1. Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
2. NMR Laboratory, School of Chemical Sciences, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
3. Department of Chemistry, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
4. Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States