Polysaccharide gels hydrophobic association

Polyethylene oxides and amyloses (Mr > 4000) readily complex with polyphenols but quantitative studies have been severely limited by the availability of water-soluble polysaccharides with clearly defined molecular characteristics. Semi-quantitative studies show that the association of polyphenols with polysaccharides is - in contrast to that with proteins - broadly independent of pH. Molecular size and flexibility are likewise critical factors but, significantly, where the polysaccharide can sequester the hydrophobic aryl residues of the polyphenol - holes in a crystal lattice (cellulose) or hydrophobic cavities (amylose and polysaccharide gels) - then complexation is substantially enhanced. Open, flexible, filamentous polysaccharides, such as the l-a-6-dextrans conversely bind phenolic substrates very poorly. It is interesting to note that model polysaccharide holes - in the form of the a- and 3- cyclodextrins - can sequester the aryl residues of certain polyphenols in the core of the molecule. In doing... 

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