Seven new sesquineolignans isolated from the seeds of hawthorn and their neuroprotective activities

Seven new sesquineolignans (1–7) were isolated from the 70% ethanolic extract of the hawthorn seeds. Their structures were established by comprehensive spectroscopic analyses including 1D, 2D NMR, CD and HRESIMS data. The neuroprotective activity of the isolated sesquilignans towards H2O2-induced damage in human neuroblastoma SH-SY5Y cells was investigated. All of these sesquineolignans exhibited significant neuroprotective activity towards damaged SH-SY5Y cells, compared with the positive control (Trolox). Among them, 6 displayed the most potent neuroprotective ability with the survival rate of 90.74% at the concentration of 50 μM. Moreover, Hoechst 33258 staining and Annexin V/PI analysis proved that 6 could protect damaged SH-SY5Y cells through inhibiting cellular apoptosis.