Two new sesquiterpenoids, tremulenolide D (1) and muurolane-10β,15-diol (2), together with four known sesquiterpenoids, tremulenediol A (3), 2β-hydroxy-α-candinol (4), epicubenol (5), and 3β-hydroxy-δ-candinol (6), were isolated from cultures of the fungus Ceriporia alachuana. The structures of new compounds were determined by extensive spectroscopic analyses. Structurally, compounds 1 and 3 are tremulane-type sesquiterpenoids with an unusual perhydroazulene carbon skeleton. [ABSTRACT FROM AUTHOR]