1. Viikki Drug Discovery Technology Center, Department of Pharmacy, FIN-00014 University of Helsinki, P.O. Box 56, FIN-00014, Helsinki, Finland, Institute of Chemistry, State University of Campinas, UNICAMP, CP 6154 13083-970, Campinas, SP Brazil, and Department of Pharmacy, Division of Pharmaceutical Chemistry, University of Helsinki, P.O. Box 56, FIN-00014, Helsinki, Finland