• Biotechnology and Bioprocess Engineering:BBE
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• 제8권1호
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• pp.1-8
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• 2003

With current developments in enzyme-catalyzed reactions and techniques available for rational redesign of natural biocatalysts, the enzymatic biosynthesis can become one of the most valuable Synthetic methods. Enzymatic regioselective catalysis in organic media has played a key role in pursuing asymmetric synthesis for active chiral compounds. Here, we shortly do-scribe some historical issues of the rapidly growing area, enzymatic catalysis in synthetic organic chemistry and then review researches that have been carried out in the regioselective enzymatic catalysis for the past two decades. An application of this technology to the modification of some potential target drug co m pound will be adios presented.

• Journal of Microbiology and Biotechnology
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• 제28권4호
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• pp.566-570
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• 2018

Because glycosylation of aesculetin and its 6-glucoside, aesculin, enhances their biological activities and physicochemical properties, whole-cell biotransformation and enzymatic synthesis methodologies using Neisseria polysaccharea amylosucrase were compared to determine the optimal production method for glycoside derivatives. High-performance liquid chromatography analysis of reaction products revealed two glycosylated products (AGG1 and AGG2) when aesculin was used as an acceptor, and three products (AG1, AG2, and AG3) when using aesculetin. The whole-cell biotransformation production yields of the major transfer products for each acceptor (AGG1 and AG1) were 85% and 25%, respectively, compared with 68% and 14% for enzymatic synthesis. These results indicate that whole-cell biotransformation is more efficient than enzymatic synthesis for the production of glycoside derivatives.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.329-332
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• 2001

It has been known that, in enzymatic synthesis of cephalexin, the conversion yield was reduced by high loading of ampicillin acylase. In order to elucidate this phenomena, pH-controlled synthesis of cephalexin was examined using a purified Acetobacter turbidans acylase. When the pH of the reaction mixture was maintained at $6.20{\pm}0.04$, the reduction of the maximal conversion rate was not observed even with high enzyme loading. The kinetic parameters also suggest that pH drop during the enzymatic synthesis of cephalexin was mainly attributed to the rapid hydrolysis of D-${\alpha}$-phenylglycine methyl ester to D-${\alpha}$-phenylglycine, rather than the disappearance of 7-amino-3-deacetoxycephalosporanic acid for cephalexin synthesis. At higher molar ratio of two substrates, [D-${\alpha}$-phenylglycine methyl ester]/[7-amino-3-deacetoxycephalosporanic acid], the conversion rate was also elevated under pH-controlled enzymatic synthesis, which implies that the main reason for the pH drop is due to the production of D-${\alpha}$-phenylglycine methyl easter, the effect of a water-methanol cosolvent system on the ester, the effect of a water-methanol cosolvent system on the conversion profile was also examined. Even the though the conversion rate was increased in 10% methanol solution, a higher than 16% methanol in the reaction mixture caused an inactivation of enzyme.

• 식품보건융합연구
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• 제10권2호
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• pp.7-11
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• 2024

Glutathione (GSH) is a vital compound composed of glutamic acid, cysteine, and glycine, crucial for cellular functions including oxidative stress defense and detoxification. It has widespread applications in pharmaceuticals, cosmetics, and food industries due to its antioxidant properties and immune system support. Two primary methods for GSH synthesis are enzymatic and microbial fermentation. Enzymatic synthesis is efficient but costly, while microbial fermentation, particularly using yeast strains like Candida albicans, offers a cost-effective alternative. This study focuses on genetically modifying C. albicans mutants, specifically targeting glutathione reductase (GLR1) and gamma-glutamylcysteine synthetase (GCS1) genes, integral to GSH synthesis. By optimizing these mutants, the research aims to develop a model for efficient GSH production, potentially expanding its applications in the food industry.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.490-493
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• 2003

Enzymatic synthesis of sugar fatty acid esters was investigated in organic solvent using Candida rugosa lipase. To overcome sugars insolubility in organic solvent, sugar absorption procedure was done on a silica gel. The product yield was determined by using ion Chromatography, with various factors such as reaction time, enzyme fatty acid molar ratio, number of carbon in fatty acid.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.597-600
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• 2000

In this study the enzymatic synthesis of ester-linked conjugates of amino acid and monosaccharide in pyridine was tested by the catalysis of Optimase M-440, an alkaline serine pretense. Optimase M-440 showed the higher activity in the reaction of monosaccharides which have one or more primary -OH groups. And also Optimase M-440 showed high regioselectivity; The transesterification of primary -OH group selectively occurred.

• Korean Chemical Engineering Research
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• 제51권6호
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• pp.716-726
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• 2013

가수분해 효소(혹은 아실전이효소)를 이용한 알콜과 아민의 아실반응은 에스터의 가수분해 반응(hydrolysis, deacylation)과 더불어 효소를 이용한 유기합성 반응에서 이미 잘 확립된 기술로서, 산업체에서 제약의 합성이나 고분자의 합성에서 널리 응용되고 있다. 이러한 효소를 이용한 아실화 반응은 주로 열역학적인 제한으로 인해 그동안 대부분이 주로 유기용매에서 이루어지고 있다. 최근 들어서, 수용액에서 아실화반응을 전이효소를 이용하여 효율적으로 할 수 있다는 보고와 함께 그 반응 기제에 대한 연구들이, X-ray 구조와 이러한 반응을 가능하게 하는 효소의 단백질 서열 비교 연구, 그리고 계산 화학에 의한 효소의 설계 연구등을 통해 새롭게 밝혀지고 있다. 본 총설에서는 효소를 이용한 아실화반응을 유기용매와 수용액에서의 수행함에 있어서 장단점을 비교해 보면서, 앞으로의 전망도 함께 제시하고자 한다. 특별히 다양한 천연물들의 구조 변화에 아실화 반응 생체촉매를 사용할 수 있는 가능성에 대해 살펴볼 것이다.

• 한국연초학회지
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• 제25권1호
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• pp.70-79
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• 2003

$\beta$ -Glucosidase-catalysed synthesis of glucosides with aromatic alcohols and monoterpene alcohols as accepters and cellobiose as a donor in the presence of various commercial $\beta$ -glucosidases were described. $\beta$ -Glucosidases from Aspergillus niger spp,. Trichoderma spp., Penicillium sup. and bitter almond have been shown to catalyze synthesis of $\beta$ -glucosides of benzyl alcohol, 2-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol, 2-phenylethyl alcohol, geraniol and citronellol in the presence of cellobiose as sugar donor. Among enzyme preparations tested, each $\beta$ -glucosides prepared from Aspergillus niger were isolated in the pure state by Diaion HP-20 and silica gel column chromatography. The products were identified as $\beta$ -glucosyl products of benzyl alcohol, 2-hydroxyhenzyl alcohol, 4-hydroxybenzyl alcohol, 2-phenyl ethyl alcohol, geraniol and citronellol by spectrometry (UV, IR, $^1$H-NMR, $^{13}$ C-NMR) and enzymatic hydrolysis with $\beta$ - glucosidase. Monoterpene alcohols with a sterically hindered hydroxyl group, such as linalool, $\ell$-menthol and $\alpha$-terpineol were not used as acceptors in transglycosylation reaction.

• Applied Biological Chemistry
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• 제40권6호
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• pp.478-483
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• 1997

E. coli K-12 균주에서 ${\gamma}-Glutamylcysteine$ synthetase를 정제하고 효소적 방법에 의한 글루타치온 합성에 관련된 특성을 검사하였다. 정제한 효소의 활성은 L-glutamate의 농도가 60 mM 까지 증가와 더불어 증가하였으나, 60 mM L-cysteine 에서는 50% 그리고 45 mM glycine 에서는 40%의 효소활성이 감소되었다. 효소의 활성은 반응산물 중의 하나인 ADP 뿐만 아니라 환원형 글루타치온에 의해서 감소되었다. 그러므로 환원형 글루타치온 뿐만 아니라 glutathione synthetase의 기질인 glycine은 ${\gamma}-glutamylcysteine$ synthetase 활성을 저해하므로 글루타치온 생산을 위해서는 ${\gamma}-glutamylcysteine$ synthetase 반응과 glutathione synthetase의 두 분리된 반응으로 이루어진 생반응계를 고안하는 것이 바람직하다. 또한 글루타치온 합성반응으로 부터 생성되는 ADP는 ${\gamma}-glutamylcysteine$ synthetase의 활성을 감소시키므로 글루타치온 합성을 위해서 ATP 재생계의 도입이 필요하다.

• KSBB Journal
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• 제8권4호
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• pp.320-327
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• 1993

스티렌/아크렬 라텍스 폴리머를 폴리에릴렌이민으 로 표면처 리하여 얻은 PEI-microspheres는 그 표면 화학적 특성이 효소의 고정화에 적합하여 배당체의 합성반응에 서 필요로 하는 alginate-enclosed micro­s spheres biocatalyst를 제조할 수 있었고 라텍스 폴리머 표변에 형성된 폴리에틸렌이민 피막은 효소 부근에 친수성 분위기를 유지하여 높은 효소활성을 나 타내었을 뿐만 아니라, 생성된 배당체가 효소에 접 근하여 가수분해되는 반응을 억제하여 배당체의 수 율과 농도를 크게 증가시 켰으므로 alginate-en closed microspheres에 의한 배당체의 합성반응이 연속생산공정으로 연구개발 될 수 있다.