Synthesis of molecularly imprinted polymers using acrylamide‐β‐cyclodextrin as a cofunctional monomer for the specific capture of tea saponins from the defatted cake extract of Camellia oleifera

Abstract

Molecularly imprinted polymers were synthesized using mixed tea saponins as a template and acrylamide-β-cyclodextrin as a cofunctional monomer for the specific binding and purification of tea saponins from the defatted cake extract of Camellia oleifera. The adsorption properties of the prepared polymers were systematically evaluated including adsorption kinetics, adsorption isotherms, and selective recognition characteristics. It showed that the adsorption kinetics followed the pseudo first-order kinetic model (R = 0.995) with an equilibrium time of 3 h, adsorption isotherm data fitted well with the Langmuir-Freundlich model (R = 0.984) with an adsorption capacity of 14.23 mg/g. The relative selectivity coefficient (k´) in the presence of the analogues glycyrrhizic acid and glycyrrhetinic acid were 1.16 and 17.21, respectively. The performance of the molecularly imprinted polymers as solid-phase extraction materials was investigated and the results indicated that using acrylamide-β-cyclodextrin as a cofunctional monomer improved both the adsorption capacity and active sites stability of the imprinted polymers. The solid-phase extraction using the polymers as packing materials was subsequently applied for the separation of tea saponins in raw C. oleifera press extract, and targets were obtained with a purity reaching 89%.

Recent Advances of Molecularly Imprinted Polymers Based on Cyclodextrin

“…Guo et al. [ 20 ] prepared MIP with AA‐β‐CD and AA as bi‐functional monomers through free radical polymerization to capture tea saponins from the defatted cake extract of camellia oleifera. The specific recognition of template molecules mainly depended on the host‐gest inclusion of the AA‐β‐CD and the tea saponins, while MIP without CD recognized templates primarily through hydrogen bonding.…”

Green Aspects in Molecularly Imprinted Polymers by Biomass Waste Utilization

“…Cyclodextrins can be used directly to act as specific functional monomers in MIP preparation [ 120 , 121 , 122 ] or can be modified in order to enhance the interactions with the template molecule. Moreover, they can also be used as binary functional monomers in combination with other monomers [ 123 , 124 , 125 , 126 , 127 , 128 , 129 ]. A common modification used consists in the addition of acryloyl and allyl moieties [ 115 , 130 , 131 , 132 , 133 ].…”

Fe3O4@chitosan‐bound boric acid composite as pH‐responsive reusable adsorbent for selective recognition and capture of cis‐diol‐containing shikimic acid

“…Adsorption has been paid more attention in recent years owing to its flexibility of operation, fast adsorption rate and recyclability . Presently, natural polymers have attracted widespread interest as adsorbents (Figure ) due to their strong availability, economic and environmental benefits …”