Acetylenic sesquiterpenoids from cultures of the basidiomycete Stereum cf. hirsutum BCC 26597.

A new acetylenic sesquiterpenoid, stereyne A (1), and its acetonide derivative, stereyne B (2), were isolated from cultures of the basidiomycete Stereum cf. hirsutum BCC 26597. The structures were elucidated by spectroscopic analysis and a chemical correlation. Their absolute configurations were determined by application of the modified Mosher's method. They represent new structural type of sesquiterpenoids from Stereum.