Davallialactone (1) and inoscavin A (2) isolated from Phellinus linteus showed significant prolyl endopeptidase competitive inhibition with $IC_{50}$ values of 20.0${pm}$0.1 and 12.2${pm}$0.1 ${mu}M$ and $K_i$ values of 15.6${pm}$0.3 and 8.3${pm}$0.1 ${mu}M$, respectively. They also exhibited strong antioxidant capacities against the ABTS radical system with $EC_{50}$ values of 2.61${pm}$0.01, 13.3${pm}$0.05 ${mu}M$, respectively.