Number of galloyl moieties and molecular flexibility are both important in alpha-amylase inhibition by galloyl-based polyphenols

, indicating that the polyphenol-PPA binding interactions resulted in enzyme inhibition. In addition, the binding interactions were suggested to result from the hydrogen bonding and π-π conjugation forces between the free GMs and amino acid residues at the active sites of PPA, whereas the chemical linkage of the GMs with additional polyphenol groups limited these interactions. Furthermore, the hypoglycemic effects of two polyphenols with 5 free GMs indicate that GMs may be considered a functional fragment involved in the alleviation of the symptoms of type II diabetes through α-amylase inhibition.