CLEAR:  A Novel Family of Highly Cross-Linked Polymeric Supports for Solid-Phase Peptide Synthesis^1,2

Abstract

Cross-Linked Ethoxylate Acrylate Resin (CLEAR) supports were prepared by radical copolymerization, either in the bulk or suspension mode, of the branched cross-linker trimethylolpropane ethoxylate (14/3 EO/OH) triacrylate (1) with one or more of allylamine (2), 2-aminoethyl methacrylate‚HCl (3), poly(ethylene glycol-400) dimethacrylate (4), poly(ethylene glycol) ethyl ether methacrylate (5), and trimethylolpropane trimethacrylate (6). The resultant highly cross-linked copolymers by the bulk procedures were ground and sieved to particles, whereas the suspension polymerization procedure gave highly cross-linked spherical beaded supports. CLEAR polymeric supports showed excellent swelling properties in an unusually broad range of solvents, including water, alcohols, tetrahydrofuran, dichloromethane, and N,N-dimethylformamide. To demonstrate their usefulness for peptide synthesis, CLEAR supports were derivatized with an "internal reference" amino acid [norleucine] and a handle valeric acid] and were tested for both batchwise and continuous-flow solidphase syntheses of challenging peptides such as acyl carrier protein (65-74), retro-acyl carrier protein (74-65), and the 17-peptide human gastrin-I. Comparisons to commercially available supports, e.g., polystyrene, Pepsyn K, Polyhipe, PEG-PS, TentaGel, and PEGA were also carried out. CLEAR supports are entirely stable under standard conditions of peptide synthesis but are in some cases labile to certain strong bases.

Equilibrium and non-equilibrium structures in complex food systems

“…Therefore, other strategies may be appealing to stabilize HIPE in foods. Taking inspiration from the synthetic analogues, where poly-HIPE, have been widely developed and employed, HIPE where both the continuous and dispersed phase are polymerised by a liquid HIPE containing polymerisable units in both phases (Cameron & Barbetta, 2000;Kempe & Barany, 1996), or solidification of either phase or both phases in Food HIPE appear as a viable and promising route. This could be achieved, for example, by using crystallisable oils for the hydrophobic phase and a gelling water-pectin or watercarrageenan solutions for the hydrophilic phase.…”

Co-polymerization of Acrylates

“…A number of cross-linkers are used for the synthesis of such products. During the last decade polymer supports with hydrophilic cross-linking agents have received much attention [53]. The hydrophilicity and flexibility imparted by the cross-linking agent improved the salvation characteristics and enhanced the reactivity of the polymer-bound functional groups [54].…”

ULTRAMINE: A High‐Capacity Polyethylene–Imine‐Based Polymer and Its Application as a Scavenger Resin

“…The modified polystyrene supports have all been successfully employed for solidphase synthesis [6] and include poly(ethylene glycol)-polystyrene (PEG-PS), [7] tentagel graft resin, [8] poly(ethylene glycol) (meth)acrylate cross-linked polystyrene, [9] poly(ethylene oxide)-polystyrene (PEO-PS), [10] and JandaJel . [11] The favorable properties of these resins led to a second generation of more polar resins including polyamides, [12] poly(ethylene glycol) polyacrylamide (PEGA), [13] poly(oxyethylene)/ poly(oxypropylene) copolymer (POEPOP), [14] superpermeable organic combinatorial chemistry resin (SPOCC), [15] cross-linked ethoxylate acrylate resin (CLEAR), [16] and glycerol dimethacrylate/polymethylmethacrylate copolymer (GDMA-PMMA); [17] these resins contain no polystyrene and present excellent swelling properties both in nonpolar and in protic and aprotic polar solvents.…”