1. Department of Therapeutic and Pharmaceutical Chemistry University of Lisbon Av. Prof. Gama Pinto 1649-003 Lisboa Portugal
2. Department of Biological Sciences University of Porto Rua de Jorge Viterbo Ferreira 228 4050-313 Porto Portugal
3. Rogel Cancer Center, Medical School University of Michigan Ann Arbor MI 48109 USA
4. Department of Biotechnology, Chemistry and Pharmacy University of Siena via Aldo Moro 2 53100 Siena Italy
5. Rogel Cancer Center, College of Pharmacy University of Michigan Ann Arbor MI 48109 USA