1. Department of Pharmaceutical Sciences, University of Padova, Via Marzolo 5, 35131 Padova, Italy, Department of Chemical Sciences, University of Padova, Via Marzolo 1, 35131 Padova, Italy, Department of Organic Chemistry, University of Santiago de Compostela, Santiago de Compostela, Spain, and Department of Biochemistry and Molecular Biology, University of Ferrara, Via Fossato di Mortara 74, 44100 Ferrara, Italy