Neuroprotective constituents from the fruits of Maclura tricuspidata

Cudraisoflavone L − T (1–11), cudradihydrochalcone A (12), and cudrabibenzyl A (13), together with 41 known constituents, were isolated from the fruits of Maclura tricuspidata (formerly known as Cudrania tricuspidata). Their structures were determined by spectroscopic and chemical methods including electronic circular dichroism. All isolated compounds were evaluated for their neuroprotective effects against 6-hydroxydopamine (6-OHDA)-induced cell death in human neuroblastoma SH-SY5Y cells, of these six compounds exhibited activities with EC₅₀ values of 4.5–18.6 μM. Furthermore, the neuroprotective effects against oxygen glucose deprivation (OGD)-induced cell death of all isolated constituents, together with 37 previously reported isoflavones were evaluated. Four compounds showed neuroprotective activities with EC₅₀ values of 3.5–11.9 μM.