LKY-047, a derivative of Decursin, is a highly effective and specific reversible competitive inhibitor of cytochromeP45022J2 (CYP2J2), with an IC 50 value of 1.7 μM. LKY-047 does not display inhibitory activity against other human P450 enzymes including CYPs 1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, and 3A.