1. Department of Pharmaceutical Sciences, University of Florence, via Gino Capponi 9, 50121 Florence, Italy; Department of Bioorganic and Biopharmaceutic Chemistry, University of Pisa, via Bonanno 33, 56124 Pisa, Italy; and Officina Profumo Farmaceutica di Santa Maria Novella, via della Scala 16, 50100 Florence, Italy