Nicotinamide（烟酰胺，又称Vitamin B3），是sirtuins的非竞争性抑制剂，该抑制作用影响体内外多种重要的调控机制。Nicotinamide强烈抑制酵母SIR2介导的转录沉默，增加rDNA重组，并缩短复制寿命。酵母酶PNC1可将nicotinamide转化为烟酸（nicotinic acid），用于激活Sir2，阻止nicotinamide对端粒的抑制作用和rDNA沉默。Nicotinamide抑制p53的去乙酰化反应，并抑制组蛋白H3和H4的去乙酰化反应。Nicotinamide诱导多种肿瘤细胞凋亡，并伴随caspase级联活化反应。

Nicotinamide已用于临床前实验，用于治疗癌症和I型糖尿病。

参考文献

[1] Bitterman KJ, et al. Inhibition of Silencing and Accelerated Aging by Nicotinamide, a Putative Negative Regulator of Yeast Sir2 and Human SIRT1. J Biol Chem, 277(47): 45099-45107 (2002).

[2] Avalos JL, et al. Mechanism of Sirtuin Inhibition by Nicotinamide: Altering the NAD+ Cosubstrate Specificity of a Sir2 Enzyme. 17(6): 855–868 (2005).

[3] Wang T, et al. Nicotinamide-mediated inhibition of SIRT1 deacetylase is associated with the viability of cancer cells exposed to antitumor agents and apoptosis. Oncol Lett. 6(2): 600–604 (2013).

[4] Audrito V, et al. Nicotinamide Blocks Proliferation and Induces Apoptosis of Chronic Lymphocytic Leukemia Cells through Activation of the p53/miR-34a/SIRT1 Tumor Suppressor Network. Cancer Res. 71(13): 4473–4483 (2011).

粉末直接保存于-25~-15℃，有效期2年。建议避光干燥保存，避免反复冻融。