Structural and chromatic characterization of a new Malvidin 3-glucoside–vanillyl–catechin pigment

A new pigment, resulting from the reaction between malvidin 3-glucoside and catechin in the presence of vanillin, was detected in a model solution. This newly formed anthocyanin-aryl-flavanol adduct was structurally characterized by 1D and 2D NMR and mass spectrometry, and its chromatic characteristics were studied by UV–Vis techniques. The new pigment was shown to have a wavelength of maximum absorption in the visible region (λmax) of 549 nm, conferring on it a purple colour, and a molar extinction coefficient value (ε) of 12,247 l · mol−1 · cm−1.