Neuroprotective compounds from the bulbs of Lycoris radiata

Three new alkaloids (1-3) and one new phenolic glycoside (4), together with twenty five known alkaloids (5-29), were isolated from the bulbs of Lycoris radiata collected from Huaihua county of Hunan province, China. Their structures were elucidated on the basis of comprehensive NMR and MS spectroscopic analysis. The isolated alkaloids were evaluated for their neuroprotective activities against CoCl2, H2O2 and A beta(25-35)-induced SH-SY5Y cell injuries. Compounds 1-3 showed significant neuroprotective effects against H2O2 or CoCl2-induced SH-SY5Y cell death, while compound 3 exhibited significant neuroprotective effects against A beta(25-35)-induced SH-SY5Y cell injury. The known alkaloids 5-29 also exhibited similar bioactivities of different degrees. These findings highlight the fact that the over 100 Amaryllidaceae alkaloids may have a big potential to neuroprotective activity. (C) 2013 Elsevier B.V. All rights reserved.