Terpenoids from Russula lepida and R. amarissima (Basidiomycota, Russulaceae)

Four aristolane sesquiterpenes were isolated from the fruiting bodies of Russula lepida and R. amarissima, namely (1R,2S)-1,2-dihydroxyaristolone (6), (2S,11S)-2,12-dihydroxy-aristolone (7), (1R,2S,11S)-1,2,12- trihydroxyaristolone (8), (1S,2S,11S)-1,2,12-trihydroxy-aristolone (9). In addition, a seco-cucurbitane tri- terpene, i.e. 3,4-secocucurbita-4,24E-diene-3-hydroxy-26-carboxylic acid (14) was isolated from both species. The configuration at C-2 of the already known rulepidol (2-hydroxyaristolone, 5) was corrected as S instead of R. Several more aristolane and nardosinane sesquiterpenes, as well as cucurbitane triter- penes, already reported both from European and Chinese samples of R. lepida, were also isolated. Com- pound 14 showed moderate cell growth inhibitory activity.