β-Resorcylic acid derivatives with α-glucosidase inhibitory activity from Lasiodiplodia sp ZJ-HQ1, an endophytic fungus in the medicinal plant Acanthus ilicifolius

Three new beta-resorcylic acid derivatives, compounds 1-3, along with six known analogues (4-9) were isolated from an endophytic fungus Lasiodiplodia sp. ZJ-HQ(1) derived from medicinal plant Acanthus ilicifolius. Their structures were elucidated by 1D and 2D NMR spectroscopic analysis, high resolution mass spectrometric (HREIMS) data, and X-ray crystallography. The absolute configurations of compounds 1 and 2 were determined by the modified Mosher's method. Compounds 1-7 showed more potent inhibitory effects against a-glucosidase activity than the clinical alpha-glucosidase inhibitor acarbose. (C) 2015 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.