1. Department of Chemistry, York Structural Biology Laboratory (YSBL) University of York Heslington York YO10 5DD UK
2. Department of Bio-organic Synthesis, Leiden Institute of Chemistry Leiden University Einsteinwegg 55 2300 RA Leiden Netherlands
3. Department of Medicinal Biochemistry, Leiden Institute of Chemistry Leiden University Einsteinwegg 55 2300 RA Leiden Netherlands