HPLC of fluoroquinolone antibacterials using chiral stationary phase based on enantiomeric (3,3'-diphenyl-1,1'-binaphthyl)-20-crown-6.
ABSTRACT A residual silanol group-protecting chiral stationary phase (CSP) based on optically active (3,3'-diphenyl-1,1'-binaphthyl)-20-crown-6 was successfully applied to the resolution of fluoroquinolone compounds including gemifloxacin mesylate. The chiral recognition ability of the residual silanol group-protecting CSP was generally greater than that of the residual silanol group-containing CSP. From these results, it was concluded that the simple protection of the residual silanol groups of the latter CSP with lipophilic n-octyl groups can improve its chiral recognition ability for the resolution of racemic fluoroquinolone compounds. The chromatographic resolution behaviors were investigated as a function of the content and type of organic and acidic modifiers and the ammonium acetate concentration in aqueous mobile phase and the column temperature. Especially, the addition of ammonium acetate to the mobile phase was found to be a quite effective means of reducing the enantiomer retentions without sacrificing the chiral recognition efficiency of the CSP.
- SourceAvailable from: Myung Ho HyunBulletin- Korean Chemical Society 01/2012; 33(10). · 0.84 Impact Factor
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ABSTRACT: Two chiral stationary phases (CSPs) based on (3,3'-diphenyl-1,1'-binaphthyl)-20-crown-6 bonded covalently to silica gel were applied for the first time to the resolution of racemic vigabatrin and its analogue -amino acids and the resolution results were compared to those on the commercially available Crownpak CR(+) based on (3,3'-diphenyl-1,1'-binaphthyl)-20-crown-6 coated dynamically onto octadecylsilica gel. While vigabatrin was not resolved at all on Crownpak CR(+), it was resolved quite well on the two CSPs. Among four vigabatrin analogue -amino acids, only two were resolved on Crownpak CR(+), but three were resolved on the CSP (CSP 1) containing residual silanol groups and all of four were resolved on the CSP (CSP 2) containing residual silanol group-protecting n-octyl groups. The improved lipophilicity in CSP 2 was proposed to be responsible for its superiority to CSP 1 for the resolution of vigabatrin and analogue -amino acids. In addition, the composition of aqueous mobile phase was found to affect the chiral recognition behaviors for the resolution of vigabatrin and analogue -amino acids on CSP 2.Bulletin- Korean Chemical Society 01/2011; 32(spc8). · 0.84 Impact Factor
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ABSTRACT: Mexiletine, an effective class IB antiarrhythmic agent, and its analogs were resolved on three different crown ether-based chiral stationary phases (CSPs), one (CSP ) of which is based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid and the other two (CSP and CSP ) are based on (3,3'-diphenyl-1,1'-binaphthyl)-20-crown-6. Mexiletine was resolved with a resolution (RS ) of greater than 1.00 on CSP and CSP containing residual silanol group-protecting n-octyl groups on the silica surface, but with a resolution (RS ) of less than 1.00 on CSP . The chromatographic behaviors for the resolution of mexiletine analogs containing a substituted phenyl group at the chiral center on the three CSPs were quite dependent on the phenoxy group of analytes. Namely, mexiletine analogs containing 2,6-dimethylphenoxy, 3,4-dimethylphenoxy, 3-methylphenoxy, 4-methylphenoxy, and a simple phenoxy group were resolved very well on the three CSPs even though the chiral recognition efficiencies vary with the CSPs. However, mexiletine analogs containing 2-methylphenoxy group were not resolved at all or only slightly resolved. Among the three CSPs, CSP was found to show the highest chiral recognition efficiencies for the resolution of mexiletine and its analogs, especially in terms of resolution (RS ). Chirality 00:000-000, 2014. © 2014 Wiley Periodicals, Inc.Chirality 03/2014; · 1.72 Impact Factor