Derivatives of Vibralactone from Cultures of the Basidiomycete Boreostereum vibrans

Four new natural products possessing vibralactone skeleton, 1,5-secovibralactone (1), vibralactone B (2), vibralactone C (3) and acetylated vibralactone (4), together with known compound vibralactone (5), had been isolated from cultures of the basidiomycete Boreostereum vibrans. The structures of 1-4 were elucidated on the basis of spectroscopic methods. The absolute configuration of 1 was suggested to be S by computational methods.