Sugammadex analogue cyclodextrins as chiral selectors for enantioseparation of cathinone derivatives by capillary electrophoresis

The present contribution describes the application of three single-isomeric cyclodextrin derivatives for the first time - Sugammadex, Subetadex and Sualphadex as chiral selectors. Their recognition ability was investigated by means of chiral capillary electrophoresis, on a pool of cathinone and amphetamine deriva-tives. The selectors differ in cavity sizes and in the number of ionizable groups which evidently influenced their enantioselectivity performance. Their common feature is their high isomeric purity that enabled the detailed study of the molecular association between the cathinone guest and the cyclodextrin host at the atomic level. With the aid of enantiopure cathinone derivatives, the migration order could also be determined in capillary electrophoresis. As the result of the capillary electrophoresis screening, partial or baseline chiral separation of 19 cathinones and an amphetamine derivative could be achieved, and the systematic study was performed focusing on three different pH conditions pH = 7.0, pH = 5.0 and pH = 2.5 and several different selector concentrations. Among the tested derivatives Subetadex is the best performing chiral selector, especially under acidic pH values for separating enantiomers, proven not only by capillary electrophoresis but also by 1D and 2D NMR measurements.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This paper describes the application of three single-isomeric cyclodextrin derivatives, Sugammadex, Subetadex, and Sualphadex, as chiral selectors for the first time. Their recognition ability was investigated through chiral capillary electrophoresis on a pool of cathinone and amphetamine derivatives. The size of the cavity and the number of ionizable groups of the selectors influenced their enantioselectivity performance. Subetadex showed the best performance as a chiral selector under acidic pH values, as proven by capillary electrophoresis and NMR measurements.