The Chemical Constituents of Diaphragma Juglandis Fructus and Their Inhibitory Effect on α-Glucosidase Activity

Abstract

In our current investigation, 37 constituents (1–37), including 11 megastigmanes (1–11), 17 flavonoids (12–28) and 9 phenylpropanoids (29–37), were isolated from a 70%-EtOH extract of Diaphragma juglandis Fructus. Among them, compounds 1–3, 12 and 29 were new compounds and their structures were elucidated on the basis of physicochemical evidence and meticulous spectro-scopic analysis (NMR, HRESIMS and CD). Compounds 13, 16, 21 and 28 showed moderate inhibitory effect on α-glycosidase inhibitory activities, with IC50 values being in the range of 29.47–54.82 µM and stronger than the positive control (acarbose, 60.01 ± 4.82 µM).