1.Nicotinamide riboside, a trace nutrient in foods, is a Vitamin B3 with effects on energy metabolism and neuroprotection
Yuling Chi, Anthony A. Sauve. Wolters Kluwer Health, 2013, 1363-1950
Nicotinamide riboside is a nucleoside, which incorporates nicotinamide and ribose into a single chemical moiety. Nicotinamide riboside naturally occurs in yeast, bacteria, and mammals. The foods most enriched in nicotinamide riboside are not well identified, although yeast-containing food products are presumed natural sources of the compound, and milk-derived products such as whey fractions have been reported to contain the nutrient. The quantities in foods are quite low, and probably do not exceed the low micromolar range. The mechanisms by which nicotinamide riboside is produced in the biological setting are barely studied, especially in mammals. In baker’s yeast, a phosphatase is implicated in the dephosphorylation of nicotinamide mononucleotide to produce nicotinamide riboside. Nicotinamide riboside is secreted by yeast, suggesting it may be a natural product of yeast fermentative actions in foods.
2.Nicotinamide Riboside Ameliorates Hepatic Metaflammation by Modulating NLRP3 Inflammasome in a Rodent Model of Type 2 Diabetes
Hee Jae Lee, Young-Shick Hong, Woojin Jun, Soo Jin Yang. J Med Food 18 (11) 2015, 1207-1213
Nicotinamide riboside (NR), a new form of niacin, is a natural precursor of nicotinamide adenine dinucleotide (NAD+). NR is present in milk and beer. NR is metabolized by two metabolic pathways. The first is a degradative pathway that produces nicotinamide. The second pathway involves NR kinases. Through those pathways, NR is converted to NAD+. NAD+, which is a classical coenzyme for redox reactions, has important roles in cellular metabolismand energy production and is key in age-related diseases by regulation of the silent information regulator 2 (sirtuin) through increased NAD+ concentrations. Nicotinamide (NAM) has therapeutic benefits, which are related to NAD+. However, NAM treatment at high doses brought undesired effects. Recently, it was reported that NR increases cellular NAD+ in mammalian cells.
3.Application of a coupled enzyme assay to characterize nicotinamide riboside kinases
Christian Dolle, Mathias Ziegler. Analytical Biochemistry 385 (2009) 377-379
Nicotinamide adenine dinucleotide (NAD) has versatile functions in all cells. Besides its involvement in energy metabolism it serves important functions as substrate in a variety of cellular signaling reactions. Although the redox reactions do not result in a net consumption of the molecule, the signaling reactions are accompanied by cleavage of NAD+. Therefore, continuous resynthesis of pyridine nucleotides is vital. NR Kinases (Nrks) are nucleoside kinases that are supposed to preferentially generate nicotinamide mononucleotide (NMN) from NR using adenosine triphosphate (ATP) as phosphoryl donor. They have only recently been identified, and two isoforms were shown to exist in humans. The physiological roles and substrate specificities of these enzymes have so far been studied only poorly, partly because of a lack of convenient enzyme assays. High-performance liquid chromatography (HPLC) analyses have been used, for example, to test pyrimidine nucleosides as potential alternative substrates of Nrks. The commonly used method to measure Nrk activity includes, besides NR and ATP as substrates, NMN adenylyl transferase (NMNAT) and alcohol dehydrogenase (ADH).