title: Synthesis of organosoluble chitosan derivatives with polyphenolic side chains.
abstract: A one-pot synthesis was used to produce chitosan derivatives with polyphenolic side chains via a regioselective phenolic coupling reaction. Under Mannich reaction conditions, treatment of chitosan with formaldehyde and methyl 2,4-dihydroxybenzoate gave N-(2,6-dihydroxy-3-methoxycarbonylphenyl)methylated chitosan in good yield (87%). Formation of a CC bond occurred regioselectively at the C(3) position of methyl 2,4-dihydroxybenzoate. Chitosan derivatives having various phenolic compounds as a side chain were easily synthesized in a similar manner. The chitosan derivatives showed good biodegradability and improved their solubility in methanol (9.8mg mL(-1)) and 2-methoxyethanol (> 10mg mL(-1)). The UV protection provided by the derivatives with phenolic benzophenone side chain was evaluated using UV spectra of polyethylene terephthalate and poly(vinyl butyral-co-vinyl alcohol-co-vinyl acetate) films coated with the derivatives and the derivatives absorbed effectively in the UV-A region (<60%). Self-aggregation of the chitosan derivatives with the phenolic side chain was observed by using a fluorescent probe in aqueous solution.
authors.affiliation: Research Center for Bioscience and Technology, Tottori University, Koyama, Tottori 680-8550, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Morimoto
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nakajima
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ishikura
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Shigemasa
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Ifuku
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Saimoto
mesh_terms: D048271:Chitosan / Q000138:chemical synthesis* / Q000737:chemistry*; D062385:Hydroxybenzoates / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D062385:Hydroxybenzoates; D048271:Chitosan; C017616:phenolic acid