title: Incorporation of azaglutamine residues into peptides synthesised by the ultra-high load solid (gel)-phase technique.
abstract: The solid (gel)-phase peptide synthesis of peptides, each containing an azaglutamine residue, has been examined. Procedures using various mono-, di- and tripeptide and carbazate fragments containing or relating to an azaglutamine (1) residue have been evaluated. N-Activation of the amino-terminus of a resin-bound peptide with bis-(2,4-dinitrophenyl)carbonate (2) yielded the terminal isocyanate species, which reacted with protected carbazates to give resin-bound protected peptides containing the aza-residue. By contrast, coupling of activated amino-acid derivates to the free amino-group of a resin-bound peptide with an aza-residue at the N-terminus was a slow and unsatisfactory process. It is concluded that the route yielding the best results involves the reaction of a protected amino-acyl carbazate to a resin-bound isocyanate-activated peptide.
authors: School of Chemistry, University of Birmingham, Edgbaston, Great Britain.
authors: C J
authors: CJ
authors: Gray
authors: M
authors: M
authors: Quibell
authors: N
authors: N
authors: Baggett
authors: T
authors: T
authors: Hammerle
mesh_terms: D000595:Amino Acid Sequence; D002254:Carbonates / Q000737:chemistry; D002625:Chemistry, Organic / Q000379:methods; D002851:Chromatography, High Pressure Liquid; D003485:Cyanates / Q000737:chemistry; D004136:Dinitrobenzenes / Q000737:chemistry; D005973:Glutamine / Q000031:analogs & derivatives* / Q000737:chemistry; D006834:Hydrazines / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis*; D012116:Resins, Plant / Q000737:chemistry
chemical_list: D002254:Carbonates; D003485:Cyanates; D004136:Dinitrobenzenes; D006834:Hydrazines; D009842:Oligopeptides; D012116:Resins, Plant; D005973:Glutamine; C079223:azaglutamine; C029424:hydrazine; C010877:carbazic acid; C079224:bis(2,4-dinitrophenyl)carbonate