Evidence of Diketopiperazine and Oxazolone Structures for HA b₂+ Ion

Citations Over TimeTop 10% of 2009 papers

Abstract

Peptide fragmentation can lead to an oxazolone or diketopiperazine b(2)(+) ion structure. IRMPD spectroscopy combined with computational modeling and gas-phase H/D exchange was used to study the structure of the b(2)(+) ion from protonated HAAAA. The experimental spectrum of the b(2)(+) ion matches both the experimental spectrum for the protonated cyclic dipeptide HA (a commercial diketopiperazine) and the theoretical spectrum for a diketopiperazine protonated at the imidazole pi nitrogen. A characteristic band at 1875 cm(-1) and increased abundance of the peaks at 1619 and 1683 cm(-1) indicate a second population corresponding to an oxazolone species. H/D exchange also shows a mixture of two populations consistent with a mixture of b(2)(+) ion diketopiperazine and oxazolone structures.

Related Papers

• → Recent Advances in Oxazolone Chemistry(1965)32 cited
• → Structure of a peptide oxazolone: 2-(1'-benzyloxycarbonylamino-1'-methylethyl)-4,4-dimethyl-5-oxazolone(1980)12 cited
• → Synthesis, Characterization and Insilco Study of New 1,3-Oxazolone-5-(4-Cl)-one and - Oxazolone-5-(4-NO₂)-one Derivatives(2019)3 cited
• → The Use of 4-Cyanoaminomethylene-2-phenyl-5(4h)-oxazolone in the Synthesis of Some Heteroarylaminomethylene Substituted 5(4H)-Oxazolones(1996)3 cited
• → 2‐Phenyl‐5‐Oxazolone(2003)1 cited