Our previous research has shown that lanostane triterpenoids from Ganoderma applanatum exhibit significant anti-adipogenesis effects. In order to obtain more structurally diverse lanostane triterpenoids to establish a structure-activity relationship, we continued the study of lanostane triterpenoids from the fruiting bodies of G. applanatum, and forty highly oxygenated lanostane-type triterpenoinds (1-40), including sixteen new compounds (1-16), were isolated. Their structures were elucidated using NMR spectra, X-ray crystallographic analysis, and Mosher's method. In addition, some of their parts were evaluated to determine their anti-adipogenesis activities in the 3T3-L1 cell model. The results showed that compounds 16, 22, 28, and 32 exhibited stronger anti-adipogenesis effects than the positive control (LiCl, 20 mM) at the concentration of 20 μM. Compounds 15 and 20 could significantly reduce the lipid accumulation during the differentiation process of 3T3-L1 cells, comparable to the untreated group. Their IC50 values were 6.42 and 5.39 μM, respectively. The combined results of our previous and present studies allow us to establish a structure-activity relationship of lanostane triterpenoids, indicating that the A-seco-23→26 lactone skeleton could play a key role in anti-adipogenesis activity.
Keywords: Ganoderma applanatum; Mosher’s method; anti-adipogenesis activity; lanostane triterpenoid; structure–activity relationship.