Nicotinamide riboside

Nicotinamide riboside (NR, SR647) is a pyridine-nucleoside similar to vitamin B3, functioning as a precursor to nicotinamide adenine dinucleotide or NAD+.
Chemistry.
While the molecular weight of nicotinamide riboside is 255.25 g/mol, that of its chloride salt is 290.70 g/mol. As such, 100 mg of nicotinamide riboside chloride provides 88 mg of nicotinamide riboside.
History.
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. "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.
Synthesis.
Different biosynthetic pathways are responsible for converting the different B3 vitamins into NAD+. The enzyme nicotinamide phosphoribosyltransferase (Nampt) catalyzes the rate-limiting step of the two-step pathway converting nicotinamide to NAD+. NR kinase enzymes can also function as a salvage pathway for NAD+, but this pathway is not essential.
Commercialization.
ChromaDex licensed patents in July 2012, and began to develop a process to bring NR to market. ChromaDex has been in a patent dispute with Elysium Health over the rights to nicotinamide riboside supplements.<ref name="CEN_8/19/2018"></ref>
Biosynth Carbosynth licensed a patent to produce new NR salts . The new carboxylic acid salts in crystalline form can be used in nutritional supplements and pharmaceutical compositions.