1. a Department of Chemistry and Pharmacy , University of Erlangen-Nürnberg – Egerlandstraße 1 – 91058 Erlangen , Germany
2. b Department of Chemistry and Pharmacy, Computer Chemistry Center , University of Erlangen-Nürnberg , Nägelsbachstr. 25, 91052 Erlangen , Germany
3. c Faculty of Pharmacy and Biochemistry , University of Zagreb , A. Kovačića 1 – 10000 Zagreb , Croatia