The adsorption of Naproxen enantiomers on the chiral stationary phase Whelk-O1 under reversed-phase conditions: The effect of buffer composition

Abstract

The adsorption of the Naproxen enantiomers on the chiral stationary phase (S,S)-Whelk-O1 from methanol-water 80:20 (v/v) solutions modified with the addition of acetic acid or an acetic acid-sodium acetate buffer was studied using elution chromatography. Adsorption was found to be best accounted for by a two-site model assuming different retention mechanisms for the two enantiomers. Under experimental conditions causing a considerable degree of solute dissociation, strong distortion of overloaded band profiles is observed. This phenomenon is explained by the superimposition of the adsorption and the dissociation equilibria. The effect of the buffer composition on the retention is discussed and the results compared with previous ones obtained with the same system. The proposed model explains all the principal features of the adsorption of Naproxen on Whelk-O1 that were found earlier. Moreover this model applies well in a wider range of buffer concentrations, encompassing both the eluents in which solute dissociation is suppressed and those in which dissociation is significant.

Enantioselective synthesis of (S)‐naproxen using immobilized lipase on chitosan beads

“…This fact has led to great efforts to develop efficient methods to obtain enantiomerically pure compounds in recent years. [3][4][5] Nonsteroid antiinflammatory drugs (NSAIDs) are rated as the top chiral drugs. (S)-naproxen is an important member of the family of 2-aryl propionic acid derivatives, which are widely used as NSAIDs for the treatment of arthritis and body pains.…”

Enantioresolution of Chiral Derivatives of Xanthones on (S,S)‐Whelk‐O1 and l‐Phenylglycine Stationary Phases and Chiral Recognition Mechanism by Docking Approach for (S,S)‐Whelk‐O1

“…16,22,54,55 Indeed, recent publications are devoted to the adsorption of naproxen on Whelk-O1 CSP under reversed-phase conditions, 56,57 concerning the effect of mobile phase 58 and buffer composition. 59 As a general rule, enantiomers that exhibit an H-bond acceptor and an aromatic moiety close to the stereogenic center tend to be well resolved on Whelk-O1 CSP. 16 L-Phenylglycine CSP has also been proven to be capable to operate not only under normal-phase elution conditions but also reversed-phase conditions.…”

“…However, the Whelk‐O1 CSP has also been reported to be useful in polar‐organic and reversed‐phase elution conditions, within a wide range of mobile phases . Indeed, recent publications are devoted to the adsorption of naproxen on Whelk‐O1 CSP under reversed‐phase conditions, concerning the effect of mobile phase and buffer composition . As a general rule, enantiomers that exhibit an H‐bond acceptor and an aromatic moiety close to the stereogenic center tend to be well resolved on Whelk‐O1 CSP .…”

A combined theoretical and experimental study for the chiral discrimination of naproxen enantiomers by molecular modeling and second-order standard addition method

“…8,9 With the development of modern analytical instruments, many separation techniques have been developed for chiral separation and analysis over the years, such as chromatography and capillary electrophoresis, with CDs and their derivatives as the chiral selector. [10][11][12][13] However, there are still challenges to develop real-time, low-cost, rapid, reliable and robust methods for assessing the enantiomeric composition in a pure form and in other matrices. Molecular uorescence is an attractive option, due to its simplicity, speediness, and high sensitivity.…”