Dimeric and Monomeric Dihydrostilbenes from the Roots of Stemona mairei together with Their Hypoglycemic Activities

A bstract A carefully performed phytochemical investigation of the roots of Stemona mairei (Stemonaceae) led to the discovery of six so far undescribed dihydrostilbene dimers maistilbene A–F and four monomers maistilbene G–J. This is the first report of stilbenoids of this plant species and the first report of dimeric dihydrostilbenes from this plant family. The absolute configuration of these compounds was determined by a combination of Mo2(AcO)4-induced ECD spectra and quantum chemical calculation of NMR chemical shift, ECD and spin-spin coupling constants. Maistilbene G could increase the glucose consumption in L6 myotubes, disclosing a new hypoglycemic candidate.