1. Helmholtz Institute for Pharmaceutical Research Saarland; Department of Drug Design and Optimization; Campus E8.1 66123 Saarbrücken Germany
2. Department of Biochemistry; Saarland University; Campus B2.2 66123 Saarbrücken Germany
3. Department of Pharmacy, Pharmaceutical and Medicinal Chemistry; Saarland University; Campus C2.3 66123 Saarbrücken Germany