1. Department of Toxicology, University of Cagliari, I-09124 Cagliari, Italy, Department of Pharmaceutical Sciences and Biotechnology Center, University of Ferrara, I-44100 Ferrara, Italy, Department of Pharmacology, Tohoku Pharmaceutical University, 4-1 Komatsushima 4-chome, Aoba-Ku, Sendai 981-8558, Japan, Medicinal Chemistry Group, Laboratory of Pharmacology, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA