, signaling processes, and stress responses, and as components in other biosynthesis pathways. Amino acid degradation helps maintain plant cells' energy states under certain carbon starvation conditions. Branched-chain amino acid transferases (BCATs) play an essential role in the metabolism of branched-chain amino acids (BCAAs) such as isoleucine, leucine and valine. In this paper, we performed genome-wide RNA-seq analysis using CsBCAT7-overexpressing Arabidopsis plants. We observed significant changes in genes related to flowering time and genes that are germination-responsive in transgenic plants. RNA-seq and RT-qPCR analyses revealed that the expression levels of some BCAA catabolic genes were upregulated in these same transgenic plants, and that this correlated with a delay in their senescence phenotype when the plants were placed in extended darkness conditions. These results suggest a connection between BCAT and the genes implicated in BCAA catabolism.

• Journal of Environmental Science International
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• v.32 no.3
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• pp.191-195
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• 2023

This study aimed to investigate the effect of amino acid additives to weaned piglet diets on the pH and volatile fatty acids of pig slurries. A total of 135 weaned 22 -day-old piglets (Yorkshire x Landrace x Duroc) were used in this 56-d study. The three dietary treatments were as follows: (1) Control as a basal diet, (2) 1% amino acid additive and (3) 2% amino acid additive. Both pH and acetic acid values at 71 and 78 days were significantly different in all treatment groups (p<0.05). In addition, significant differences in propionic acid values were observed among treatment groups at 64 and 78 days (p<0.05). However, pH, acetic acid, and propionic acid values did not differ between 1% and 2% amino acid treatment groups. In conclusion, adding 1% and 2% amino acid to weaned piglet diets reduced the pH, acetic acid and propionic acid contents of pig slurries by acting as a probiotic. This may help formulate increase management strategies for improving the pig housing environment.

• Korean Journal of Food Science and Technology
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• v.5 no.2
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• pp.71-77
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• 1973

The results, which was analytically surveyed the free amino acids by the automatic amino acid analyzer adding the enzyme on the Korean cow's fore shank muscles, are as follows: 1. The content of free amino acids in the fore shank muscles, without addition of the enzyme orderly contains alanine, glutamic acid, lysine, glycine, histidine, leucine, threonine, arginine, cystine, serine, proline, isoleucine, phenylalanine, tyrosine, methionine, aspartic acid and valine. 2. In accordance with the addition of the enzyme, by 0.01%, 0.05% and 0.1% the nine free amino acids of glutamic acid, glycine, alanine, cystine, valine, isoleucine, leucine, lysine and arginine were continuosly increased. 3. Proline and histidine were decreased at the enzyme addition of 0.01% after showing the high content at the control, but the quantity of free amino acids was increased according to the increase of the quantity of the enzyme. 4. Aspartic acid, threonine, serine, methionine, tyrosine and phenylalanine were increased till the enzyme addition of 0.05% and remarkably decreased from 0.1%. 5. At cooking the meat, the quantity of the enzyme addition was most effective at 0.05% of meat weight.

• Journal of Mushroom
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• v.18 no.1
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• pp.107-114
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• 2020

Fifteen species of wild mushrooms, which are classified as edible, medicinal, poisonous, or unknown types, were analyzed for their free amino acid contents. The average total amino acid content was 1,120.0 mg/kg in the edible type, 1,037.8 mg/kg in the medicinal type, and 1,010.8 mg/kg in the poisonous or unknown type, respectively. The edible type wild mushrooms showed the highest average content of total essential amino acids; conversely, the poisonous or unknown type showed the lowest content. Leucopaxillus giganteus (OK811) showed the highest total amino acid (1,212.4 mg/kg) and essential amino acid (490.2 mg/kg) contents among edible type, while Pycnoporus sanguineus (OK1071) showed the highest total amino acid (1,233.7 mg/kg) and essential amino acid (412.8 mg/kg) contents among the medicinal type. Among the poisonous or unknown type, Hypholoma fasciculare (OK826) showed the highest total amino acid (1,223.4 mg/kg) and essential amino acid (442.8 mg/kg) contents. The amino acid contents of wild mushrooms are fundamental data for the screening of useful genetic resources with nutritionally superior properties.

• Applied Biological Chemistry
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• v.8
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• pp.11-20
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• 1967

In order to study the change of nitrogeneous compounds during the "Natto" preparation, the contents of insoluble protein, water soluble protein and amino nitrogen were determined and the pattern of peptides and amino acids was investigated by paper chromatography for the fractions resulting from molecular sieving. The results are summarized as follows: 1. Insoluble protein nitrogen which was increased to 84% by autoclaving the native soybean decreased to 44%, whereas the trichloroacetic acid soluble nitrogen increased from 8% to 45% during Natto preparation, But the soluble protein nitrogen showed a slight increase. 2. Fractionation of the peptides using Dowex-50 resins showed that they consisted mostly of lower molecular weight peptides which increased in accordance with the progress of fermentation, especially after 30-hour period. 3. Sixteen known and two unknown amino acids, and three peptides with different Rf values were identified during the Natto preparation. Their appearance showed some difference in that phenylalanine appeared after 10 hours, methionine, after 20 hours and proline, after 30 hours, respectively. The three peptides appeared at the different stage of fermentation.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.58-62
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• 1989

Free amino acids in water-extracts and total amino acids in hydrolysates of three cultivated mushrooms, Agaricus bisporus, Pleurotus ostreatus and Lentinus edodes were analyzed by amino acid analyzer to know the compositional differences depending on species and portions (pileus and stipe). Eighteen amino acids were identified and quantified. The total nitrogen and protein nitrogen contents were in the range of 1.67-6.24% and 0.88-2.42% (dry basis), respectively. The considerable differences were often found among species and portions of mushrooms. All of them were found to be higher in the pileus part. The free amino acids conents in water-extracts were in the range of 10.04-37.85mg/g(dry weight) and the total amino acids contents in hydrolysates were in the range of 53.37-120.15mg/g(dry weight). Glutamic acid, serine, histidine, and alanine were dominent in the free amino acids pool and glutamic, aspartic acid, histidine, and alanine were in the total amino acids pool.

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1665-1669
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• 2007

A direct regioselective α-hydroxyamination of α-branched aldehydes with nitrosobenzene using cis-5-benzylproline as catalyst has been developed for the preparation of α-hydroxyamino aldehydes possessing a quaternary carbon center. Such compounds are versatile building blocks for the synthesis of quaternary α- amino acids, β-amino alcohols, and 1,2-diamines.