Polyphenol interactions. Part 1. Introduction; some observations on the reversible complexation of polyphenols with proteins and polysaccharides

Early studies of the interactions between polyphenols and proteins are reviewed. The complexation of some simple phenols and a group of biosynthetically inter-related esters of gallic acid with bovine serum albumin (BSA) is examined by equilibrium dialysis and microcalorimetry. The phenomenon is pH dependent. The results indicate that molecular size and conformational flexibility of the polyphenol substrate lead to enhanced interactions with the protein. Preliminary studies with polysaccharides indicate that the binding here is pH independent. These studies suggest that whilst the binding of polyphenols to these macromolecules is influenced by similar structural features the ability of the polysaccharide to form structures which encapsulate the polyphenol is, in this instance, a further critical feature of the complexation.