• 약학회지
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• 제33권2호
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• pp.129-139
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• 1989

New diamide chiral stationary phases of four systematically substituted optically active N-(N-benzoyl-L-amino acid)-anilide synthesized from L-valine, L-leucine, L-isoleucine, and L-phenylalanine were described. The behaviors of these diamides as optically active stationary phases for the separation of N-trifluoroacetyl-D,L-amino acids were examined with respect to separation factors(${\alpha}$) and thermodynamic properties of interaction. The separation of twelve N-trifluoroacetyl-D,L-amino acid isopropyl esters were improved by the order of N-(N-benzoyl-L-leucyl)-anilide>N-(N-benzoyl-L-isoleucyl)-anilide>N-(N-benzoyl-L-valyl)-anilide>N-(N-benzoyl-L-phenylalanyl)-anilide. Eight amino acid derivatives with non-polar R-group and threonine, serine, aspartic acid, and glutamic acid enantiomers were separated on N-(N-benzoyl-L-leucyl)-anilide as chiral stationary phase with good separation factor between 1.07-1.25. The separation factors decreased with respect to increasing column temperature. Possible working temperature of diamide phase was between $130-190^{\circ}C$ for N-(N-benzoyl-L-phenylalanyl)-anilide and $130-180^{\circ}C$ for other three diamide phases. The differential Gibb's free energy (${\Delta}{\Delta}G$) of enantiomers was in the range of -100--180 cal/mol for ten amino acids and -40--60 cal/mol for alanine and aspartic acid.

• Archives of Pharmacal Research
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• 제23권6호
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• pp.568-573
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• 2000

A reversed-phase high-performance liquid chromatographic method was developed to determine the optical purity of bevantolol enantiomers. (S)-(-)-Menthyl chloroformate((-)-MCF), (S)-(-)-$\alpha$-methylbenzyl isocyanate((-)-MBIC) and 2,3,4,6-tetra-O-acetyl-$\beta$-D-glucopyranosyl isothiocyanate(GITC), which can react with the secondary amine group of bevantolol were investigated as chiral derivatization reagents. Among them indirect chiral HPLC method using CITC gave the best result. The derivatization proceeded quantitatively within 20 min at room temperature. Separation of the enantiomers as diastereomers was achieved by reversed-phase HPLC within 20min using ODS column. Different ratios of (S)-(-)-bevantolol and (R)-(+)-bevantolol were prepared. Enantiomeric separation of these mixtures took place on a chiralcel OD column or, after derivatization with GITC, on a ODS column. No racemization was found during the experiment. This method allowed determination of 0.05% of either enantiomer in the presence of its stereoisomer and method validation showed adequete linearity over the required range.

• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1775-1779
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• 2006

A liquid chromatographic chiral stationary phase (CSP) based on (+)-(18-crown-6)-2,3,11,12-tetracarboxilic acid without extra free aminopropyl groups on silica surface has been demonstrated to be quite effective for the resolution of various $\beta$-amino acids. The retention factors ($k_1$) for the resolution of $\beta$-amino acids on the CSP were quite large and the large retention factors might be quite attractive along with the reasonable separation factors ($\alpha$) for preparative scale enantioselective chromatography. The large retention factors on the CSP were found to be reduced effectively by adding ammonium ion to mobile phase without sacrificing the chiral recognition efficiency of the CSP. Consequently, the CSP is also quite applicable for use in analytical enantioselective chromatography.

• Archives of Pharmacal Research
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• 제23권1호
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• pp.26-30
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• 2000

The enantiomers of the bronchodilator terbutaline were separated by reversed-phase high performance liquid chromatograhy after derivatization with 2,3,4,6-tetra-O-acetyl-\beta-D-glucopyranosyl isothiocyanate(GITC) reagent. The derivatization proceeded quantitatively within 1 h at room temperature. The corresponding diastereomeric thiourea derivatives were well resolved on an ODS column with acetonitrile-acetate buffer as a mobile phase. Elution orders of the diastereomers were confirmed by derivatization of R-(-)-terbutaline and S-(+)-terbutaline which were collected by semi-preparative chiral HPLC using Sumichiral OA-4700 column. The native fluorescence of terbutaline was quenched by derivatization with GITC. The detection limit was 25ng when monitored at UV 278 nm.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.506-510
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• 2003

TMB 크로마토그래피의 물질수지식으로부터 SMB 크로마토그래피의 디자인 파라미터들을 계산할 수 있으며, 이를 이용하여 6 칼럼 SMB 크로마토그래피 장치를 디자인하였다. SMB 크로마토그래피 장치는 4개의 multi position rotary valve를 사용하여 연속적으로 각 칼럼으로의 유로를 제어할 수 있으며, 효율적인 SMB 크로마토그래피 장치를 구현할 수 있다. 또한 회분식 실험으로부터 얻어진 $m_2$, $m_3$ diagram으로부터 SMB 크로마토그래피의 조작에 필요한 파라미터들을 계산할 수 있었다.

• Natural Product Sciences
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• 제6권1호
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• pp.20-24
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• 2000

The enantiomers of higenamine were directly separated by high performance liquid chromatography using a chiral stationary phase and detected by UV. The R- and S-isomers of higenamine were eluted at the retention time of 22 min and 27 min, respectively. Higenamine was determined to be present as R-(+)-enantiomer not only in the embryo of Nelumbo nucifera, from which the separation of R-(+)-higenamine was reported, but also in various Aconite roots, from which higenamine was separated as optically inert racemic mixtures.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.400.3-401
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• 2002

Levosulpiride is the levo-enantiomer from of racemic sulpride. abenzamide derivative selectively inhibition doparninergic D2 receptos at the trigger zone both in the central nervous system and in the gastrointestinal tract. We report a rapid and sensitive HPLC method using reverse phase C 18 column with fluorescence detection for separation and quantitation of levosulpiride in plasma. Tiapride was used as an internal standard. After adding an internal standard. levosulpiride in 800 ${\mu}l$ of plasma was extracted under basic conditions with ethyl acetate and methylene chloride. (omitted)

• Korean Membrane Journal
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• 제1권1호
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• pp.38-42
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• 1999

Membrane technology can be applied in two ways to produce pure enantiomers. In one case a membrane separation process can be cmbined with an enantiospecific reaction to obtain so-called 'en-antiospecific membrane reacto' These systems are useful to carry out asymmetric synthesis or kinetic resolution and simulatneously separate the produced enantiomer. As for general membrane reactors the result is a more compact system with a higher conversion: in fact removal of a product drives equilibrium-limited reactions towards completion. The other way to apply membrane technology to chiral production is the use of intrinsically enantioselective membranes that are able to distinguish between two isomers favouring preferential transport of only one isomer in absence of reaction. In this paper the current development of chiral membrane processes will be discussed.

• Bulletin of the Korean Chemical Society
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• 제26권8호
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• pp.1153-1163
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• 2005

Crown ether-based HPLC chiral stationary phases (CSPs) have been successfully utilized in the resolution of various racemic compounds containing a primary amino group. Especially, CSPs based on chiral crown ethers incorporating chiral binaphthyl unit or tartaric acid unit and based on phenolic pseudo chiral crown ethers have shown high chiral recognition efficiency. In this account paper, a review on the development of crown etherbased HPLC CSPs, their structural characteristics and applications to the resolution of racemic compounds including chiral drugs containing a primary or secondary amino group with the variation of the type and the content of mobile phase components and with the variation of the column temperature is presented.

• 한국막학회:학술대회논문집
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• 한국막학회 1999년도 The 7th Summer Workshop of the Membrane Society of Korea
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• pp.31-34
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• 1999

Membrane technology can be applied in two ways to produce pure enantiomers. In one case, a membrane separation process can be combined with an enantiospecific reaction to obtain so-called 'enantiospecific membrane reactor'. These systems are useful to carry out asymmetric synthesis or kinetic resolution and simultaneously separate the produced enantiomer. As for general membrane reactors, the result is a were compact system with a higher conversion; in fact, removal of a product drives equilibrium-limited reactions towards completion. The other way to apply membrane technology to chiral production is the use of intrinsically enantioselective membranes that are able to distinguish between two isomers favouring preperential transport of only one isomer in absence of reaction. In This paper, the current development of chiral membrane processes will be discussed.