Glycosidase inhibitors from the roots of Glyphaea brevis.

Ten phenylalkyl-substituted iminosugars (1-10) and a cinnamic acid derived glucoside (11) were isolated from the roots of Glyphaea brevis (Malvaceae). Their structures were elucidated by 1D and 2D NMR analysis, as well as by HR-ESIMS. Compounds 1-10 retain an unprecedented structure composed of an iminosugar-like core identified as 1-deoxyfuconojirimycin in glyphaeaside A1-A4 (1, 2, 5, 6), 1-deoxygalactonojirimycin in glyphaeaside B1-B5 (3, 4, 7-9) or 1-deoxynojirimycin in glyphaeaside C (10), substituted by a β-d-glucopyranose in compounds 2, 4, 6 and 9.