1. Department of Chemistry, College of Science, Sultan Qaboos University, Al Khod, P.O. Box 36, Muscat 123, Oman
2. Department of Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Eberhard Karls Universität Tübingen, D-72076 Tübingen, Germany
3. Tübingen Center for Academic Drug Discovery (TüCAD2), D-72076 Tübingen, Germany