Enantio-selective molecularly imprinted β-resorcylic acid-modified resin for chiral separation of cathinone

Abstract

This article explains the development of an enantioselective durable material that is based on a cross-linked β-resorcylic acid-resorcinol-formaldehyde copolymer for the chiral recognition of S-cathinone (CTN) and the effective enantioseparation of the (±)-CTN racemic mixture. In a first step, a polymerizable S-CTN-β-resorcylic acid amide was produced and characterized through elemental analysis, Fourier transform infrared (FTIR), and nuclear magnetic resonance (NMR) spectroscopy. Thereafter, the obtained chiral amide was copolymerized with resorcinol-formaldehyde by means of acidic condensation polymerization, and the resulting polymeric resin was treated with sodium hydroxide and subsequently HCl to remove the S-CTN template molecules. The molecularly imprinted polymer that was formed was characterized through scanning electron microscopy, FTIR, and energy dispersive X-ray spectroscopy and then tested for selective extraction of S-CTN. Adsorption was carried out in line with the Langmuir model, and the findings showed that the maximum capacity was 205 ± 2 mg/g at a pH of 7. Moreover, the optical separation was performed utilizing a column, with results showing approximate enantiomeric excess values of 65% and 95% inside the supernatant and eluant solutions, respectively, for S- and R-CTN.