Читать книгу Plant Nucleotide Metabolism - Hiroshi Ashihara - Страница 29

In contrast to pyridine nucleotides, the pool sizes of nicotinate (5) and nicotinamide (6) are very small. These metabolites, produced by pyridine nucleotide degradation, are converted rapidly to trigonelline (7, N-methylnicotinate) or nicotinate glucosides (Ashihara et al. 2015). Typically, when the concentration of niacin, which comprises nicotinamide, nicotinate, and vitamin B₃, is analysed in foodstuffs, the contribution of these individual components is not considered. Common extraction treatments, such as alkaline or acid hydrolysis, mean that any NAD, NADP, nicotinamide, and other nicotinate-related metabolites present in the sample are converted to nicotinate, which is the form that is then measured as niacin (Noctor et al. 2011).