New pentacyclic triterpenoids isolated from Leptopus chinensis and their hepatoprotective activities on tert-butyl hydroperoxide-induced oxidative injury

Eight unknown pentacyclic triterpenoids (1–4 and 8–11), along with eight known analogues (5–7 and 12–16) have been first isolated from the dried whole plant of Leptopus chinensis. The structures of the new compounds were determined by comprehensive spectroscopic methods, including 1D and 2D NMR, as well as HRESIMS measurements. Meanwhile, the hepatoprotective activities of the isolated compounds were preliminarily evaluated, and the results indicated that compounds 2, 5 and 16 possess potent protective effects on tert-butyl hydroperoxide (t-BHP)-induced oxidative injury in vitro, and further study revealed that 16 significantly alleviates t-BHP-induced hepatotoxicity by effectively improving cell viability and decreasing reactive oxygen species (ROS) generation and the cell apoptosis rate in HepG2 cells.