1 Laboratory of Biologically Active Substances, Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, 139 Ruski Blvd., BG-4000 Plovdiv, Bulgaria; Innovative-Technological Center Ltd., 20 Dr. G. M. Dimitrov Str., BG-4000 Plovdiv, Bulgaria.
2 Department of Pharmaceutical Chemistry, School of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, NO-0316 Oslo, Norway.
3 Department of Drug Discovery Science, Kitasato Institute for Life Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, JP-108-8641 Tokyo, Japan.
4 Department of Free Radical Pathophysiology, Institute of Biophysics, Czech Academy of Sciences, 135 Kralovopolska, CZ-612 65 Brno, Czech Republic.
5 Department of Free Radical Pathophysiology, Institute of Biophysics, Czech Academy of Sciences, 135 Kralovopolska, CZ-612 65 Brno, Czech Republic; International Clinical Research Center - Center of Biomolecular and Cellular Engineering, St. Anne's University Hospital Brno, 53 Pekarska, CZ-656 91 Brno, Czech Republic.
6 Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, NO-0315 Oslo, Norway.
7 The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 26, BG-1113 Sofia, Bulgaria.
8 Department of Biotechnology, University of Food Technologies, 26 Maritza Blvd., BG-4002 Plovdiv, Bulgaria.
9 Laboratory of Biologically Active Substances, Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, 139 Ruski Blvd., BG-4000 Plovdiv, Bulgaria; Innovative-Technological Center Ltd., 20 Dr. G. M. Dimitrov Str., BG-4000 Plovdiv, Bulgaria. Electronic address: lbas@plov.omega.bg.