Nonaqueous Capillary Electrophoretic Enantioseparation of Water Insoluble Tröger's Base Derivatives Using β‐Cyclodextrin as Chiral Selector

Abstract

Racemic mixtures of six Tröger's base derivatives were separated by chiral nonaqueous capillary electrophoresis. The separation protocol was optimized first for suitable solvents. Then the applicability of various salts dissolved in organic solvents and their mixtures was evaluated. As chiral selectors β-cyclodextrin and heptakis(2,6-di-O-methyl)-β-cyclodextrin at various concentrations were used. The best enantioselectivity for the studied analytes was obtained utilizing formamide as organic nonaqueous solvent containing a mixture of sodium citrate and tris(hydroxymethyl)aminomethane acetate as electrolytes, and β-cyclodextrin as chiral additive. The experimental results demonstrated the feasibility of nonaqueous capillary electrophoresis for enantioseparation of Tröger's base derivatives. This technique represents a suitable alternative to more commonly used capillary electrophoresis in aqueous environment.

The influence of the substituent position in monocarboxymethyl-γ-cyclodextrins on enantioselectivity in capillary electrophoresis

“…Some of these analytes, namely, primaquine , TB1 and TB2 have been separated previously utilizing a mixture of carboxymethylated α‐CDs, and TB1 employing a mixture of highly sulfated α‐CDs . Racemic mixtures of diperodon , mefloquine , primaquine , TB1 , TB2 , and tryptophan methyl ester have been successfully separated by native β‐CD and carboxymethylated β‐CDs. Tryptophan methyl ester enantiomers have also been resolved by heptakis(2,6‐di‐ O ‐methyl)‐β‐CD in CE mode.…”

Chiral Separations by Capillary Electrophoresis and related Techniques with Different Chiral Selectors: A Review

“…Among all CDs, β-CD is the most preferred CS agent because it is versatile and can be easily derivatized by reacting with different compounds [138][139][140][141]. Although γ-CD has the largest gap, the presence of an odd number of glucose rings reduces the symmetry of the gap, thereby increasing the dissolving power of the β-CD [142].…”

Application of cyclodextrins in chiral capillary electrophoresis

“…Jasmonic acid [203]; norephedrine [128]; ANDA-CC-penicillamine [204]; trimipramine [205]; tryptophan [206]; vincamine, vinpocetine, and vincadifformine [122]; four basic compounds [58]; five N,S exo-heterodisubstituted O-carborane ligands [207]; Tic-hydantoin derivatives [208]; binaphthol and its mono derivatives [174,209]; acyclic nucleoside phosphonate [210] ␤-CD Amisulpride [211]; DTAF-aspartic acid [212]; baclofen [138]; catechin, chlorpheniramine, and promethazine [213]; ephedrine [130]; epicatechin [214]; fluvastatin [215]; ANSA-fucose and FMOC-pipecolic acid [216]; metoprolol [217]; binaphthol and its mono derivatives [209]; 6,6 -dibromo-1,1 -binaphthyl-2,2 -diol [218]; norephedrine [128]; penicillamine [202]; ANDA-CC-penicillamine [204]; 1,4-bis(9-O-quininyl)phthalazine [219]; dioxopromethazine [220]; propranolol [221]; salsolinol and its derivatives [136]; NBD-F-serine [194]; Tröger's base derivatives [222,223]; DNS-tyrosine and DNS-threonine [195]; vincamine, vinpocetine, and vincadifformine [122]; zopiclone [224]; ␤-agonists [225][226][227]; nine amino acids [228]; three amino acids and 13 DNS amino acids ...…”