• Proceedings of the PSK Conference
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• 2002.10a
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• pp.398.1-398.1
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• 2002

A new chiral derivatization agent with sugar moiety. 2, 3.4, 6-tetra-O-acetyl-D-galactopyranosyl isothiocyanate (GATC) was synthesized. Several $\beta$-blockers were investigated for the possible separation of the enantiomers by reversed-phase HPLC after derivatization with this new chiral derivatization agent (GATC). GATC was reacted readily with $\beta$-blockers at room temperature and the reaction mixture could directly be injected into the HPLC system. (omitted)

• Analytical Science and Technology
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• v.24 no.5
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• pp.360-367
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• 2011

Optical purities of 10 commercialized naproxens prepared from eight Korean drug companies were examined by an optimized chiral HPLC condition. The Chiralcel OD-H column and ChiralHyun-LE(S)-1 column were used as chiral stationary phases and the mixed eluent of hexane/isopropanol/acetic acid as 100:2.85:0.1 was used as a mobile phase for effective enantioseparation. Optical purity values of most samples were higher than 97 percents, only one of them was about 95 percents. The average relative standard deviation of them appeared very small (0.034%).

• Bulletin of the Korean Chemical Society
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• v.20 no.11
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• pp.1309-1312
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• 1999

Two chiral stationary phases (CSPs) derived from two diastereomers consisting of (R)- or(S)-α-naphthylethylamine and (S)-naproxen were found to show different chromatographic behaviors in resolving N-(3,5-dinitrobenzoyl)-α-arylalkylamines and N-(3,5-dinitrobenzoyl)-α- or β-amino amides and esters. From the different chromatographic resolution behaviors on the two CSPs, the chiral recognition is proposed to be controlled mainly by the (R)- or (S)-α-naphthylethylamine part of the CSP. In contrast, the (S)-naproxen part of the two CSPs is proposed to exert some subordinate effects on the chiral recognition.

• Analytical Science and Technology
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• v.34 no.1
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• pp.9-16
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• 2021

In the group of commonly prescribed β-blocker drugs, one of the enantiomers is generally relatively more active than the others. This study aims to develop a technique for the chiral analysis of select β-blockers based on proton nuclear magnetic resonance (1H-NMR) spectrometry. (S)-2-Tert-butyl-2-methyl-1,3-benzodioxole-4-carboxylic acid ((S)-TBMB) was synthesized and utilized as a chiral derivatizing agent. Pure β-blocker enantiomers were isolated from racemates by semi-preparative liquid chromatography prior to derivatization. The reaction time and concentration of (S)-TBMB were controlled to improve the derivatization procedure. No racemization was found during the analysis. High-performance liquid chromatography (HPLC) analysis was also performed for comparative purposes. High agreement between the NMR and HPLC methods was achieved in the determination of (R)-metoprolol in a standard solution of the (S) isomer.

• Analytical Science and Technology
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• v.36 no.4
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• pp.143-151
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• 2023

Considering the greater role of α-amino acids in our daily lives, the enantiomer resolution of seven α-amino acids derivatized with fluorogenic reagent (4-fluoro-7-nitro-2,1,3-benzoxadiazole, NBD-F) by chiral HPLC on amylose or cellulose trisphenylcarbamate derived chiral stationary phases (CSPs) under simultaneous ultraviolet (UV) and fluorescence (FL) detection was performed. The degree of enantioseparation and resolution was affected by nature and selector backbones of the CSPs as well as the kind of amino acids. Baseline enantiomer separation and resolutions were observed for the enantiomers of all analytes as NBD derivatives especially on coated type amylose tris(3,5-dimethylphenylcarbamate) derived CSPs (Chiralpak AD-H and Lux Amylose-1). The other CSPs also showed good enantioselectivity except for the CSPs (Chiralpak IB, Chiralcel OD-H and Lux Cellulose-1) having cellulose tris(3,5-dimethylphenylcarbamate) as chiral selectors. The developed analytical chiral method was applied to determine the enantiomeric purity of seven commercially available L-α-amino acids and the impurities as D-forms were found to be in the range 0.08-0.87 %, respectively. The intra- and interday accuracy and precision assays showed high accuracy and precision of the developed analytical method. This chiral HPLC method for the enantiomer resolution of amino acids using fluorescent derivatization could be useful for the determination of enantiomeric purity of pharmaceuticals and biological study for amino acid type compounds among chiral drugs.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.165-166
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• 2002

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.2186-2188
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• 2014

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.399.1-399.1
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• 2002

The chiral stationary phase derived from (＋) (18-crown-6)-2.3, 11.12-tetracarboxylic acid (18-C-6- TA) as a chiral selector has been employed for resolution of several $\alpha$-amino acids in HPLC. In a quest for the origin of chiral recognition of $\alpha$-amino acids in the presence of 18-C-6- T, A, as a chiral selector, these interactions responsible for the differential affinities shown toward enantioners were investigated by NNR spectroscopy. (omitted)

• Archives of Pharmacal Research
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• v.23 no.5
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• pp.441-445
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• 2000

Achiral-chiral column switching HPLC assay was developed to allow the separation and quantification of the enantiomers of terbutaline in human plasma by means of fluorescence detection. Plasma samples were prepared by solid-phase extraction with sep-pak silica, followed by HPLC assay. The enantiomers of terbutaline and the internal standard were separated from the biological matrix on a silica column, and the two enantiomers were resolved and quantified on a Sumichiral OA-4900 column. The two columns were connected by a switching valve equipped with silica trap column, The trap column was used to concentrate the terbutaline in the eluent from the achiral column before back flushing onto the chiral phase. For each enantiomers, the assay was linear between 2.5-125 ng/$m\ell$ (r=0.9999) and detection limit was 1.0 ng/$m\ell$ .

• Archives of Pharmacal Research
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• v.26 no.2
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• pp.114-119
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• 2003

A high performance liquid chromatographic (HPLC) method was developed for the qualitative and quantitative determination of benzophenanthridine alkaloids from the methanol extracts of Hylomecon hylomeconoides and H. vernale (Papaveraceae). Achiral and chiral methods were adapted for the separation of 6-methoxydihydrosanguinarine (1), 6-acetonyldihydrosanguinarine (2) and dihydrosanguinarine (3). The achiral reversed phase HPLC method made it possible the simultaneous separation and determination of 1, 2 and 3 within 20 min on ODS column using acetonitrile-phosphate buffer (50 mM, pH 7.0) (50 : 50, v/v). The separation and determination of 1 and 2 enantiomers was available using chiral columns. The same amount of (+) and (-)-enantiomers of 1 was found from the methanol extract of specimen, indicated that 1 could be the artifact produced by the reaction of sanguinarine with methanol. H. hylomeconoides showed higher level of 1 and 3 in compared with H. vernale, especially in root samples permitting the possibility of chemical discrimination between two species.