PDM 2 is an analog of resveratrol acting as a potent and selective Aryl Hydrocarbon Receptor (Ah Receptor, AhR) antagonist. The Ah Receptor is a ligand-dependent intracellular transcription factor whose ligands include some of the most infamous xenobiotics, including dioxin, benzo[a]pyrene, and numerous polyaromatics from soot and coal tar.