[1] Paisij Hilendarski Univ Plovdiv, Dept Biochem & Microbiol, BG-4000 Plovdiv, Bulgaria
[2] Paisij Hilendarski Univ Plovdiv, Dept Analyt Chem, BG-4000 Plovdiv, Bulgaria
[3] CSIC, Inst Quim Avancada Catalunya, Dept Biol Chem & Mol Modeling, ES-08034 Barcelona, Spain