1. Department of Chemistry, Faculty of Science, Ataturk University, Erzurum, Turkey,
2. Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Ataturk University, Erzurum, Turkey,
3. Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia, and
4. Neurofarba Department and Laboratorio di Chimica Bioinorganica, Polo Scientifico, Universita' degli Studi di Firenze, Sesto Fiorentino (Firenze), Italy