Cochlearols A and B, polycyclic meroterpenoids from the fungus Ganoderma cochlear that have renoprotective activities.

(+)- and (-)-cochlearols A (1) and B (2), two meroterpenoids with novel polycyclic skeletons, were isolated from the fruiting bodies of the fungus Ganoderma cochlear. Their structures and stereochemistry were determined by using spectroscopic, computational and single-crystal X-ray diffraction methods. Cochlearol A is a new normeroterpenoid containing a naturally unusual dioxaspiro[4.5]decane motif. Biological studies showed that (-)-2 is a strong inhibitor of p-Smads, exhibiting renoprotective activities in TGF-β1 induced rat renal proximal tubular cells.