title: Antioxidant and ion-induced gelation functions of pectins enabled by polyphenol conjugation.
abstract: The development of antioxidant polymers through the chemical conjugation of natural polyphenols onto polysaccharides has important applications in biomedical, pharmaceutical, food, and cosmetic fields. Due to their labile characteristics, the covalent conjugation of polyphenols while retaining antioxidant properties has been a challenging task. Herein, four structurally different polyphenols, three with and one without a catechol group, were conjugated onto pectin macromolecules via a simple and efficient preparation method involving epichlorohydrin chemistry. The conjugation reactions were confirmed by FT-IR and UV-vis characterization, and the free radical scavenging assay confirmed that the polyphenols maintained their antioxidant activity after the reaction. The conventional structure-antioxidant property relationship can be applied to the assay results, and hesperidin without a catechol group showed the lowest antioxidant capability. The coordination of multivalent metal ions with polyphenols enabled ionic crosslinking and the moduli of hydrogels depend on the type of polyphenols and their molecular interactions with metal ions. The simplicity of preparation and the resulting unique properties could make the pectin conjugates useful in a wide range of application areas.
authors.affiliation: Department of Chemical Engineering and Materials Science, Chung-Ang University, 221, Heukseok-dong, Dongjak-gu, Seoul, 156-756, Republic of Korea.
authors.forename: Soohwan
authors.initials: S
authors.lastname: Ahn
authors.affiliation: Department of Chemical Engineering and Materials Science, Chung-Ang University, 221, Heukseok-dong, Dongjak-gu, Seoul, 156-756, Republic of Korea.
authors.forename: Kantappa
authors.initials: K
authors.lastname: Halake
authors.affiliation: Department of Chemical Engineering and Materials Science, Chung-Ang University, 221, Heukseok-dong, Dongjak-gu, Seoul, 156-756, Republic of Korea. Electronic address: jong@cau.ac.kr.
authors.forename: Jonghwi
authors.initials: J
authors.lastname: Lee
mesh_terms: D004355:Drug Stability; D016166:Free Radical Scavengers / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D010368:Pectins / Q000737:chemistry*; D059808:Polyphenols / Q000737:chemistry*; D013696:Temperature; D014783:Viscosity
chemical_list: D016166:Free Radical Scavengers; D020100:Hydrogels; D059808:Polyphenols; D010368:Pectins
keywords: Antioxidant; Conjugation; Hydrogels; Metal ion binding; Pectin; Polyphenols