Nicotinamide

Sirtuin

122.12

DMSO : 23 mg/mL (188.3 mM)
Ethanol : 23 mg/mL (188.3 mM)
Water : 22 mg/mL (180.2 mM)

白色针状结晶或结晶性粉末

Nicotinamide strongly inhibits yeast silencing, increases rDNA recombination, and shortens replicative life span to that of a sir2 mutant. Nicotinamide abolishes silencing and leads to an eventual delocalization of Sir2 even in G(1)-arrested cells, demonstrating that silent heterochromatin requires continual Sir2 activity. Nicotinamide results in a twofold increase in DNA content and a threefold increase in insulin content in the fetal cells. Nicotinamide induces differentiation and maturation of human fetal pancreatic islet cells. Nicotinamide regulates sirtuins by switching between deacetylation and base exchange. Nicotinamide switching is quantitated for the Sir2s from Archeaglobus fulgidus (Sir2Af2), Saccharomyces cerevisiae (Sir2p), and mouse (Sir2alpha). Nicotinamide selectively reduces a specific phospho-species of tau (Thr231) that is associated with microtubule depolymerization in Alzheimer's disease transgenic mice, in a manner similar to inhibition of SirT1. Nicotinamide also dramatically increases acetylated alpha-tubulin, a primary substrate of SirT2, and MAP2c in Alzheimer's disease transgenic mice, both of which are linked to increased microtubule stability. Nicotinamide fosters DNA integrity and maintains phosphatidylserine membrane asymmetry to prevent cellular inflammation, cellular phagocytosis and vascular thrombosis. Nicotinamide both prevents and reverses neuronal and vascular cell injury.

In the mouse, nicotinamide given i.p. at doses of 100-500 mg/kg showed biphasic elimination with dose-dependent changes in half-life. The initial half-life increased significantly (P .

烟酰胺；Niacinamide；Nicotinic acid amide； Vitamin B3

C₆H₆N₂O

98-92-0