Enantioselective sorption of some chiral carboxylic acids by various cyclodextrin-grafted iron oxide magnetic nanoparticles

Abstract

A new enantioselective sorption approach to chiral carboxylic acid molecules such as (R)-(-)-N-(3,5-dinitrobenzoyl)phenylglycine (R)-(-)DNBPG, (S)-(+)-N-(3,5-dinitrobenzoyl)phenylglycine (S)-(+)DNBPG, (R)-(+)-N-(1-phenylethyl)phthalamic acid (R)-(+)PEPA and (S)-()-N-(1-phenylethyl)phthalamic acid (S)-(-)PEP A regarding their complexation with three diversely functionalized beta-cyclodextrin grafted iron oxide nanoparticles in the aqueous phase, was developed. The sorption efficiencies of these carboxylic acids were carried out by high-performance liquid chromatography (HPLC) with an Ace 5 C18 column. The effects of temperatures on the sorption were also investigated. The results showed that the ether functionalized derivative of beta-cyclodextrin Al-CD-MNPs has a specific affinity for (R)-(-)DNBPG at 30 degrees C and pH 7.0. The amine functionalized derivative of beta-cyclodextrin Am-CD-MNPs has a greater affinity towards not only (S)-()DNBPG, but also (R)-(+)PEPA compared with their other isomers, which are the (R)-isomer of DNBPG and the (S)-isomer of PEPA at 30 degrees C and pH 7.0. In addition, although amide functionalized derivatives of beta-cyclodextrin (Amd-CD-MNPs) have an affinity towards both isomers of some chiral carboxylic acids; no selective affinity was observed at 30 degrees C and pH 7.0. (C) 2013 Elsevier Ltd. All rights reserved.