• 제목/요약/키워드: Decarboxylation

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CoA Transferase and Malonyl-CoA Decarboxylase Activity of Malonate Decarboxylase from Acinetobacter calcoaceticus

  • Byun, Hye-Sin;Kim, Yu-Sam
    • BMB Reports
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    • 제30권4호
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    • pp.246-252
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    • 1997
  • Malonate decarboxylase from Acinetobacter calcoaceticus is shown to have malonyl-CoA: acetate CoA transferase. acetyl-CoA: malonate CoA transferase, and malonyl-CoA decarboxylase activity. These enzyme activities were elucidated by isotope exchange reactions. The enzyme modified by N-ethylmaleimide completely lost its malonate decarboxylase activity, whereas it still kept CoA transferases and malonyl-CoA decarboxylase activities. The existence of CoA transferases and malonyl-CoA decarboxylase activity is clear, but their physiological significance is obscure. The catalytic reactions for two eoA transfers and malonyl-CoA decarboxylation proceed via a cyclic mechanism, which is through two covalent intermediates, enzyme-Smalonyl and enzyme-S-acetyL proposed for malonate decarboxylation of the enzyme.

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tert.-Butyl ${\beta}$-(o-tolyl)-perpropionate 치환체들의 합성 (Syntheses of Substituted tert.-Butyl(o-tolyl)-perpropionates)

  • 한치선
    • 대한화학회지
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    • 제8권4호
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    • pp.153-157
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    • 1964
  • Chloromethylation, malonic ester 합성법 및 decarboxylation에 의한 중간체들을 거친 tert.-butyl ${\beta}$-(o-tolyl)-perpropionate 치환체들의 합성을 기술하였다. 심하지 않은 치환기효과를 나타내는 bromo-, chloro- 및 methyl- 기를 가진 중간체들은 좋은 수율로 얻어져서 목적한 바 과산화 ester들을 얻었으나 nitro기를 가진 중간체는 극히 적은 수율로 얻어졌고 한편 센 electron donating effect를 나타내는 group로 치환된 toluene들의 chloromethylation은 polymerize하는 결과를 가져왔다.

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탄산칼슘계 재료를 잔골재로 사용한 모르타르의 고온수열 후 중량변화 (Weight change after high-temperature hydrothermal heat of mortar using calcium carbonate-based material as fine aggregate)

  • 신종현;김해나;홍상훈;정의인;김봉주
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2022년도 가을 학술논문 발표대회
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    • pp.75-76
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    • 2022
  • In the event of a fire in the lower space, a high temperature of 1000℃ or more and an explosive fire may occur due to the closed structural features and combustible materials. On the other hand, more than 90% of oyster shells are made of CaCO3, and when heated to about 700℃ or higher, CaO and CO2 is generated due to decarboxylation reaction. In this study, we try to infer the amount generated by CO2 changing the weight of mortar using oyster shells as fine aggregates after heating. in conclusion It is considered that the smaller the particle, the greater the decarboxylation reaction and the greater the weight change.

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Photocyclization Reactions of ($\omega$-Phthalimidoalkoxy)acetic Acids via Sequential Single Electron Transfer-Decarboxylation Pathways

  • Yoon, Ung-Chan;Lee, Chan-Woo;Oh, Sun-Wha;Oh, Sun-Wha;Hyun Jin kim;Lee, Sang-Jin
    • Journal of Photoscience
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    • 제7권4호
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    • pp.143-148
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    • 2000
  • Studies have been conducted to explore single electron transfer(SET) promoted photocyclization of ($\omega$-phthalimidoalkoxy)acetic acids(alkoxy=ethoxy, n-propoxy and n-butyloxy). Photocyclizations occur in methanol or acetone in high yields to produce cyclized products in which phthalimide carbonyl carbon is bonded to the carbon of side chain in place of the carboxylic group. These photocyclizations are thought to proceed through pathways involving intramolecular SET from oxygen in the $\alpha$-carboxymethoxy groups to the singlet excited state phthalimide moieties followed by decarboxylation of the intermediate $\alpha$-carboxymethoxy cation fadicals and cyclizations by radical coupling. The photocyclizations occur ca. three times faster in both methanol or acetone with one equivalent of sodium hydroxide added to the reactions and occur slower in acetone than in methanol. The efficient and regiselective cyclization reactions observed for photolyses in methanol represent synthetically useful processes for construction of heterocyclic compounds.

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Enterobacter aerogenes에 의한 수소 생산 초기 단계인 포메이트 탈카복시 반응 연구 (Formate Decarboxylation: Initial Step for Hydrogen Production by Enterobacter aerogenes)

  • 최진영;조영충;안익성
    • 공업화학
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    • 제20권4호
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    • pp.449-452
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    • 2009
  • 철,셀레늄,그리고 몰리브데늄이 결여되어 있는 최소배지는 Escherichia coli MC4100의 혐기성 배양에서의 수소생산을 억제하였다. 철, 셀레늄, 그리고 몰리브데늄은 대장균과 Enterobacter 모두의 formate dehydrogenase ($FDH_{II}$) 효소의 보조인자로 알려져 있다.그러므로 이러한 미량성분들이 최소배지에 결여되어 있을 때는 $FDH_{II}$를 통한 수소생산이 대장균 뿐만 아니라 E. aerogenes에서도 저해될 것이다. 이러한 성분들이 부족할 때 E. aerogenes 413에 의한 수소 생산은 지연되었다.그러므로,E. aerogenes에 의한 수소 생산은 NADH의 재산화가 아닌 포메이트 탈카복시 반응에 의해서 시작된다고 사료된다.

有機할로겐化合物과 KF 과의 反應 (第2報) 有機요-드酸, 沃化物 及 多鹽素化有機酸, 에스텔의 雙合, 弗化 及 脫炭酸 反應에 關하여 (Reaction of Potassium Fluoride with Orgarnic Halogen Compound-II. Dimerization, Fluorination, and Decarboxylation of Organic Iodo acids, Iodides, and Polychlorinated Acid Ester)

  • 김유선
    • 대한화학회지
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    • 제8권4호
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    • pp.135-141
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    • 1964
  • 아밀아이오다이드를 디메칠홀움아마이드 存在下에서 弗化加里와 低溫反應시켜 본 結果 弗化物과 데칸을 生成하였음. ${\alpha}$, ${\beta}$-디크로로-${\beta}$-페닐-푸로피온酸과 같은 多鹽素化物은 ${\alpha}$-크로로스타이렌, 弗化스타이렌 及 弗化酸을 生成하였음. 이 酸의 에칠에스텔은 弗化物을 生成하지 않고 各種 쌍合物의 混合物을 얻었음. 디부롬스타이렌은 부롬스타이렌과 弗化物을 生成하고 沃度를 含有한 有機酸, 메-타요드벤젠익酸은 有機酸의 鹽과 微量의 쌍合物을 生成하였음. 메타요드토류엔 及 1-아미노-4-요-드-2-메칠벤젠과 같은 沃化物은 弗化物은 弗化加里에 對하여 反應을 나타내지 않었음. 本報에는 各 反應條件과 弗化反應, 脫炭酸反應 及 쌍合反應에 關하여 論義하였음.

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