New lanostane-type triterpenoids from the fruiting body of Ganoderma hainanense

Five new lanostane-type triterpenoids, ganoderenses A-E (1-5), two new lanostane nor-triterpenoids, ganoderenses F and G (6 and 7), along with 13 known analogues (8-20) were isolated from the fruiting body of Ganoderma hainanense. Their structures were determined by combined chemical and spectral methods, and the absolute configurations of compounds 1 and 13 were confirmed by single crystal X-ray diffraction. All compounds were evaluated for inhibitory activity against thioredoxin reductase (TrxR), a potential target for cancer chemotherapy with redox balance and antioxidant functions, but were inactive.