APPLICATION OF SULFATED CYCLODEXTRINS TO CHIRAL SEPARATIONS BY CAPILLARY ZONE ELECTROPHORESIS

Mixtures of randomly substituted sulfated cyclodextrins (degree of sub stitution, similar to 7-10) were successfully used as chiral additives for the enantioseparation of 56 compounds of pharmaceutical interest, including anesthetics, antiarrhythmics, antidepressants, anticonvulsa nts, antihistamines, antihypertensives, antimalarials, relaxants, and bronchodilators. The separations were accomplished at pH 3.8, with the anode at the detector end of the column, Under these conditions, in w hich electroosmotic now is directed toward the injection end of the co lumn and the electrophoretic mobility of the negatively charged cyclod extrin is toward the detector, none of the analytes reached the detect or in the absence of the sulfated cyclodextrin. Most (40) of the succe ssfully resolved enantiomers contained basic functionality and a stere ogenic carbon, However, the versatility of this sulfated cyclodextrin additive was also demonstrated by the fact that three atropisomers, 1, 1'-binaphthyl-2,2'-diyl hydrogen phosphate, 1,1'-binaphthyl-2,2'-diol, and Troger's base, and several neutral analytes were also successfull y enantioresolved under these conditions. The separation mechanism see ms to involve inclusion complexation.