title: Synthesis and structural characterization of oaklin-catechins.
abstract: Condensation reactions of procyanidin dimer B4 with two representative oak wood cinnamic aldehydes (coniferaldehyde and sinapaldehyde) were conducted in winelike model solutions. Coniferaldehyde led to the formation of guaiacylcatechin-pyrylium-catechin (GCP-catechin, 737 m/z), whereas sinapaldehyde led to the formation of syringylcatechin-pyrylium-catechin (SCP-catechin, 767 m/z). The former was also structurally characterized by 1D and 2D NMR, allowing an elucidation of the formation mechanism of these oaklin-catechin adducts and demonstrating the importance of procyanidins in the formation of colored compounds through the reaction with cinnamic aldehydes extracted from oaks during storage.
authors.affiliation: Departamento de Química, Faculdade de Ciências, Universidade do Porto, Centro de Investigação em Química, Rua do Campo Alegre 687, 4169-007 Porto, Portugal.
authors.forename: André
authors.initials: A
authors.lastname: Sousa
authors.forename: Ana
authors.initials: A
authors.lastname: Fernandes
authors.forename: Nuno
authors.initials: N
authors.lastname: Mateus
authors.forename: Victor
authors.initials: V
authors.lastname: De Freitas
mesh_terms: D000171:Acrolein / Q000031:analogs & derivatives / Q000737:chemistry; D002396:Catechols / Q000737:chemistry*; D010860:Pigments, Biological / Q000138:chemical synthesis*; D044945:Proanthocyanidins / Q000737:chemistry; D029963:Quercus; D014920:Wine / Q000032:analysis; D014934:Wood / Q000737:chemistry*
chemical_list: D002396:Catechols; D010860:Pigments, Biological; D044945:Proanthocyanidins; C075384:coniferaldehyde; C075386:sinapaldehyde; D000171:Acrolein; C034221:catechol