title: Interaction of natural polyphenols with α-amylase in vitro: molecular property-affinity relationship aspect.
abstract: The relationship between the structural properties of natural polyphenols and their affinities for α-amylase were investigated by fluorescence titration analysis. The binding process with α-amylase was strongly influenced by the structural differences of the compounds under study. For instance, the methylation of the hydroxyl group in flavonoids increased their binding affinities for α-amylase by 2.14 to 7.76 times. The hydroxylation on rings A, B, and C of flavonoids also significantly affected their affinities for α-amylase. The glycosylation of isoflavones and flavanones reduced their affinities for α-amylase and the glycosylation of flavones and flavonols enhanced their affinities for α-amylase. Hydrogenation of the C2=C3 double bond of flavonoids decreased the binding affinities. The galloylated catechins had higher binding affinities with α-amylase than non-galloylated catechins and the pyrogallol-type catechins had higher affinities than the catechol-type catechins. The presence of the galloyl moiety is the most decisive factor. The glycosylation of resveratrol decreased its affinity for α-amylase. The esterification of gallic acid significantly reduced the affinity for α-amylase. The binding interaction between polyphenols and α-amylase was mainly caused by hydrophobic forces.
authors: Department of Biology, College of Life & Environment Science, Shanghai Normal University, 100 Guilin Rd, Shanghai 200234, PR China. jianboxiao@yahoo.com
authors: Jianbo
authors: J
authors: Xiao
authors: Guoyin
authors: G
authors: Kai
authors: Xiaoling
authors: X
authors: Ni
authors: Fan
authors: F
authors: Yang
authors: Xiaoqing
authors: X
authors: Chen
mesh_terms: D001665:Binding Sites; D005419:Flavonoids / Q000737:chemistry*; D005453:Fluorescence; D006031:Glycosylation; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D006900:Hydroxylation; D008745:Methylation; D008968:Molecular Conformation; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry*; D059808:Polyphenols; D011485:Protein Binding; D013329:Structure-Activity Relationship; D000516:alpha-Amylases / Q000737:chemistry*
chemical_list: D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D000516:alpha-Amylases