The Visible Flavonoids or Anthocyanins: From Research to Applications

Abstract

Anthocyanins are polyphenolic pigments responsible for most of the color diversity found in plants. Here the in vivo color expression and the stability of anthocyanins are interpreted by extrapolation of the results acquired in vitro with model solutions of pigments obtained through plant extraction or laboratorial synthesis. Behavior of anthocyanins is explained in terms of molecular interactions of the chromophore units with parts of the pigments themselves and/or with some constituents of the plant cell. These include, among others, diverse polyphenols, metal cations, and inorganic salts. Attention is also given to the biophysicochemical environment found in plant vacuoles that plays a fundamental role on the intermolecular and intramolecular associations displayed by anthocyanins. For example, anthocyanin Z-chalcones (retrochalcones) provide an unexpected open cavity for the ferric cation. Medicinal, nutritional, and industrial applications of anthocyanins are proposed.