Oxidative Transformation of Dihydroflavonols and Flavan-3-ols by Anthocyanidin Synthase from .
Fiche publication
Date publication
février 2022
Journal
Molecules (Basel, Switzerland)
Auteurs
Membres identifiés du Cancéropôle Est :
Dr NEGRONI Luc
Tous les auteurs :
Zhang JR, Trossat-Magnin C, Bathany K, Negroni L, Delrot S, Chaudière J
Lien Pubmed
Résumé
Twelve polyphenols from three distinct families (dihydroflavonols, flavan-3-ols, and flavanones) were studied as potential substrates of anthocyanidin synthase from (ANS). Only flavan-3-ols of (2,3) configuration having either a catechol or gallol group on ring B are accepted as substrates. Only dihydroflavonols of (2,3) configuration are accepted as substrates, but a catechol or gallol group is not mandatory. Flavanones are not substrates of ANS. HPLC and MS/MS analyses of the enzymatic products showed that the ANS-catalyzed oxidative transformation of (+)-dihydroflavonols, such as dihydroquercetin, dihydrokaempferol and dihydromyricetin, leads only to the corresponding flavonols. Among the flavan-3-ols recognized as substrates, (+)-gallocatechin was only transformed into delphinidin by ANS, whereas (+)-catechin was transformed into three products, including two major products that were an ascorbate-cyanidin adduct and a dimer of oxidized catechin, and a minor product that was cyanidin. Data from real-time MS monitoring of the enzymatic transformation of (+)-catechin suggest that its products are all derived from the initial C-hydroxylation intermediate, i.e., a 3,3-gem-diol, and their most likely formation mechanism is discussed.
Mots clés
2-oxoglutarate, Vitis vinifera, anthocyanidin synthase, ascorbate, catechin, dihydroflavonol, flavanol, leucoanthocyanidin, mass spectrometry, structure-activity relationship
Référence
Molecules. 2022 Feb 3;27(3):