Structure and neurotrophic activity of novel sesqui-neolignans from the pericarps of Illicium fargesii

The structures of three new sesqui-neolignans, fargenin (1) and fargenones A and B (2 and 3), together with two previously known sesqui-neolignans, macranthol (4) and isodunnianol (5), isolated from the methanol extract of the pericarps of Illicium fargesii were elucidated on the basis of spectroscopic data. Compounds 1-3 are the second three examples of the sesqui-neolignans that contain a variety of non-aromatic rings, and their plausible biosynthetic routes from chavicol are proposed. Among the isolated sesqui-neolignans, isodunnianol has been found to exhibit neurite outgrowth-promoting activity at the concentration ranging from 0.1 to 10 μM in the primary cultured rat cortical neurons.