β-Cembrenediol (β-CBT) is a natural product from tobacco plants that is found in cigarette smoke condensate. β-CBT inhibits induction of the early antigen of Epstein-Barr virus (EA-EBV) by 12-O-tetradecanoylphorbol-13-acetate (TPA) in vitro (IC50 = 21.9 μM). It inhibits tumor promoting effects of TPA on 7,12-demethylbenz[a]anthracene-induced papilloma formation in vivo. β-CBT is also released into soil by flue-cured tobacco plants and exerts autotoxicity as well as phytotoxic activity against L. sativa seedlings.