NMN, the full name of nicotinamide mononucleotide, is a naturally occurring nucleotide with biological activity. NMN has two irregular forms, α and β; the β isomer is the active form of NMN with a molecular weight of 334.221 g/mol and a chemical formula of C11H15N2O8P, which is a key intermediate in the synthesis of coenzyme---NAD+.

NMN is an inherent substance in the human body and is also rich in some fruits and vegetables. Because nicotinamide belongs to vitamin b3, NMN belongs to the category of vitamin b derivatives. It is widely involved in many biochemical reactions of the human body and is closely related to immunity and metabolism.

Both NMN and NR are precursors of coenzyme NAD+, derivatives of vitamin B3. The relationship between the three is as follows:

• NR: Nicotinamide Riboside, also known as Niagen, nicotinamide riboside

• NMN: Nicotinamide mononucleotide, Nicotinamide mononucleotide

• NAD+: Nicotinamide adenine dinucleotide

  

NMN is the precursor of NAD+, and its function is mainly reflected by NAD+, so we must first explain NAD+:

NAD+, also known as coenzyme I, the full name of nicotinamide adenine dinucleotide, is widely distributed in all cells of the human body, participates in thousands of biocatalytic reactions, and is an indispensable coenzyme in the human body.

The specific reactions that NAD+ participates in mainly include the following: growth, DNA repair (mediated by PARPs), SIRTs protein, and NADP(H) synthesis.

Therefore, NMN supplementation increases the NAD+ content in the body, thereby delaying, improving, and preventing various phenotypes associated with aging, or age-induced metabolic disorders, senile diseases, etc.

• Physiological function: In mammals, β-nicotinamide mononucleotide is generated from nicotinamide (Nicotinamide, Nam) under the catalysis of Nampt (a protease in vivo), and then nicotinamide mononucleotide is synthesized in nicotinamide mononucleotide. NAD+ is generated under the catalysis of nuclear Chemicalbook adenosyltransferase. Nicotinamide mononucleotide is a direct way to replenish NAD+. It is precisely by significantly enhancing the repair ability of DNA damage in cells that nicotinamide mononucleotide finally achieves the effect of reversing aging.

• Anti-aging effect: β-nicotinamide mononucleotide is the precursor of the cofactor NAD+ of longevity protein in the human body. NAD+ is an important coenzyme in the tricarboxylic acid cycle, promoting the metabolism of sugar, fat, and amino acids, and participating in the synthesis of energy; NAD+ is also the only substrate for coenzyme I consuming enzymes (the only substrate for the DNA repair enzyme PARP, the only substrate for the longevity protein SirtuChemicalbookins) Substrate, the only substrate for cyclic ADP ribose synthase CD38/157). NAD+ is involved in all aspects of human metabolism and is a key coenzyme. Without NAD+, metabolism will slow down. By supplementing NAD+, it can comprehensively resist aging.

• Enhance endurance: NMN promotes fat breakdown and increases exercise endurance; NAD+ supplementation increases skeletal muscle form and mitochondrial oxidative metabolism.

• Protect the nervous system: NMN can reduce brain cell death and oxidative stress.

• Cardiovascular protection: NMN can increase the level of NAD+ in the heart and reduce the damage to the heart.

• Hangover and liver protection: NMN can promote alcohol metabolism and enhance the body's tolerance to alcohol.

• Protect vision: NMN can prevent photoreceptor cell degeneration and restore vision, saving retinal disorders.

• Hearing protection: NMN increases NAD+ levels in neurons and tissues of the ear, thereby preventing trauma-induced hearing loss Provide protection.

How to supplement NMN needs to understand the metabolic pathway of NAD+. NAD+ has 3 metabolic pathways in the body, and four types of substances can be finally converted into NAD+.

• Preiss-Handler pathway: This pathway starts from nicotinic acid, is catalyzed by nicotinic acid phosphoribosyltransferase (NAPRT) into nicotinic acid mononucleotide, and catalyzed by NMNATI1~3 enzymes to nicotinic acid adenine dinucleotide Nucleotides are then catalyzed into NAD+.

• De novo synthesis pathway The pathway: also known as the kynurenine pathway. Starting from tryptophan ingested in food, it goes through N-formylkynurenine, L-kynurenine, 5-hydroxy-2-aminobenzoic acid, and ACMS in turn into quinolinic acid, and then quinolinic acid Enter the Preiss-Handler pathway. The IDO and TDO pathways for the conversion of tryptophan to N-formylkynurenine are the limiting steps in the de novo synthesis pathway, and ACMS can also enter the tricarboxylic acid cycle.

• Salvage synthesis pathway: NAD+ becomes nicotinamide after three consumption pathways (sirtuins, PARPS, and the CADPR), and then becomes NMN after NAMPT catalysis. NMN is also converted into NAD+ through the catalysis of NMNAT1~3 enzymes. cycle.

  The content of NAD+ is kept in balance under these three independent pathways. The salvage synthesis pathway is the main source of NAD+ in the human body, accounting for 85% of the NAD+ production. From the perspective of supplementing NAD+, there are four types of substances that can be used as alternatives: niacin, niacinamide, tryptophan, and NR/NMN.