Three bisabolane sesquiterpenoids and a phenolic derivative from the fungus Stereum hirsutum

To explore the secondary metabolites of the higher fungus Stereum hirsutum. The structures of these compounds were elucidated by extensive spectroscopic analyses and NMR calculations. Three new bisabolane sesquiterpenoids, sterene acids A–C (1–3), and one new phenolic derivative, sterephenol A (4), were isolated from the higher fungus S. hirsutum. Compound 1 is the first example of bisabolane sesquiterpenoid bearing an allene group. It is also the first time to discover bisabolane sesquiterpenoids from the fungus S. hirsutum.