Six New Lanostane Triterpenoids from the Fruiting Body of Tyromyces Sambuceus and Antiproliferative Activity

During the search for secondary metabolites with antiproliferative activity, six new lanostane triterpenoids, tyrosamic acids A-F (1–6) together with ten known compounds (7–16), were isolated from the fruiting body of Tyromyces sambuceus. Their structures were elucidated using MS analyses, extensive 2D-heteronuclear NMR data interpretation and the structure of 3 was further confirmed by single-crystal X-ray data analyses. All lanostane triterpenoids (1–16) possesses a carboxy group at C-20 position and their strength of antiproliferative activity was affected by the presence or absence of a hydroxy group at C-15 position and at the side chain. Four of the compounds (1, 6, 10, 14) showed antiproliferative activities against human cancer cell lines with IC50 values of 16.8–48.3 μM (HL-60).