Chiral separations of 1,3,4-thia- and 1,3,4-selenadiazine derivatives by use of non-aqueous capillary electrophoresis

Our aim was to establish suitable conditions for the chiral separation of 1 2 1.3,4-thia- and 1,3,4-selenadiazine derivatives; some of them were identi fied in screening tests as potential antituberculotics, To overcome possibl e problems: with the water insolubility of most analytes, we profited by th e advantages of non-aqueous capillary electrophoresis, Methanol, formamide, and a mixture of formamide with acetonitrile (1:2, v/v) were used as separ ation media. Hydroxyethyl-, hydroxypropyl-, and methyl-beta -cyclodextrin w ere applied as chiral selectors in concentrations of 200 mM. Besides the ef fect of these different electrophoretic media and selectors, Lye also inves tigated the consequences of using different electrolytes (25 mM ammonium ac etate/1 M acetic acid anti 25 mM citric acid/12.5 mM TRIS). Distinct differ ences of the separation fiictors in the different separation media were obs erved. Depending on structure characteristics of the analytes, we establish ed clear classifications to these cyclodextrins (CD), which were most appro priate for the separation of the enantiomers of the particular analytes. (C ) 2001 Elsevier Science B,V. All rights reserved.