title: Access to tetra-N-acetyl-chitopentaose by chemical N-acetylation of glucosamine pentamer.
abstract: Nowadays, the easy access of tetra-N-acetyl-chitopentaose and its counterparts is highly interesting since such chemical compounds are precursors of biological signal molecules with a strong agro-economic impact. The chemical synthesis of tetra-N-acetyl-chitopentaose by controlled N-acetylation of the glucosamine pentamer hydrochloride under mild conditions is described herein. A systematic study on the influence of the different parameters involved in this reaction, such as the solvent, the acetylating agent, and the base used for the deprotonation of ammonium groups of the starting material was carried out. The characterization of final reaction products by HPLC and MALDI-TOF mass spectrometry showed that each of these parameters affects differently the acetylation reaction. Whereas the solvent plays an important role in the N- or O-acetylation selectivity, the acetylating agent and the base were found to influence both the degree of N-acetylation and the distribution of the partially N-acetylated derivatives in the product mixtures. Based on these results, optimized reaction conditions have been established allowing tetra-N-acetyl-chitopentaose to be synthesized in a one-pot deprotonation/N-acetylation of the glucosamine pentamer hydrochloride in a moderate yield (ca 30%).
authors.affiliation: Ingénierie des Matériaux Polymères, UMR CNRS 5223, Université Claude Bernard Lyon 1, Domaine Scientifique de la Doua, Bâtiment POLYTECH, 15 bd André Latarjet, 69622 Villeurbanne Cedex, France.
authors.forename: Maher
authors.initials: M
authors.lastname: Abla
authors.forename: Laurence
authors.initials: L
authors.lastname: Marmuse
authors.forename: Frédéric
authors.initials: F
authors.lastname: Delolme
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Vors
authors.forename: Catherine
authors.initials: C
authors.lastname: Ladavière
authors.forename: Stéphane
authors.initials: S
authors.lastname: Trombotto
mesh_terms: D000107:Acetylation; D005944:Glucosamine / Q000737:chemistry*; D009844:Oligosaccharides / Q000737:chemistry*; D010429:Pentoses / Q000737:chemistry*; D058105:Polymerization; D012997:Solvents / Q000737:chemistry
chemical_list: D009844:Oligosaccharides; D010429:Pentoses; D012997:Solvents; D005944:Glucosamine
keywords: Acetylation; Chitooligosaccharide; Chitopentaose; Chitosan oligomer; MALDI-TOF mass spectrometry