1. Department of Chemistry, University of California, Davis, Davis, California 95616, United States
2. Department of Chemistry, Washington State University, Pullman, Washington 99164, United States
3. NMR Facility, University of California, Davis, Davis, California 95616, United States
4. Department of Biochemistry and Molecular Biology, Yamagata University Graduate School of Medical Science, Yamagata 990-9585, Japan
5. Central Laboratory for Research and Education, Yamagata University Faculty of Medicine, Yamagata 990-9585, Japan