Synthesis and evaluation of chloro SPIRO and amino SPIRO supports: Novel hydrophilic cross-linked polystyrene polymers for solid phase peptide synthesis

Abstract

Synthesis of a novel, beaded, hydrophobic/hydrophilic balanced and chemically robust chloro SPIRO polymer matrix consisting of styrene and 4-Chloromethyl styrene (VBC) as backbone and 3,9-Divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane as cross-linking units is demonstrated here. The suspension polymerisation technique was preferred to achieve complete monomer to polymer conversion as well as to attain spherical beaded form. Two different cross-linking densities (2 and 4 mol.%) of polymer supports were synthesized and the composition of the functional bearing site VBC was fixed as 3 mol.% for both supports. The integrity of chloro SPIRO polymer formed was verified by Fourier transform infrared spectroscopy and scanning electron microscopy analysis. Chloro SPIRO resin was subjected to Gabriel Phthalimide reaction to form amino SPIRO resin. Chemical integrity of chloro SPIRO resin was tested in different standard solid phase peptide synthetic conditions and swelling capacity was studied using amino SPIRO resin in different polar solvent conditions. The synthetic capacity of novel amino SPIRO polymer matrix was evaluated by synthesising classically challenging acyl carrier protein peptide by Fmoc strategy. The purity of peptide was checked by high performance liquid chromatography and mass by matrix assisted laser desorption.