• Journal of Microbiology and Biotechnology
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• 제5권6호
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• pp.315-318
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• 1995

Sulfanilic acid (4-aminobenzenesulfonic acid) alone is normally not permeant in bacteria but can be readily delivered via the microbial dipeptide transport system. A dipeptidyl derivative of this compound, L-phenylalanyl-L-2-sulfanilylglycine (PSG), prepared by attachment of its primary amino group to the phenylalanyl $\alpha$-glycine moiety, appeared to have a Km of 0.125 mM and a Vmax of 1.9 nmoles/ml/min ($A_{660}$, 1.0) in Escherichia coli. From competitive spectrophotometric analysis, it was found that the type of amino acids in both of the N- and C-terminals affected the kinetic power of dipeptides. The growth inhibitory effect of PSG was over 7 times more potent than that of the sulfanilic acid against E. coli, suggesting that this potential inhibition was presumably due to the increased hydrophobic nature of the sulfanilyl dipeptide.

• 대한화학회지
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• 제53권2호
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• pp.137-143
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• 2009

공유결합된 다당유도체에서 유도된 카이랄 칼럼인 Chiralpak IC을 사용하여 N-BOC $\alpha$-amino acid와 그들의 ethyl ester 유도체의 액체크로마토그래피 거울상 이성질체의 분리를 수행하였다. 다양 한 이동상에서 공유결합된 카이랄 칼럼인 Chiralpak IC에서 거울상 이성질체가 분리된 실험결과를 나 타내었으며, 광학분할의 선택성과 분리인자가 이동상에 따라 크게 영향을 받았다. 또한 동일한 이동 상에서 분석물질의 녹이는 용매에 따라 거울상 이성질체의 분리에 미치는 영향과 분석용 컬럼에서 거울상 이성질체의 분리의 여러 예를 나타내었다.

• 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.

• 생명과학회지
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• 제9권1호
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• pp.63-68
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• 1999

5-halogen substituted uridine, amino acid, peptide 및 penicillin G의 5'-amino -5' -deoxyuridine con-jugates, 5'-monophosphate uridine 유도체, 5'-monophosphate uridine -fat쇼 acid 유도체와 같은 nu-cleoside 화합물들을 화학적으로 합성한 후 이들의 항진균, 항균 및 항암 활성을 측정하였다. 5-Bromo-2',3'-O-isopropylideneuridine(6)은 Trichophyton rubrum의 성장을 억제하였다(MIC: $0.2{\mu}$g/ml). 5'-Amino-5' -deoxyuridine -penicillin G(19), 5'-amino-5'-deoxyuridine-cyclo(Phe -Asp)(20), 5-iodo-5'-amino -5' -deoxyuridine-penicillin G(22)는 항균적이었고(S. aureus에 대해 MIC가 $6.25{\mu}$g/ml) 뒤의 두 nucleoside 화합물은 항암 작용이 가장 강한 유도체이었다(L5178Y murine lymphoma cell에 대한 $IC_{50}$이 $6.5{\mu}$g/ml).

• 약학회지
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• 제44권3호
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• pp.279-282
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• 2000

The inhibition mode of S-hydroxy-2-phenylalanylaminomethyl-4-pyron ($IC_{50}=24.6{\;}{\mu}M$) on mushroom tyrosinase was investigated using L-tyrosine as a substrate. This inhibitor is the kojic acid derivative, where the C-7 hydroxyl of kojic acid was replaced by amino group and coupled to the carboxyl of L-phenylalanine. The kinetic data obtained show a competitive inhibition pattern.

• 전기화학회지
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• 제7권2호
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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.

• Journal of Microbiology and Biotechnology
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• 제16권9호
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• pp.1477-1480
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• 2006

The 63-amino-acid-encoding afsR2 is a global antibiotics-stimulating regulatory gene identified from the chromosome of Streptomyces lividans. To dissect a putative functional domain in afsR2, several afsR2-derivative deletion constructs were generated and screened for the loss of actinorhodin-stimulating capability. The afsR2-derivative construct missing a 50-bp C-terminal region significantly lost its actinorhodin-stimulating capability in S. lividans. In addition, site-directed mutagenesis on amino acid positions of #57-#61 in a 50-bp C-terminal region, some of which are conserved among known Sigma 70 family proteins, significantly changed the AfsR2's activity. These results imply that the C-terminal region of AfsR2 is functionally important for antibiotics-stimulating capability and the regulatory mechanism might be somehow related to the sigma-like domain present in the C-terminal of AfsR2.

• Applied Biological Chemistry
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• 제35권2호
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• pp.132-138
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• 1992

Methylisothiocyanate에 의한 단백질의 아미노산 배열 결정시 순차적으로 분리되어 나오는 methylthiohydantion 아미노산을 기체 크로마토그라피로 효과적으로 정성 및 정량하기위하여 새로운 silylating reagent인 N-methyl-N-(tert.-butyldimethylsily)trifluoroacetamide를 사용하여 N-tert.-butyldimethylsily MTH 유도체로 silylation 한 후 HP-1 capillary column으로 분석하였다. Cystine을 제외한 21개의 단백질 구성 아미노산을 동정할 수 있었고 지금까지 packed column에서 TMS 유도체로 동정할 수 없었던 arginine도 분리 동정되었다. 2개 이상의 peak를 나타낸 것으로는 hydroxyproline, proline, isoleucine, glycine 및 tyrosine이었고 이중 hydroxyproline은 많은 수의 peak들로 분리되었다. Lysine, histidine 및 arginine은 주입량 $5.0\;nmole{\sim}15.0\;nmole$의 범위에서 나머지는 $2.5\;nmole{\sim}7.5\;nmole$의 범위에서 상관관계를 측정한 결과 고도의 직선 상관관계를 나타내었다(p<0.001). TMS 유도체에 의한 분석은 많은 불순 peak들 때문에 정량분석에 이용할 수 없었다.

• Archives of Pharmacal Research
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• 제20권2호
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• pp.184-190
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• 1997

A new method based on the chemical reaction has been devised for the sequential analysis of reducing oligosaccharides using 8-amino-2-naphthalenesulfonic acid (ANS), a fluorescent precolumn derivatization reagent for reducing saccharides. The procedure established includes 1) the derivatization of a reducing oligosaccharide to produce a Schiff base, 2) the reduction of the base with sodium cyanoborohydride $(NaBH_3/CN), 3)$ the methoxycarbonylation of the resultant secondary amino group, 4) the cleavage of the glycoside bond next to the reducing end, based on the intramolecular acid hydrolysis by the action of a sulfonic acid group of the ANS derivative, 5) the identification of the liberated reducing end by high-performance liquid chromatography (HPLC), and finally 6) the recovery of the resultant oligosaccharide fragment from the cleavage reaction mixture. The extensive examination of the conditions for the sequential analysis of reducing oligosaccharides resulted in the procedure of simplicity , high selectivity and high recovery. This procedure was found to be useful for the sequential analysis of di-, tri- and tetrasaccharides.

• 약학회지
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• 제52권6호
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• pp.488-493
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• 2008

2-Aminothiazole ring as a bioisoster of catechol in dopamine has provided with good oral availability and lipophilic property. 2-Aminoindan, is a rigid form of dopamine, was evaluated as a dopamine D3 agonist with low neurotoxicity. Dopamine D3 agonist was evaluated as selective for the treatment of Parkinson's disease. In order to develop a novel dopamine D3 agonist, we tried to synthesize the aminothiazoloindenoxazine derivative that is a hybrid structure of aminoindenoxazine and thiazole ring. cis-2-Amino-1-indanol (2) was synthesized from 1,2-indandione-2-oxime by catalytic hydrogenation and it was treated with chloroacetyl chloride and NaH in benzene solution to give (${\pm}$)-cis-4,4a,5,9b-tetrahydroindeno[1,2-b][1,4]oxazin-3(2H)-one (6). Nitration of 6 by the mixed acid gave 8-nitro compound (7) and the carbonyl group of 7 was reduced with $LiAlH_4$ to afford compound (8). 8 was reduced to form (${\pm}$)-cis-8-amino-2,3,4,4a,5,9b-hexahydroindeno[1,2-b][1,4]oxazine (9) and finally it was cyclized with KSCN in glacial acetic acid to yield (${\pm}$)-cis-8-amino-2,3,4,4a,5,10b-hexahydrothiazolo[4,5-f]indeno[1,2-b][1,4]oxazine (10).