1. Department of Chemistry, University of Ferrara, Via Luigi Borsari 46, I-44100 Ferrara, Italy; Department of Pharmaceutical Sciences, University of Ferrara, Via Fossato di Mortara 17-19, I-44100 Ferrara, Italy; Department of Evolutionary and Experimental Biology, University of Bologna, Via Irnerio 42, I-40126 Bologna, Italy; and Department of Biology, Section of Botany, Pharmaceutical Biology Laboratory, University of Ferrara, C.so Porta Mare 2, I-44100 Ferrara, Italy