title: Liquid-phase method for peptide synthesis utilizing photolytic cleavage from a new o-nitrobenzoyl polyethylene glycol support.
abstract: Photolysis as a method for removal of a tert-butyloxycarbonyl-protected peptide possessing a free C-terminal carboxyl group from a polystyrene support in the solid-phase method of peptide synthesis was introduced by Rich, D. H. and Gurwara, S. K.((1975) J. Am. Chem. Soc. 97, 1575-1578). Using this basic concept we prepared a photosensitive 3-nitro-4-bromomethylbenzoyl polyethylene glycol support for use in the liquid-phase method of peptide synthesis. Photolytic cleavage of a protected tetrapeptide possessing a free C-terminal carboxyl group from the polyethylene glycol support resulted in a 98% yield compared with a 69% yield for the photolytic leavage from the polystyrene support. This application of photolysis as a cleavage method in liquid-phase peptide synthesis avoids the low yields and rather drastic conditons needed to remove a peptide attached directly to the poly-ethylene glycol support in the conventional liquid-phase method.
mesh_terms: D000409:Alanine; D005998:Glycine; D007202:Indicators and Reagents; D007700:Kinetics; D007930:Leucine; D008722:Methods; D009579:Nitrobenzoates; D010455:Peptides / Q000138:chemical synthesis*; D011092:Polyethylene Glycols; D014633:Valine
chemical_list: D007202:Indicators and Reagents; D009579:Nitrobenzoates; D010455:Peptides; D011092:Polyethylene Glycols; D007930:Leucine; D014633:Valine; D000409:Alanine; D005998:Glycine