Four novel seconeodolastane diterpenoids, named tricholomalides D-G, were isolated, together with the known tricholomalide C, from the fruiting bodies of Tricholoma ustaloides Romagn., a species belonging to the large Tricholoma genus of higher mushrooms (Basidiomycota, family Tricholomataceae). They were isolated through multiple chromatographic separations, and the structures, including the absolute configuration, were established through a detailed analysis of MS, NMR, and CD spectral data and comparison with related compounds reported in the literature, which has been thoroughly revised.
Keywords: CD spectra; Tricholoma ustaloides; Tricholomataceae (Basidiomycota); absolute configuration; seconeodolastane diterpenoids; tricholomalides.