A theoretical interpretation of the color of two classes of pyranoanthocyanins

• Tipo: Artigo em Revista Científica Internacional
• Data: 2010

Autores

Alexandre R F Carvalho (Autor) Outra; Joana Oliveira (Autor) FCUP; Victor de Freitas (Autor) FCUP; Nuno Mateus (Autor) FCUP; Andre Melo (Autor) FCUP

Revista

Título: Journal of Molecular Structure: THEOCHEM

Vol. 948

Páginas: 61-64

ISSN: 0166-1280

Editora: Elsevier B.V.

Indexação

ISI Web of Knowledge - 12 Citações

Scopus - 12 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-003-6MW

DOI: 10.1016/j.theochem.2010.02.020

Abstract (EN): Anthocyanins are natural pigments that present a characteristic red color at low pH (<2). Anthocyanin-pyruvic acid adducts, commonly referred to as vitisins, are anthocyanin derivatives usually found in red wines. Looking at the two-dimensional structures, vitisins apparently have a greater conjugation system than anthocyanins. Following the common conjugation rules, making the chromophore more conjugated increases the value of lambda(max), and vitisins should have a longer lambda(max) than anthocyanins. However, they have a surprising lower lambda(max), presenting an orange color, under the same pH conditions. Another class of anthocyanin-derived pigments, portisins have the expected relative behaviour with a longer lambda(max) than anthocyanins. In this work, a quantum study on molecular models of pigment models was carried out. The results obtained enabled to present a putative explanation of the color change in these series.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 4