Scabronine M, a novel inhibitor of NGF-induced neurite outgrowth from PC12 cells from the fungus Sarcodon scabrosus.

A novel cyathane diterpenoid, designated scabronine M (1), was isolated from the fruiting bodies of the mushroom Sarcodon scabrosus together with 10 known compounds. The structure of the new compound was elucidated on the basis of extensive spectroscopic analysis including 2D-NMR. Among these compounds, only scabronine M (1) significantly inhibited dose-dependently NGF-induced neurite outgrowth in PC12 cells without cytotoxicity, possibly through suppressing the phosphorylation of the receptor Trk A and the extracellular signal regulated kinases (ERK). This is the first report of novel neurite outgrowth-inhibiting activity in PC12 cells of this group of diterpenoids.