Nicotinamide Riboside Chloride Hygieia NR

Nicotinamide Riboside Chloride is the chloride salt form of nicotinamide riboside(NR).NR is a new form pyridine-nucleoside of vitamin B3 that functions as a precursor to nicotinamide adenine dinucleotide(NAD) or NAD+ . Nicotinamide riboside chloride is a crystal form of Nicotinamide riboside (NR) chloride. Nicotinamide riboside chloride increases NAD[+] levels and activates SIRT1 and SIRT3, culminating in enhanced oxidative metabolism and protection against high fat diet-induced metabolic abnormalities. Nicotinamide riboside chloride is used in dietary supplements.
Nicotinamide riboside chloride (NR-CL) is structurally a quaternary ammonium salt containing a sensitive N-glycosidic bond that spontaneously cleaves in aqueous solution, yielding nicotinamide and d-ribose degradation products (Figure 1). NR-CL exhibits three crystalline forms: Type A, Type B, and Type C. Forms A and B represent true polymorphs of the anhydrous form, whereas form C constitutes a pseudo-polymorphic form as a methanesulfonate solvate. The B form exhibits a higher crystal density (1.591 Mg/m³) and a higher melting/decomposition temperature (123°C) compared to the A form (1.512 Mg/m³, 119°C), making it the most stable crystalline form. The crystal structure of Form B(Figure 2) is orthorhombic P212121 space group, with a = 7.0008(11) Å, b = 9.6465(15) Å, c = 17.971(3) Å, V = 1213.7(3) ų, and Z = 4.
Nicotinamide riboside (NR) was first described in 1944 as a growth factor, termed Factor V, for Haemophilus influenza, a bacterium that lives in and depends on blood. Factor V, purified from blood, was shown to exist in three forms: NAD+, NMN and NR. NR was the compound that led to the most rapid growth of this bacterium.Notably, H. influenza cannot grow on nicotinic acid, nicotinamide, tryptophan or aspartic acid, which were the previously known precursors of NAD+.In 2000, yeast Sir2 was shown to be an NAD+-dependent protein lysine deacetylase, which led several research groups to probe yeast NAD+ metabolism for genes and enzymes that might regulate lifespan. Biosynthesis of NAD+ in yeast was thought to flow exclusively through NAMN (nicotinic acid mononucleotide).When NAD+ synthase (glutamine-hydrolysing) was deleted from yeast cells, NR permitted yeast cells to grow. Thus, these Dartmouth College investigators proceeded to clone yeast and human nicotinamide riboside kinases and demonstrate the conversion of NR to NMN by nicotinamide riboside kinases in vitro and in vivo. They also demonstrated that NR is a natural product found in cow’s milk.