• 제목/요약/키워드: hydroxycarboxylic acids

검색결과 10건 처리시간 0.022초

Preparation of enantiomerically pure (R)-3-hydroxybutyrate

  • 이영;이상엽
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2000년도 춘계학술발표대회
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    • pp.579-582
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    • 2000

  • Enantiomerically pure hydroxycarboxylic acids have great potential as chiral building blocks in fine chemicals due to their easily modificable two functional groups. Microbial polyhydroxyalkanoates (PHAs) can have more than one hundred of hydroxycarboxylic acids as monomeric constituents by growing cells under various conditions. All of the monomeric constituents are enantiomerically pure in (R)-conformation if there is a chiral center. Therefore, efficient production of enantiomerically pure hydroxycarboxylic acids by degrading PHAs is possible. In this presentation, we report on the development of a novel method for the preparation of (R)-hydroxybutyric acid by in vivo depolymerization of Polyhydroxybutyrae.

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Chiral Derivatization of Hydroxycarboxylic Acids Using 2,4,6-Trichlorobenzoyl Chloride as a Highly Efficient Regioselective Esterification Reagent for Gas Chromatography-Mass Spectrometry

  • Park, Jeong Hyeok;Han, Sang Yun
    • Mass Spectrometry Letters
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    • 제11권4호
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    • pp.103-107
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    • 2020

  • We report the application of 2,4,6-trichlorobenzoyl chloride (often referred to as Yamaguchi esterification reagent) for the selective derivatization of the carboxylic group for GC-MS with the sample preparation method optimized for GC-MS analysis. The reagent was shown to be capable of selectively turning the carboxylic group into a reaction center, i.e., anhydride, of which the further reaction was directed to a near complete formation of required esters by unique steric and electronic effects of the reagent. Using the developed method, the chiral separation of hydroxycarboxylic acids by GC-MS using non-chiral columns was successfully demonstrated.

  • https://doi.org/10.5478/MSL.2020.11.4.103 인용 PDF KSCI HTML

Sequential Copolypeptides (Ⅲ). Synthesis and Characterization of Poly ($\gamma$-benzyl-L-glutamyl-$\gamma$-benzyl-L-glutamyl-glycine)

  • Choi, Sang-Up;Kang, Joon-Kil
    • Bulletin of the Korean Chemical Society
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    • 제1권3호
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    • pp.78-82
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    • 1980

  • Solutions of $Cd^{2+}$, $Co^{2+}$ and $Ni^{2+}$ were mixed with the solutions of hydroxycarboxylic acids such as salicylic, lactic and mandelic acids in the presence of cation exchange resin at room temperature. The distribution ratios of the metal ions between resin and solution were measured, using radioactive metal ions as tracer. From the observed variation of the distribution ratios with the acid anion concentrations, it was concluded that $Cd^{2+}$, $Co^{2+}$ and $Ni^{2+}$ formed the one-to-one complexes with salicylate, lactate and mandelate ions in aqueous, 20 % ethanol-water and 20 % acetone-water solutions. The results of the present study indicated that the relative stabilities of the metal-acid complexes in solution increased in the order: $Cd^{2+}$ <$Co^{2+}$ <$Ni^{2+}$ complexes. Salicylate

  • https://doi.org/10.5012/bkcs.1980.1.3.78 인용 PDF

Complexes of Polyvalent Metal Ions (Ⅶ). Complexes of Cadmium, Cobalt and Nickel with Hydroxycarboxylic Acids in Aqueous, Ethanol-Water and Acetone-Water Solutions$^*$

  • Park, Joon-W.;Mukherjee, C.
    • Bulletin of the Korean Chemical Society
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    • 제1권3호
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    • pp.105-109
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    • 1980

  • A general spectroscopic method is described for studies on the complex formation between metal ions and ligands, and is applied to $Cu^{2+}$ and $Ca^{2+}$binding to glycosaminoglycans. The order of binding constants for both ions is heparin >dermatan sulfate >chondroitin sulfate. The electrostatic forces are shown to be the predominant factor in the interaction. The 2- to 3-fold higher affinity for $Cu^{2+}$ than for $Ca^{2+}$ is obtained for heparin and dermatan sulfate, but little difference for chondroitin sulfate. These results are explained as chelation of both carboxyl and sulfate groups to $Cu^{2+}$ in former cases. The difference of binding constants among glycosaminoglycans is related to proposed various biological functions of the biopolymers.

  • https://doi.org/10.5012/bkcs.1980.1.3.105 인용 PDF

Inducible System을 이용한 재조합 대장균으로부터 광학적으로 순수한 [R]-3-Hydroxybutyric acid 생산 (Production of Enantiomerically Pure [R]-3-Hydroxybutyric acid by Metabolically Engineered Escherichia coli with Inducible System)

  • 이영;최종일;이상엽
    • KSBB Journal
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    • 제19권4호
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    • pp.327-330
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    • 2004

  • Inducible system을 이용하여 (R)-hydroxybutyric acid (R3HB)를 생산하는 재조합 대장균을 개발하였다. Ralstonia eutropha에서 유래한 PHB depolymerase 유전자를 inducible promoter에 의하여 발현되게 만들고, PHB 생합성 유전자가 있는 vector에 cloning하였다. PHB 생합성 유전자와 depolymerase 유전자를 가지고 있는 재조합 대장균을 배양하여 먼저 PHB를 축적시킨 후에 depolymerase를 발현시켜 배지 내로 분비된 R3HB를 확인하였다. 그 결과 축적된 PHB의 대부분은 발현된 depolymerase에 의하여 분해되었으며, depolymerase의 발현 이후에도 재조합 대장균은 PHB를 축적하고 분해하여 R3HB의 농도는 배양시간에 따라 증가하였다. 이러한 결과는 inducible depolymerase를 갖는 재조합 대장균을 이용하여 높은 농도의 R3IB를 얻을 수 있다는 것을 보여준다.

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