1. Chemistry Section, Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
2. Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
3. Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States
4. Division of Magnetic Resonance, Korea Basic Science Institute, Cheongju 28119, Republic of Korea