1. Novosibirsk Institute of Bioorganic Chemistry, Siberian Division of Russian Academy of Sciences, 8 Lavrentieva Avenue, Novosibirsk 630090, Russia, UMR 5097 CNRS-Université Victor Segalen Bordeaux 2, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France and IFR 66 Bordeaux, France, and University of Genoa, Department of Pharmaceutical Sciences, Viale Benedetto XV, 3, Genoa-3, Italy