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.