title: Enzymatic cross-linking of carboxymethylpullulan grafted with ferulic acid.
abstract: Carboxymethylpullulan (CMP) has been modified in a two-step grafting reaction of ferulic acid (FA). Acid adipic dihydrazyde (ADH) was first reacted with FA activated with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC). Then the product of this first reaction was reacted with CMP (activated with EDC). Grafted polysaccharides structure was confirmed by FTIR and (1)H NMR spectroscopy. Analyses by size-exclusion chromatography (SEC) coupling on-line with a multi-angle light scattering detector (MALS), a viscometer and a differential refractive index detector (DRI) (SEC/MALS/DRI/Visco) showed that associations between FA moieties occurred due to hydrophobic interactions. The grafting rates of FA were determined by the Folin-Ciocalteu method and were found between 1.0% and 11.2% (mol/mol anhydroglucose unit). The CMP-FA were then enzymatically cross-linked with laccase from Pleurotus ostreatus. The crosslinking reactions were followed by rheological measurements, demonstrating the influence of laccase concentration on kinetics. Elastic modulus and swelling rates of hydrogels depends on FA content only for low values.
authors.affiliation: Normandie Université, France; Université de Rouen, Laboratoire Polymères Biopolymères Surfaces, F-76821 Mont Saint Aignan, France; CNRS UMR 6270 & FR3038, F-76821 Mont Saint Aignan, France. Electronic address: virginie.dulong@univ-rouen.fr.
authors.forename: Virginie
authors.initials: V
authors.lastname: Dulong
authors.affiliation: Normandie Université, France; Université de Rouen, Laboratoire Polymères Biopolymères Surfaces, F-76821 Mont Saint Aignan, France; CNRS UMR 6270 & FR3038, F-76821 Mont Saint Aignan, France.
authors.forename: Ahdi
authors.initials: A
authors.lastname: Hadrich
authors.affiliation: Normandie Université, France; Université de Rouen, Laboratoire Polymères Biopolymères Surfaces, F-76821 Mont Saint Aignan, France; CNRS UMR 6270 & FR3038, F-76821 Mont Saint Aignan, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Picton
authors.affiliation: Normandie Université, France; Université de Rouen, Laboratoire Polymères Biopolymères Surfaces, F-76821 Mont Saint Aignan, France; CNRS UMR 6270 & FR3038, F-76821 Mont Saint Aignan, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Le Cerf
mesh_terms: D003373:Coumaric Acids / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D055119:Elastic Modulus; D005936:Glucans / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D042845:Laccase / Q000737:chemistry*; D012212:Rheology
chemical_list: D003373:Coumaric Acids; D003432:Cross-Linking Reagents; D005936:Glucans; D020100:Hydrogels; C410955:carboxymethylpullulan; C004999:ferulic acid; D042845:Laccase
keywords: Enzymatic cross-linking; Laccase; Pullulan; Rheology