title: Enzymatic synthesis, structural characterization and antioxidant capacity assessment of a new lipophilic malvidin-3-glucoside-oleic acid conjugate.
abstract: The chemical modification of anthocyanins (water-soluble pigments) into more lipophilic compounds is very important to expand their application in the food, medical and cosmetic industries. In this work, the synthesis of a pure malvidin-3-glucoside-oleic acid ester derivative was achieved by enzymatic catalysis. This approach allowed us to synthesize a novel compound, malvidin-3-O-(6''-oleoyl)glucoside (Mv3glc-OA), which was structurally characterized by mass spectrometry and for the first time by NMR spectroscopy. The enzymatic reaction revealed to be regioselective giving only one ester product. Antioxidant features of the malvidin-3-glucoside lipophilic derivative by means of DPPH, FRAP and lipid peroxidation assays were assessed, which confirmed that the structural modification of the genuine malvidin-3-glucoside into a more lipophilic compound did not compromise its antioxidant potential and protected more effectively a lipidic substrate from oxidation, which is an important insight for future technological applications.
authors.affiliation: REQUIMTE/LAQV, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal. luis.cruz@fc.up.pt.
authors.forename: Luis
authors.initials: L
authors.lastname: Cruz
authors.forename: Iva
authors.initials: I
authors.lastname: Fernandes
authors.forename: Marta
authors.initials: M
authors.lastname: Guimarães
authors.forename: Victor
authors.initials: V
authors.lastname: de Freitas
authors.forename: Nuno
authors.initials: N
authors.lastname: Mateus
mesh_terms: D000872:Anthocyanins / Q000096:biosynthesis / Q000737:chemistry*; D000975:Antioxidants / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D008401:Gas Chromatography-Mass Spectrometry; D005960:Glucosides / Q000096:biosynthesis / Q000737:chemistry*; D015227:Lipid Peroxidation; D009682:Magnetic Resonance Spectroscopy; D009829:Oleic Acids / Q000096:biosynthesis / Q000737:chemistry*; D014920:Wine / Q000032:analysis
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D005960:Glucosides; D009829:Oleic Acids; C458419:malvidin-3-glucoside