[Au(L4)(CyJohnPhos)]SbF6 is a gold containing complex. [Au(L4)(CyJohnPhos)]SbF6 inhibits cyclooxygenase-1/2 ( COX-1/2 ), inhibits the proliferation ( IC 50 is 0.98 μM) and induces apoptosis in colon cancer cell Caco2-/TC7. [Au(L4)(CyJohnPhos)]SbF6 is also an inhibitor for thioredoxin reductase ( TrxR ), thereby exhibits antioxidant activity by modulating ROS levels.