Sesquiterpenes and aliphatic diketones from cultures of the basidiomycete Conocybe siliginea.

Five new tremulane-type sesquiterpenes, 11,12-dihydroxy-1-tremulen-5-one (1), 11,12-epoxy-12beta-hydroxy-1-tremulen-5-one (2), 5alpha,12-dihydroxy-1-tremulen-11-yl 2(S)-pyroglutamate (3), 2alpha,11-dihydroxy-1(10)-tremulen-5,12-olide (4), and 10beta,11-dihydroxy-5,6- seco-1,6(13)-tremuladien-5,12-olide (5), as well as three new aliphatic diketones, 2,3-dihydroxydodecane-4,7-dione (9 and 10) and 1-hydroxydecane-2,5-dione (11), together with three known sesquiterpene analogues, tremulenediol A (6), conocenol B (7), and conocenolide A (8), were isolated from cultures of the basidiomycete Conocybe siliginea.