FIGURE 2.

NR binding to milk demonstrated by NMR. Organic and conventional skim milk was separated into soluble and resuspended particulate fractions. NR was added to the nonfractionated milk and to the fractions. NR binding was analyzed with NMR as described. (A, E) Normal 1-dimensional ¹H NMR spectra of NR. (B–D, F–H) WaterLOGSY spectra of NR in the presence of milk. (A) NR alone. (B) NR + total conventional milk. (C) NR + conventional milk (soluble fraction). (D) NR + conventional milk (particulate fraction). (E) NR alone. (F) NR + total organic milk. (G) NR + organic milk (soluble fraction). (H) NR + organic milk (particulate fraction). The assigned ¹H resonances of the nicotinamide ring aromatic protons are labeled. ¹H, proton; NR, nicotinamide riboside; ppm, parts per million; WaterLOGSY, water-ligand observed via gradient spectroscopy.