Lanostane-type triterpenoids from the mycelial mat of Ganoderma lucidum and their hepatoprotective activities

Ganoderma lucidum (G. lucidum), a well-known Polyporaceae family fungus, is valued for its edibility and medicinal properties. It is a rich source of active polysaccharides and triterpenoids. However, obtaining material for medicinal purposes relies on artificial cultivation in a greenhouse, which requires large amounts of tree trunk due to the low biomass transformation rate. Therefore, an effective and environment-friendly culture method should be developed and the chemical compounds in the cultured material should be studied. Here we report the isolation and structural elucidation of 10 undescribed lanostane triterpenoids and 21 known compounds from statically cultured mycelial mat of G. lucidum. The hepatoprotective activity of these compounds in H₂O₂-induced HepG2 cells was evaluated. The structure-activity relationship is discussed. Our results demonstrated that twelve ganoderic acid derivatives possess significant hepatoprotective activities, as judged by suppressed activities of ALT, AST and LDH and increased GSH levels in H₂O₂-injured HepG2 cells.