• 제목/요약/키워드: enantioselectivity

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유기용매에서 효소반응을 통한 라세믹 $\alpha$-Methylbenzylamine 광학적 분할의 최적화 (Optimization of the Optical Resolution of Racemic $\alpha$-Methylbenzylamine Catalyzed by Enzymatic Reaction in Organic Media)

  • 강병영;김병기
    • KSBB Journal
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    • 제9권3호
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    • pp.306-311
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    • 1994

  • 유기용매상에서 Bacillus licheniformis에서 생산되는 protease를 이용하여 라세믹 ${\alpha}$-methylbenzy lamine의 광학분함을 행하였다. 이 반응은 아설 제 공자로 활성 에스대르를 샤용하여 라서l믹 아민을 광 학선택적으로 아마드로 변환시킨다. 이 반응의 반응 속도와 광학선택성을 증가시켜주기 위해 효소를 완 충액에 녹여 pH를 맞춘 후에 동결건조시키거나, 동결건조시 염이나 lyoprotectants를 첨가시키는 방 법, 적당한 유기용매의 선정, 에스테르 구조의 디자 인 등의 방법을 사용하였다. 그 결과. 30배의 초기 반응속도의 증가 및 12배의 광학선택성이 증가하는 결과를 보였다.

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Enantiomeric Separation of Amino Acids Using N-alkyl-L-proline Coated Stationary Phase

  • Lee Sun Haing;Oh Tae Sub;Lee Hae Woon
    • Bulletin of the Korean Chemical Society
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    • 제13권3호
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    • pp.285-289
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    • 1992

  • Enantiomeric separation of underivatized amino acids using N-alkyl-L-proline (octyl, dodecyl or hexadecyl) coated HPLC has been accomplished. The anchoring N-alkyl groups of L-proline provides a permanent adsorption of there solving chiral agent on the hydrophobic interface layer of a reversed phase. The factors controlling retention and enantioselectivity such as the Cu(II) concentration, pH of the eluent, the type and concentration of organic modifier in the hydroorganic eluent, and extent of coating were examined. The elution orders between D- and L-amino acids were consistent, L-forms eluting first, except histidine and asparagine. The extremely high enantioselectivity $(\alpha$ upto 13 for proline) is observed. The retention mechanism for the chiral separation can be illustrated by a complexation and hydrophobic interaction.

  • https://doi.org/10.5012/bkcs.1992.13.3.285 인용 PDF

Chiral Recognition Models of Enantiomeric Separation on Cyclodextrin Chiral Staionary Phases

  • 이선행;김병학;이영철
    • Bulletin of the Korean Chemical Society
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    • 제16권4호
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    • pp.305-309
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    • 1995

  • The enantiomeric separation of several amino acid derivatives by reversed-phase liquid chromatography using two (R)-and (S)-naphthylethylcarbamate-β-cyclodextrin(NEC-β-CD) bonded stationary phases was studied to illustrate the chiral recognition model of the enantiomeric separation. The retention and enantioselectivity of the chiral separations with (R)-and (S)-NEC-β-CD bonded phases were compared with similar separations with the native β-CD stationary phases. Especially, the enantioselectivity and elution orders between the derivatized amino acid enantiomers are carefully examined. These results can be illustrated by the chiral recognition models involving inclusion complexation, π-π interaction, and/or hydrophobic interaction. Inclusion complexation and hydrophobic interaction of the naphthyl group of the NEC moiety seem to be major chiral recognition components in the enantiomeric separation of 2,4-dinitrophenyl amino acids and dabsyl amino acids on (R)-and (S)-NEC-β-CD columns. For dansyl amino acids, only the inclusion complexation is the dominant factor. Three different chiral recognition models containing π-π interaction, inclusion complexation and hydrogen bonding were proposed for the separation of the 3,5-dinitrobenzoyl amino acid enantiomers, depending on the size and shape of amino acids.

  • https://doi.org/10.5012/bkcs.1995.16.4.305 인용 PDF