1. Institute of Pharmacy, Computer Aided Molecular Design Group, University of Innsbruck, Innrain 52c, Austria, Center for Molecular Biosciences Innsbruck (CMBI), Peter-Mair-Str.1, A-6020 Innsbruck, Austria, and Inte:Ligand GmbH, Clemens Maria Hofbauer-Gasse 6, A-2344 Maria Enzersdorf, Austria