1. Department of Pharmacy, Division of Pharmaceutical Chemistry, University of Helsinki, P.O. Box 56, FIN-00014, Helsinki, Finland, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-0033, Japan, Department of Pharmacy, Division of Pharmacognosy, University of Helsinki, P.O. Box 56, FIN-00014, Helsinki, Finland, and Department of Pharmacy, Viikki Drug Discovery Technology Center, P.O. Box 56, FIN-00014 University of Helsinki, Finland