A new dilignan from the twigs and leaves of Archidendron clypearia.

Previous work has shown that the lignans from the twigs and leaves of Archidendron clypearia (Jack) I.C.N. possess anti-β-amyloid aggregation activity. Here we report a new dilignan, archidendronin A (1), along with one known sesquilignan (2). Their structures were determined by extensive spectroscopic methods, including UV, HRESIMS, 1 D and 2 D NMR data. The inhibitory activity on Aβ1-42 aggregation was screened by ThT assay with curcumin as the positive control, and compounds 1 and 2 showed inhibition rate of 60.0% and 64.4% at 20 μM, respectively.[Formula: see text].