The antioxidant function induced by Nrf2 protects the liver from damage. We found a novel Nrf2 activator named compound 25 via structural modification of compound 1 we previously reported. In vitro, compound 25 induced Nrf2 transport into the nucleus and protected hepatocyte L02 cells from APAP-induced cytotoxicity via activating the Nrf2-ARE signaling pathway. In vivo, 25 exhibited therapeutic effects in a mouse model of acute liver injury induced by acetaminophen (APAP) by up-regulating Nrf2-dependent antioxidases and down-regulating liver injury markers in serum. Together, these results indicated that 25 is a potent Nrf2/ARE activator both in vitro and in vivo. The drug-like properties of compound 25 further revealed its potential for development as a therapeutic drug against acute liver injury.