Two new sesquineolignans from the seeds of Crataegus pinnatifida and their β-amyloid aggregation inhibitory activitiy.

Two new sesquineolignans, hawthornsesquinins K and L (1 and 2), were isolated from the seeds of Crataegus pinnatifida. Their structures were determined by spectroscopic analyses, including 1D, 2D NMR and HRESIMS data. All isolated compounds were tested for their β-amyloid aggregation inhibitory activity and neuroprotective effects against H2 O2 -induced damage in SH-SY5Y cells. The results indicated that compound 1 showed prominent inhibition of Aβ1-42 aggregation and significant neuroprotective effect on H2 O2 -induced cellular damage in SH-SY5Y cells.