1. Department of Chemistry, University of Florence, Via della Lastruccia 3, Sesto Fiorentino, Florence, Italy, Department of Anatomy, Histology and Forensic Medicine, Section of Histology, University of Florence, V. le G. Pieraccini, 6, Florence, Italy, Department of Chemistry and Industrial Chemistry, University of Pisa, Via Risorgimento 35, Pisa, Italy, and Department of Preclinical and Clinical Pharmacology, University of Florence, V. le G. Pieraccini, 6, Florence, Italy