1. a Université de Cergy-Pontoise , ENS, UMR CNRS 8029, SATIE, F-95000 , Cergy-Pontoise , France
2. b Department of Biotechnology , University of Chemical Technology and Metallurgy , BG-1756 , Sofia , Bulgaria
3. c Department of Organic Chemistry , University of Chemical Technology and Metallurgy , BG-1756 , Sofia , Bulgaria