1. Institute of Pharmacy, Division of Pharmaceutical and Medicinal Chemistry, Paracelsus Medical Private University Salzburg, Salzburg, Austria;
2. Planta Naturstoffe, Vienna, Austria;
3. Department of Pharmaceutical Chemistry, Division of Drug Design and Medicinal Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria;
4. Department of Chemistry, Division of Biochemistry, University of Natural Resources and Life Sciences, Vienna, Austria