1. Department of Chemistry, University of Kaiserslautern, Division of Food Chemistry and Environmental Toxicology, Erwin Schrödinger Strasse, D-67663 Kaiserslautern, Germany, Division of Chemical Carcinogenesis, American Health Foundation, Valhalla, New York 10595, Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, and University of Minnesota Cancer Center, Minneapolis Minnesota 55455