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

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