• YAKHAK HOEJI
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• v.37 no.1
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• pp.49-53
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• 1993

Arylalkanoic acid derivatives are known as good non-steroidal antiinflamatory and antirheumatic agents. The new arylalkanoic acid derivatives were synthesized when 2-chloro-3-($\alpha$-cyano-$\alpha$-ethoxycarbonyl-methyl)-1, 4-naphthoquinone was reacted with some arylamines.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.815-822
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• 1993

This experiment was carried out to determine the separation condition of 1-dimethylaminonaphthalene-5-sulfony(Dansyl) derivatives of amino acids by reverse-phase high performance liquid chromatography with Nova-Pak C18 column. Determined solvent system was solvent A(200mA phosphate buffer pH 6.8 15%, acetonitrile 11%, water 74%) and solvent B(acetonitrile 65%, methanol 28%, water 7%). Linear gradient of solvent B was applied from 12% to 80% for 50min. Complete separation of 20 amino acids including asparagine and glutamine which constitute protein was achieved within 50min. As the detection limit was the range of picomole, the resolution power was excellent. Reproducibility of the retention time was less than mean $\pm$0.05min. According to the above optimum chromatographic conditions, the amino acid composition of some food and human blood was examined. The most affluent amino acid was alanine in human blood, aspartic acid and glutamic acid in soy sauce, alanine and threonine in soy milk and proline in milk and yoghurt.

• Food Science and Preservation
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• v.15 no.5
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• pp.699-705
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• 2008

This study compared amino acids and effective components of Viola mandshurica produced in Korea with those of Chinese plants, as part of a study on nutritional andfunctional materials, to aid in the development of a valuable food. The contents of reducing sugar, free sugar, polyphenols, and soluble protein in the flowers of V. mandshurica were higher than in other fractions, being 10,485.11 mg%, 118.85 mg%, 1,259.26 mg%, and 23.67 mg%, respectively. Total flavonoid content of Chinese leaves was the highest at 2,370.75 mg%, followed by 1,844.43 mg% in Korean leaves. Free amino acids were highest in Korean leaves (5,345.21 mg%), followed by roots (4,692.24 mg%), flowers (3,807.87 mg%), and leaves of China plants (3,613.81 mg%). Arginine accounted for 55% of free amino acids in the roots, and all plant fractions contained more valine, aspartic acid, glutamic acid, alanine, and arginine, than other amino acids. The total content of amino acid derivatives was the highest (9,058.80 mg%) in Korean leaves. Especially, $\alpha$-aminoadipic acid constituted over 50% of total amino acid derivatives in all plant parts of V. mandshurica. When mineral contents were analyzed, leaves grown in China showed the highest content of 5,917.57 mg%, and the contents of K, Ca, and Mg were much greater than those of other minerals, together comprising over 95% of total mineral content in leaves and flowers from Korea.

• YAKHAK HOEJI
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• v.27 no.4
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• pp.289-293
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• 1983

Twelve new N-piperoyl amino acids were synthesized by acylation of amino acids with piperoylchloride in order to develop the new central nervous depressants. Silylation of the carboxylic group of amino acids not only precluded side reactions but-also facilitated acylation at room temperature without catalysts. The acute toxicity of all the synthesized compounds were lower than that of piperine itself, whereas they showed strong protective effect against the strychnine-induced mortality.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.506-514
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• 2010

A new series of ligands N-[(benzoylamino)-thioxomethyl]-amino acid (HL) were synthesized by reaction of benzoylisothiocyanate with various amino acids namely aspartic acid [BATA] (1), glutamic acid [BATG] (2), methionine [BATM] (3), leucine [BATL] (4), and tryptophan [BATT] (5). The ligands were characterized by elemental analysis, IR and NMR spectra. Some transition metal complexes ($ML_2$) for these ligands (6-8) were prepared; [M=Cu(II), Co(II), or Ni(II)], and characterized by elemental analysis, IR and $^1H$ NMR spectra. Antibacterial study showed that all the ligands have no antibacterial activity, whereas ($ML_2$) complexes; [M = Cu(II), Co(II), or Ni(II)] have antibacterial activity towards (Gram -ive) Escherichia (NCTC5933) and (Gram +ive) Staphylococcus (NCTC6571) and have no toxicity on (BALB/C) Albino mice.

• Analytical Science and Technology
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• v.36 no.4
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• pp.143-151
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• 2023

Considering the greater role of α-amino acids in our daily lives, the enantiomer resolution of seven α-amino acids derivatized with fluorogenic reagent (4-fluoro-7-nitro-2,1,3-benzoxadiazole, NBD-F) by chiral HPLC on amylose or cellulose trisphenylcarbamate derived chiral stationary phases (CSPs) under simultaneous ultraviolet (UV) and fluorescence (FL) detection was performed. The degree of enantioseparation and resolution was affected by nature and selector backbones of the CSPs as well as the kind of amino acids. Baseline enantiomer separation and resolutions were observed for the enantiomers of all analytes as NBD derivatives especially on coated type amylose tris(3,5-dimethylphenylcarbamate) derived CSPs (Chiralpak AD-H and Lux Amylose-1). The other CSPs also showed good enantioselectivity except for the CSPs (Chiralpak IB, Chiralcel OD-H and Lux Cellulose-1) having cellulose tris(3,5-dimethylphenylcarbamate) as chiral selectors. The developed analytical chiral method was applied to determine the enantiomeric purity of seven commercially available L-α-amino acids and the impurities as D-forms were found to be in the range 0.08-0.87 %, respectively. The intra- and interday accuracy and precision assays showed high accuracy and precision of the developed analytical method. This chiral HPLC method for the enantiomer resolution of amino acids using fluorescent derivatization could be useful for the determination of enantiomeric purity of pharmaceuticals and biological study for amino acid type compounds among chiral drugs.

• Journal of Life Science
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• v.8 no.4
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• pp.395-399
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• 1998

Neurokinin A(NKA) and its derivatives ([Nle$^{7}$NKA,[Leu$^{7}$NKA] were synthesized by solid phase peptide synthesis method using Fmoc-TFA strategy and their smooth muscle contractile activities were measured to examine the structural effect of alkyl group at the 7th amino acid NKA on the smooth muscle contractile activity. The smooth muscle contractile activity. The smooth muscle contractile activities of [Nle$^{7}$]NKA and [Leu$^{7}$]NKA were only 5.64% and 1.55%, respectively when compared with NKA. This result suggested that the more three dimensional structure of th 7th amino acid as well as the whole message segment of NKA would be necessary to show the biological activity.

• Journal of the Korean Graphic Arts Communication Society
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• v.1 no.1
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• pp.69-75
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• 1983

Among the gelatin hardness for photographic emulsion, the formal dehyde , dialdehydes, n-Methylol compounds, ketonea, carbonylic acid and carbamic acid derivatives, and s-Triazine derivatives were studied. The greater purts of hardeners formed cross-link by the reaction with ${\varepsilon}$-Amino group in the lysine and OH group in the hydroxylysine. Glutaraldehyde produced most stable cross-link due to the formation of pyridinum ion. 2.5 hexanedione and 3-hexone-2.5-dione possible to use as the ketone hardner . The sodium salt of 2.4-dichloro-6-hydroxy-S-Triazine was newly developed as the olefinic hardners for emulsion.lsion.

• YAKHAK HOEJI
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• v.33 no.2
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• pp.129-139
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• 1989

New diamide chiral stationary phases of four systematically substituted optically active N-(N-benzoyl-L-amino acid)-anilide synthesized from L-valine, L-leucine, L-isoleucine, and L-phenylalanine were described. The behaviors of these diamides as optically active stationary phases for the separation of N-trifluoroacetyl-D,L-amino acids were examined with respect to separation factors(${\alpha}$) and thermodynamic properties of interaction. The separation of twelve N-trifluoroacetyl-D,L-amino acid isopropyl esters were improved by the order of N-(N-benzoyl-L-leucyl)-anilide>N-(N-benzoyl-L-isoleucyl)-anilide>N-(N-benzoyl-L-valyl)-anilide>N-(N-benzoyl-L-phenylalanyl)-anilide. Eight amino acid derivatives with non-polar R-group and threonine, serine, aspartic acid, and glutamic acid enantiomers were separated on N-(N-benzoyl-L-leucyl)-anilide as chiral stationary phase with good separation factor between 1.07-1.25. The separation factors decreased with respect to increasing column temperature. Possible working temperature of diamide phase was between $130-190^{\circ}C$ for N-(N-benzoyl-L-phenylalanyl)-anilide and $130-180^{\circ}C$ for other three diamide phases. The differential Gibb's free energy (${\Delta}{\Delta}G$) of enantiomers was in the range of -100--180 cal/mol for ten amino acids and -40--60 cal/mol for alanine and aspartic acid.

• Journal of the Korean Electrochemical Society
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• v.7 no.2
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• pp.83-88
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• 2004

[ $DeniLite^{TM}$ ] laccase immobilized Pt electrode was used for amperometric detection of some catechol derivatives and o-aminophenol (OAP) derivative by means of substrate recycling. In case of catechol derivatives, the obtained sensitivities are 85, 79 and $57 nA/{\mu}M$ with linear ranges of $0.6\~30,\;0.6\~30\;and\; 1\~25 {\mu}M$ and detection limits (S/N=3) of 0.2, 0.2 and $0.3{\mu}M$ for 3,4-dihydroxycinnaminic acid (3,4-DHCA), 3,4-dihydroxybenzoic acid (3,4-DHBA) and 3,4-dihydroxyphenylacetic acid (3,4-DHPAA), respectively. In case of OAP derivative, the obtained sensitivity is $237 nA/{\mu}M$ with linear range of $0.2\~15{\mu}M$ and detection limit of 70 nM for 2-amino-4-chlorophenol (2-A-4-CP). The response time $(t_{90\%})$ is about 2 seconds for each substrate and the long-term stability is around 40-50days for catechol derivatives and 30 days for 2-A-4-CP with retaining $80\%$ of initial activity. The optimal pHs of the sensor for these substrates are in the range of 4.5-5.0, which indicates that stability of the enzymatically oxidized product plays a very important role in substrate recycling. The different sensitivity of the sensor for each substrate can be explained by the electronic effect of the sugstituent on the enzymatically oxidized form.