• 한국미생물·생명공학회지
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• 제2권2호
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• pp.121-122
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• 1974

• 분석과학
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• 제7권1호
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• pp.53-64
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• 1994

아미노산의 광학 이성질체를 분리하는 방법을 확립하고 식품이나 생체에 있는 광학이성질체를 분리 정량하여 영양학이나 생화학적 관계를 연구한다. 필수아미노산 20종을 포함하여 총 38종의 d, l-from 아미노산을 검색 대상으로 삼았다. 단백질은 한국산 콩, 된장, 고추장, 간장, 분유 및 환자의 백내장을 시료로 하여 산 가수분해 후 esterification과 acylation으로 TFA-IPA 유도체를 만들어 chirasil val GLC column을 사용하여 분리하였다. 이성질화가 일어나는 아미노산은 alanine, aspartic acid, glutamic acid, phenyl alanine으로 식물성 시료인 된장에서는 d-alanine이 검출되었으나 동물성 시료인 백내장과 분유에서는 검출되지 않았다. 연령추정 등 생리적으로 이용이 가장 적적한 것은 분리능과 함량을 비교했을 때 aspartic acid였다. d-from 아미노산의 분율은 가정용 된장이 3~6, 시판용 된장이 약 3%, 간장이 2~4%, 콩이 약 1%, 백내장 시료에서 1~2%, 분유에서 1.0~1.5%로 검출되었으며, 숙성 발효시 광학이성질체의 변환이 현저함을 알 수 있다.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3191-3195
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• 2012

New silver nanoparticle (AgNP)-loaded amino acid based hydrogels were synthesized successfully from poly (vinyl alcohol) (PVA) and poly(acryl amide-co-acryloyl phenyl alanine) (PAA) by redox polymerization. The formation of AgNP in hydrogels was confirmed by using a UV-Vis spectrophotometer and XRD. The structure and morphology of silver nanocomposite hydrogels were studied by using a scanning electron microscopy (SEM), which demonstrated scattered nanoparticles, ca. 10-20 nm. Thermogravimetric analysis revealed large differences of weight loss (i.e., 48%) between the prestine hydrogel and silver nanocomposite. The antibacterial studies of AgNP-loaded PAA (Ag-PAA) hydrogels was evaluated against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) bacteria. These Ag-PAA hydrogels showed significant activities against all the test bacteria. Newly developed hydrogels could be used for medical applications, such as artificial burn dressings.

• 대한화학회지
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• 제5권1호
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• pp.33-37
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• 1961

We have shown that carboxy-peptidase destroys the biological activity of angiotensin octa-and deca-peptides. Since Proline occurs as the seventh amino acid from the amino end of the chain and since carboxypeptidase does not cleave proline from a peptid chain, it is evident that the heptapeptid H.asp-arg-val-tyr-ileu-his-pro.OH is formed by this hydrolysis. This peptide must then be biologically inactive. In order to determine whether the phenyl group of the C-terminal amino acid was the necessary requirement for biological activity of the octapeptide, $ala^8$ angiotensin octapeptide(amino acids of peptides numbered from amino end) was synthesized. For this synthesis the four dipeptides were prepared: carbobenzoxy-L-prolyl-L-alanine-P-nitrobenzyl-ester, m.p. $134-135^{\circ}C,$ carbobenzoxy-L-isoleucyl-imidazole benzyl-L-histidine methyl ester, m.p. $114-116^{\circ}C,$ carbobenzoxy-L-valyl-L-tyrosine hydrazide and carbobenzoxy B-benzyl-L-aspartyl-nitro-L-arginine. The first three dipeptides were obtained as crystalline compounds. Imidazole-benzyl-L-histidine was used in the hope that it would block the histidine imidazole against side reactions in steps subsequent to the formation of the C-terminal tetrapeptide. Also, it was through that the imidazole benzylated peptides would be easier to crystallize. This, however, was not the case. The tetrapeptide, carbobenzoxy-L-isoleucyl-L-im, benzyl-histidyl, L-prolyl-L-alanine-nitrobenzyl ester was not obtained in a crystalline form. Neither could the mono-or dihydrobromide of the tetrapeptide free base be induced to crystallize. Carbobenzoxy-L-valyl-L-tyrosine azide was condensed with the tetrapeptide free base to yield the protected hexapeptide; carbobenzoxy-L-valyl-L-tyrosyl-L-isoleucyl-L-im, benzyl, histidyl-L-Prolyl-L-alanine-nitrobenzyl ester. Upon removal of the carbobenzoxy group with hydrogen bromide in acetic acid an amorphous free base hexapeptide ester was obtained. This compound gave the correct C, H, N analysis and contained the six amino acids in the correct ratio. The octapeptide was obtained by condensing this hexapeptide with carbobenzoxy-B-benzyl-L-aspartyl-nitro, L-arginine using the mixed anhydride method of condensation. This amorphous product was proven to be homogenous by chromatography in two solvent systems and upon hydrolysis yielded the eight amino acids in correct ratio. The five protecting groups were removed from the octapeptide by hydrogenolysis over palladium black catalyst. Biological assay of the free peptide indicated that it possessed less than 0.1 per cent of both pressor and oxytocic activity of the phenylalanine8 angiotensin. This suggests that the phenyl group is a point of attachment between angiotensin and its biological receptor site.

• Journal of Ginseng Research
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• 제14권2호
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• pp.117-121
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• 1990

Browning intensity is a major factor to estimate the quality of red ginseng or red ginseng products. The Maillard type of browning reaction proceeds nonenzymatically during extraction and concentration of red ginseng. The present studies were carried out to investigate the effects of amino acids and sugars on the browning reaction during extraction and concentration of red ginseng. Red ginseng was pulverized to 115 mesh and then tenfold (v/w) of water was added to the powder to make the substrate of red ginseng. Solution (0.1 M) of fourteen amino acids and of folly silgars were added to the substrates of red ginseng powder and these were then extracted and concentrated to examine their browning intensities. Amino acids were more effective than sligars in acrelerating the browning reaction. Acceleration of the browning reaction in the concentrate was in the order of arginine> histidine>glycine>alanine>lysine phenyl alanine>aspartic acid>lelicine>threonine>gllitamic acid>tyrosine>valine>istleucine>methionine for amino acids, and was glucose>frlictose >silcrose, maltose for sugars.

• Archives of Pharmacal Research
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• 제16권3호
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• pp.180-185
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• 1993

The acid dissociation constants of certain Schiff bases derived from isatin with p-substituted benzoyl hydrazines and somee amino acids of glycine, $\beta$-and $\alpha$-alanine, valine, $\beta$-phenyl-$\alpha$-alanine and anthranilic acid have been detemined potentiometrically at different temperatures in different aquo-organic solvent mixtures (ethnol, dioxane, dimethyl formamide, methanol, acetone and tetrahydrofurance). The pKa values were demonstrated on the light of the different electornic and steric effects of the substituents and the sovlent characteristics. In all the mixed media used, ionization of the compounds decreased by increasing the mole fraction of the organic cosolvent. Theemodynamic parameters $(\Delta{H}^\circ,\;\Delta{G}^\circ,\;\Delta{S}^\circ)$ were evaluated. The structural effects of the investigated compounds on these parameters were reported and discussed.

• 약학회지
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• 제30권1호
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• pp.47-50
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• 1986

The enantiomers of five amino acids (alanine, valine, threonine, leucine and phenylalanine) could be separated by gas chromatography with optically active (S)-5-isopropyll-$N^3$-phenyl-2-thiohydantoinic stationary phase, which prepared from L-valine and phenylisothiocyanate. Gas chromatographic separations on methylesterificated and N-trifluoroacetylated amino acids have been conducted in isothermal at several column temperatures (180~190, 200, $210^{\circ}C$). The separation factors were 1.29 (alanine, $190^{\circ}C$), 1.35 (valine, $190^{\circ}C$), 1.33 (threonine, $190^{\circ}C$), 1.17 (leucine, $190^{\circ}C$) and 1.05 (phenylalanine, $190^{\circ}C$) and D-isomers eluted prior to L-isomers in every instance. The result of this experiment shows that this stationary phase can be used for the separation of the other amino acids enantiomers.

• Toxicological Research
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• 제14권3호
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• pp.365-370
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• 1998

To evaluate the renal toxicity of the antitumor agent, p-{N,N,-Bis(2-chloroethyl)amino}-4-phenyl acetyl-amino-2,6-piperidinedione(CK-15), rats were treated with CK-15 (acute: 50mg/kg. i.p., single and subacute: 5mg/kg, i.p., daily for 7 days). The changes in the body weight, water consumption, kidney weights and urine volume after and during the treatment were observed. The concentrations of urinary creatinine and portein, the activities of N-acetyl-${\beta}$-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), ${\gamma}$-glutamyl transpeptidase (${\gamma}$-GT) and lactate dehydrogenase (LDH) in 24hr urine were also determined. The body weight, water consumption, and urine volume were decreased after the acute and subacute administration. However the weights of kidney were not changed after the treatments. The excretion of creatinine was significantly decreased 1 day after acute administration but, returned to the control value. In subactute administration, the excretion of creatinine was gradually decreased. However, the protein excretion did not changed in both treatment. Those indicate that CK-15 might decrease the metabolic rate of muscle. THe urinary activities of NAG, AAP, ${\gamma}$-GT, and LDH were significantly affected bythe drug treatment. The urinary activities of NAG, AAP and ${\gamma}$-GT were significantly increased 1 day after the acute administration and then returned to the control value. However, the urinary activities of LDH were not changed in acute treatment. In subacute treatment, although the urinary activities of NAG were not changed, those of AAP and ${\gamma}$-GT were significantly increased 2.3 times at 3 days during the subacute administration. Also the urinary activities of LDH were significantly increased at 7 day after the administration. These results indicate that the high and subacute administration might induce a damage in the kidney cells. Furthermore the present results suggest that the toxic effects of CK-15 might be due to the accumulation of the metabolites.

• 공업화학
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• 제4권2호
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• pp.254-263
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• 1993

아미노산공업은 추출법으로부터 합성법, 발효법으로 발전되어 왔다. 현재 일부의 아미노산(L-cytine, L-tyrosine 등)은 추출법으로 제조하고 있지만 대부분의 아미노산은 합성법, 발효법에 의해서 생산되고 있다. 이중 합성법은 유독의 시안화수소를 이용하며, 산 및 알카리에 의한 가수분해과정에서 다량의 공업폐수가 발생한다. 이러한 관점에서 환경에 미치는 영향을 고려하여 개량된 새로운 합성법이 요구되고 있다. 본 총설에서는 근년에 주목받고 있는 phenyl alanine의 새로운 합성법에 대해서 소개하고 보다 특수한 아미노산을 합성하기 위해서 전구체인 ${\alpha}$-케토산 유도체의 합성법에 대해서 최근의 연구결과를 소개한다.

• Mycobiology
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• 제29권4호
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• pp.198-204
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• 2001

Analysis of leaf exudates of Vicia faba using paper chromatography to identify individual amino acids and sugars qualitatively was investigated. The results revealed that the number of identified amino acids detected in the leaf exudates of the susceptible plants was more than those of resistant plants. The results also showed an increase in the number of amino acids exuded by infected leaves, but no marked difference in sugars of infected and non infected plants. Lithium chloride application led to decrease in amino acid and sugar contents. The number of amino acids and sugars was also decreased with leaf age. Botrytis fabae and the selected fungal species(Alternaria alternata, Fusarium oxysporum and Aspergillus niger) were used to show the effect of individual amino acid and sugar on their spore germination. It was observed that all amino acids stimulated the fungal spore germination except serine which inhibited its spore germination. In case of A. alternata, spore germination was stimulated by all amino acids except serine, alanine, glutamic acid, arginine and methionine which caused the inhibition. In case of F. oxysporum, aspartic and glutamic acids inhibited spore germination but the other amino acids stimulated its spore germination. Aspartic acid and phenyl alanine inhibited the spore germination of A. niger. All the identified sugars(galactose, glucose, fructose and rhamnose) stimulated spore germination of all tested fungi.