1. Organic Chemistry Department Peoples' Friendship University of Russia 6 Miklukho-Maklaya St. Moscow 117198 Russia
2. Department of Pharmacy-Drug Sciences University of Bari Aldo Moro Via E. Orabona 4 70125 Bari Italy
3. Department of Biomedical Sciences and Human Oncology University of Bari Aldo Moro Piazza Giulio Cesare 11 70124 Bari Italy