Optical resolution and mechanism using enantioselective cellulose, sodium alginate and hydroxypropyl‐β‐cyclodextrin membranes

Abstract

Chiral solid membranes of cellulose, sodium alginate, and hydroxypropyl-β-cyclodextrin were prepared for chiral dialysis separations. After optimizing the membrane material concentrations, the membrane preparation conditions and the feed concentrations, enantiomeric excesses of 89.1%, 42.6%, and 59.1% were obtained for mandelic acid on the cellulose membrane, p-hydroxy phenylglycine on the sodium alginate membrane, and p-hydroxy phenylglycine on the hydroxypropyl-β-cyclodextrin membrane, respectively. To study the optical resolution mechanism, chiral discrimination by membrane adsorption, solid phase extraction, membrane chromatography, high-pressure liquid chromatography ultrafiltration were performed. All of the experimental results showed that the first adsorbed enantiomer was not the enantiomer that first permeated the membrane. The crystal structures of mandelic acid and p-hydroxy phenylglycine are the racematic compounds. We suggest that the chiral separation mechanism of the solid membrane is "adsorption - association - diffusion," which is able to explain the optical resolution of the enantioselective membrane. This is also the first report in which solid membranes of sodium alginate and hydroxypropyl-β-cyclodextrin were used in the chiral separation of p-hydroxy phenylglycine.

Microreaction and membrane technologies for continuous single-enantiomer production: A review

“…[109,110] These membranes can be divided into two basics groups: i) liquid membranes [104,[111][112][113][114] and ii) solid membranes. [115][116][117] The separation principle is based on specific interactions of atoms and/or groups of atoms of an enantiomer molecule with the surface atoms or groups of atoms at the membrane surface. These interactions account for variations in the transport rate of a given enantiomer through the membrane.…”

“…Another example of an enantioselective solid membrane is a blend of cellulose, sodium alginate, and hydroxypropyl-β-cyclodextrin. This membrane has reached an enantiomeric excess of more than 89% in the separation of p-hydroxy phenylglycine [117] as chirally active centers formed in spaces between helical conformations of cellulose and sodium alginate. In those spaces, hydroxypropyl-β-cyclodextrin was attached to the macrocyclic ring, creating a chiral recognition surface on the membrane.…”

Combining Cellulose and Cyclodextrins: Fascinating Designs for Materials and Pharmaceutics

“…The functionalization of cellulose and cellulose derivatives by grafting with CDs has contributed for the development of new materials with improved properties and added value, in different areas, involving the development of new materials. These include the removal of pollutants (Nthunya et al, 2017 ), such as metal ions (Wan et al, 2004 ; Zhou et al, 2011 ) dyes (Ogawa et al, 2011 ; Xiong and Shao, 2011 ; Ghemati and Aliouche, 2014 ; Song et al, 2017 ), polycyclic aromatic compounds (Liu et al, 2015b ; Zhang et al, 2015 ; Yuan et al, 2017a ), and drugs (Celebioglu et al, 2014 ; Orelma et al, 2018 ) from wastewaters, and enantiomeric separation (Xiao and Chung, 2007 ; Xiao et al, 2007 ; Zhou et al, 2009 ; Zhang et al, 2012 ; Yuan et al, 2017b ). Also contemplated, are membrane processes (Andrade et al, 2015 ; Sulaiman et al, 2017 ) and food packaging.…”

Chiral Separation in Preparative Scale: A Brief Overview of Membranes as Tools for Enantiomeric Separation

“…Membranes of cellulose, sodium alginate, and hydroxypropyl-beta-cyclodextrin were prepared for the chiral separation of mandelic acid (10) and p-hydroxy phenylglycine (11) [131]. The membrane material concentrations, the preparation conditions and feed concentrations were optimized to obtain good enantioseparations.…”

“…For p-hydroxy phenylglycine, enantiomeric excesses of 42.6%, and 59.1% were obtained on the sodium alginate membrane, and on the hydroxypropyl-β-cyclodextrin membrane, respectively. It was the first report in which solid membranes of sodium alginate and hydroxypropyl-β-cyclodextrin were applied for the chiral separation of p-hydroxy phenylglycine [131].…”