1. Theoretical Chemistry, Center of Molecular Biosciences, Faculty of Chemistry and Pharmacy, University of Innsbruck, Innrain52a, A-6020 Innsbruck, Austria, and Department of Lead Discovery, Boehringer Ingelheim Pharma GmbH & Co. KG, Birkendorfer Strasse 65, D-88397 Biberach/Riss, Germany