Highly oxygenated lanostane triterpenoids from Ganoderma applanatum as a class of agents for inhibiting lipid accumulation in adipocytes

Ganoderma triterpenoids (GTs), a class of major active constituents in Ganoderma species, play an important role in the anti-obesity effect of Ganoderma fungi. In the study, seventeen new highly oxygenated lanostane tri-terpenoids, ganoapplanoids A-Q (1-17), together with five previously reported compounds (18-22), were isolated from the fruiting bodies of Ganoderma applanatum. Their structures were confirmed by comprehensive spectroscopic analyses, single-crystal X-ray diffraction and Mo-2(OAc)(4) induced CD cotton effect. Structurally, compound 6 represents the first example of 2-norlanostane triterpenoid possessing an unusual semiacetal moiety. Furthermore, isolates (1-5, 7-11, 13-22, 3a) were evaluated for regulatory effects on lipid accumulation by 3T3-L1 adipocytes model. Among them, compounds 11 and 17 exhibited significant potency in blunted adipogenesis activities dose-dependently. Meanwhile, compounds 11 and 17 reduced triglyceride (TG) and total cholesterol (TC) levels in the adipocytes. These results supported that the highly oxygenated lanostane tri-terpenoids from G. applanatum may serve as agents for inhibiting the lipid accumulation in adipocytes and the G. applanatum provided an important source for searching new drugs to treat obesity.