Polyoxyethylene, polystyrene grafted

E Bayer, M Dengler. B Hemmasi. Peptide synthesis on the new polyoxyethylene-polystyrene graft copolymer, synthesis of insulin B21.30. btt J Pept Prot Res 25, 178, 1985. 

Several groups have attempted the anchoring of ketone catalysts for use in combination with Oxone (404-407). One of the incentives for anchoring the catalyst is that the most suitable ketone, 1,1,1-trifluoroacetone, is highly volatile. A solid-bound, nonvolatile ketone therefore offers obvious handling and cost advantages. In one approach, 4-(trifluoroacetyl)benzoic acid was anchored to a graft copolymer of polystyrene and polyoxyethylene (17a) (406) alternatively, aliphatic ketones were covalently bound to silica (17b) (405, 407). 

Most synthetic methods for the generation of peptide libraries have been derived from various multiple parallel peptide synthesis techniques developed since 1984.bs-i l Consequently, the sohd supports used for hbrary synthesis are essentially the same as those used for multiple peptide synthesis. Standard divinylbenzene cross-linked polystyrene resins are typically used for hbraries that are cleaved from the resin and screened in solution.P Polyoxyethylene-grafted polystyrene resins,f l or acrylamide-polyoxyethylene copolymers, P on the other hand, are the sohd supports of choice for the synthesis of resin-bound peptide hbraries screened in sohd-phase binding assays.P Such resins are compatible with both organic solvents used for peptide synthesis, as well as aqueous buffers used in the bioassays. Various segmental supports previously employed for multiple peptide syntheses have also been utilized for the synthesis of peptide libraries, including polypropylene pins, PI cotton,t cellulose membrane,and glass shdes.P ... 

The graft copolymer thus obtained was extracted with cyclohexane three times, each for 24 hours, so as to remove unreacted polystyrene. After vacuum drying, it was extracted three times (each lasting 24 hrs) with 20% aqueous solution of ethyl alcohol, in order to remove polyoxyethylene homopolymer. Phenyl content of the graft copolymer and the extracts were measured by a 730 Ultraviolet Spectrophotometer. IR spectra were obtained by a Perkin-Elmer 580B Spectrophometer. 

---