1. Institute of Protein Biochemistry, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
2. Telethon Institute of Genetics and Medicine, Via Pietro Castellino 111, 80131 Naples, Italy
3. Department of Medicinal Chemistry and Pharmacognosy, The University of Illinois at Chicago, 833 S. Wood St., Chicago, IL 60612, U.S.A.