title: New pseudopeptidic cross-linker containing urea bonds: study of its degradation routes in aqueous media using capillary electrophoresis-mass spectrometry.
abstract: An accelerated degradation study has been performed on TLT, a pseudopeptide that includes esterified tyrosine and lysine linked by urea bonds, as well as on their derivatives, i.e., a dimethacrylic cross-linker (DMTLT) and a poly(dimethylacrylamide) cross-linked with DMTLT. The monitoring and analytical characterization has been carried out by capillary electrophoresis-mass spectrometry (CE-MS), using ion trap and time-of-flight MS analyzers. Several degradative species have been identified, and a kinetic analysis of the variation of their concentration with time has been obtained. During the initial stages of degradation, there is a competition between hydrolysis of the ester groups and cyclization by nucleophilic attack of the NHs of the urea groups to the carbonyl ester group. At higher degradation time (weeks or months), evidences of backbone breakdown, including urea hydrolysis, have been found.
authors.affiliation: Institute of Polymer Science and Technology, CSIC, Juan de la Cierva 3, 28006 Madrid, Spain.
authors.forename: Paloma
authors.initials: P
authors.lastname: Pérez
authors.forename: Carolina
authors.initials: C
authors.lastname: Simó
authors.forename: Christian
authors.initials: C
authors.lastname: Neusüss
authors.forename: Matthias
authors.initials: M
authors.lastname: Pelzing
authors.forename: Julio
authors.initials: J
authors.lastname: San Roman
authors.forename: Alejandro
authors.initials: A
authors.lastname: Cifuentes
authors.forename: Alberto
authors.initials: A
authors.lastname: Gallardo
mesh_terms: D003432:Cross-Linking Reagents / Q000494:pharmacology*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D046911:Macromolecular Substances / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods*; D008956:Models, Chemical; D009842:Oligopeptides / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D013696:Temperature; D014508:Urea / Q000031:analogs & derivatives* / Q000737:chemistry*
chemical_list: D003432:Cross-Linking Reagents; D046911:Macromolecular Substances; D009842:Oligopeptides; D010455:Peptides; D011108:Polymers; C511859:tyrosine-lysine-tyrosine pseudotripeptide; D014508:Urea