Inhibitors of α-amylase and α-glucosidase from Andromachia igniaria Humb. & Bonpl.

Two new flavonoids, (2S)-3',4',7,8-tetrahydroxyflavanone 7-O-(6 ''-O-acetyl)-beta-D-glucopyranoside (1) and 3',4',7,8-tetrahydroxyflavone 7-O-(6 ''-O-acetyl)-beta-D-glucopyranoside (2) along with fourteen known compounds were isolated from Andromachia igniaria aerial part extracts. Their structures were determined via spectroscopic analyses including 2D NMR. The hypoglycemic properties of all extracts and pure compounds were evaluated measuring alpha-amylase and alpha-glucosidase inhibitory effects. The n-butanol among the extracts was found to be the best inhibitor of both alpha-amylase and alpha-glucosidase enzymes, while among compounds the most active were: bidenoside F and luteolin 4'-O-beta-D-glucopyranoside as alpha-amylase inhibitors; eriodictyol, butein and okanin as alpha-glucosidase inhibitors. Results demonstrated that A. igniaria can represent an important natural source with high biological values, helpful to control postprandial hypoglycemia. (C) 2015 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.