title: A review on structure-activity relationship of dietary polyphenols inhibiting α-amylase.
abstract: The inhibitory effects of dietary polyphenols against α-amylase have attracted great interest among researchers. The aim of this review is to give an overview of the research reports on the structure-activity relationship of polyphenols inhibiting α-amylase. The molecular structures that influence the inhibition are the following: (1) The hydroxylation of flavonoids improved the inhibitory effect on α-amylase; (2) Presence of an unsaturated 2,3-bond in conjugation with a 4-carbonyl group has been associated with stronger inhibition; (3) The glycosylation of flavonoids decreased the inhibitory effect on α-amylase depending on the conjugation site and the class of sugar moiety; (4) The methylation and methoxylation of flavonoids obviously weakened the inhibitory effect; (5) The galloylated catechins have higher inhibition than nongalloylated catechins; the catechol-type catechins were stronger than the pyrogallol-type catechins; the inhibition activities of the catechins with 2,3-trans structure were higher than those of the catechins with 2,3-cis structure; (6) Cyanidin-3-glucoside showed higher inhibition against than cyanidin and cyanidin-3-galactoside and cyanidin-3,5-diglucoside had no inhibitory activity; (7) Ellagitannins with β-galloyl groups at glucose C-1 positions have higher inhibitory effect than the α-galloyl and nongalloyl compounds and the molecular weight of ellagitannins is not an important element.
authors: Department of Biology, College of Life & Environment Science, Shanghai Normal University, 100 Guilin Road, Shanghai 200234, P. R. China. jianboxiao@yahoo.com
authors: Jianbo
authors: J
authors: Xiao
authors: Xiaoling
authors: X
authors: Ni
authors: Guoyin
authors: G
authors: Kai
authors: Xiaoqing
authors: X
authors: Chen
mesh_terms: D000872:Anthocyanins / Q000737:chemistry; D002392:Catechin / Q000737:chemistry; D003373:Coumaric Acids / Q000737:chemistry; D005697:Galactosides / Q000737:chemistry; D005960:Glucosides / Q000737:chemistry; D006031:Glycosylation; D006801:Humans; D047348:Hydrolyzable Tannins / Q000737:chemistry; D006900:Hydroxylation; D008745:Methylation; D015394:Molecular Structure; D059808:Polyphenols / Q000737:chemistry*; D044945:Proanthocyanidins / Q000737:chemistry; D013329:Structure-Activity Relationship; D000516:alpha-Amylases / Q000037:antagonists & inhibitors / Q000737:chemistry*
chemical_list: D000872:Anthocyanins; D003373:Coumaric Acids; D005697:Galactosides; D005960:Glucosides; D047348:Hydrolyzable Tannins; D059808:Polyphenols; D044945:Proanthocyanidins; C462279:cyanidin-3-O-beta-glucopyranoside; C017154:cyanidin; D002392:Catechin; D000516:alpha-Amylases; C546035:cyanidin 3-galactoside