About the Authors
Intervet Innovation GmbH, Schwabenheim, Germany
Institute of Organic Chemistry, University of Mainz, Mainz, Germany
The authors have declared that no competing interests exist.
Conceived and designed the experiments: HS CM. Performed the experiments: TM HS SF HB DS. Analyzed the data: HS SF DS CM. Contributed reagents/materials/analysis tools: TM HB. Wrote the paper: TM SF CM.