| NMR conditions | Approximately 1 mL of DMSO-d₆ with deuterium chloride addition at room temperature for solubility of precipitate, unless otherwise noted |
|---|---|
| ¹H NMR (500 MHz instrument), increasing molar ratios of uranyl nitrate:NADH | Progressive peak broadening with selective signal loss and chemical shift perturbations. There appears to be broadening in the 3–5 ppm region, indicative of the ribose sugar and phosphate-adjacent protons, where broadening and coalescence of peaks occurred with a loss of fine splitting patterns. Broadening of peaks in the 5–6 ppm anomeric region that disappear upon dilution of uranyl nitrate |
| ¹³C NMR (500 MHz instrument), NADH alone and 1:100 UN:NADH | Peak positions were largely conserved, with small emergences of new carbon resonances. Intensity changes and minor chemical shift perturbations were observed in the ribose region (~60–90 ppm), while two carbonyl-region signals (~150+ ppm) disappeared in the presence of uranyl nitrate |
| ³¹P NMR (400 MHz instrument), conditions | Probe temperature 25 °C; inverse-gated decoupling |
| ³¹P NMR reporting references | Chemical shifts are reported on the δ scale downfield from tetramethylsilane (TMS; 0 ppm). ³¹P chemical shifts were expressed in parts per million from 85 % H₃PO₄ as an external reference |
| ³¹P NMR, NADH alone and after uranyl nitrate addition | NADH alone had a single strong resonance at δ = −11.78 ppm, corresponding to the symmetric pyrophosphate bond. For an equimolar uranyl nitrate:NADH mixture, the abstract reports that the signal shifted from −11.78 ppm to values near 0 ppm. The results report that after uranyl nitrate addition it shifted markedly downfield to δ = ~10 ppm and evolved into multiple peaks. The phosphorus nuclei were no longer magnetically equivalent |
| NMR, concentration series | Continuous, concentration-dependent evolution of all NMR signals without the appearance of distinct sets of free and bound resonances indicates that the system operates in an intermediate exchange regime on the NMR timescale |
Phillip H. Kalaniopio, Matthew C. Salanga. “Implications for dinucleotide cofactor complexation as a novel mechanism of uranium chemical toxicity.” ChemRxiv (). https://doi.org/10.26434/chemrxiv.15007665/v1
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