1. Department of Pharmaceutical and Pharmacological Sciences, University of Padova, via Marzolo 5, Padova 35131, Italy
2. Department of Chemistry, University of Jyvaskyla, P.O. Box 35, Jyväskylä 40014, Finland
3. Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, United States