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

Abstract

Three new β-resorcylic acid derivatives, compounds 1–3, along with six known analogues (4–9) were isolated from an endophytic fungus Lasiodiplodia sp. ZJ-HQ1 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 α-glucosidase activity than the clinical α-glucosidase inhibitor acarbose.