1. Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, 825, NE 13th Street, Oklahoma City, OK 73104, USA
2. Department of Pharmaceutical Biochemistry, Poznan University of Medical Sciences, 4, Święcicki Street, 60-781 Poznań, Poland
3. Department of Organic Chemistry, Poznan University of Medical Sciences, 6, Grunwaldzka Street, 60-780 Poznań, Poland