1. Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 20, P.O. Box 177, HR-10000 Zagreb, Croatia, Division of Organic Chemistry and Biochemistry, “Rudjer Bošković” Institute, P.O. Box 180, HR-10002 Zagreb, Croatia, and Division of Molecular Medicine, “Rudjer Bošković” Institute, Bijenička cesta 54, P.O. Box 180, HR-10000 Zagreb, Croatia