1. Department of Natural Product Biosynthesis, Max Planck Institute of Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany
2. Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
3. Willard Henry Dow Laboratory, Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States