1. The structure and properties of betaine
 
Betaine, also known as trimethylglycine, has a molecular formula of C5H11NO2 and a molecular weight of 117.15. It is a quaternary amine alkaloid. Pure betaine is white crystal with sweet taste and special protein taste; pure betaine is very easy to deliquescence, while hydrochloride is not easy to deliquescence; betaine is non-toxic, and its median lethal dose is 18.14g/kg. The molecular structure of betaine is unique. One is that the distribution of electric charge in the molecule is neutral, and the other is that it contains three active methyl groups. This structural particularity determines the properties of betaine and its use in animal nutrition metabolism. unique features.
 
2. The relationship between betaine, choline and methionine
 
Betaine, choline and methionine can all be used as methyl donors, but methionine and choline must be activated before they can be used as methyl donors. Choline must first be transported into the mitochondria and converted into betaine through a two-step oxidation reaction, so that its methyl group can be easily transferred. Another study showed that, when quantifying the efficacy of homocysteine ​​as a precursor of methionine, it was betaine, but not choline, that enhanced the conversion of homocysteine ​​to methionine. Due to the interference of ionophore anticoccidial drugs and other compounds in the compound feed, the transport system of choline entering the mitochondria is inhibited, so the conversion rate of choline in the mitochondria is extremely low.

3. The mechanism of action of betaine
 
Methyl is an indispensable and important substance for the metabolism of various substances in animals. Animals can hardly synthesize methyl and must be supplied by feed. Betaine is the most effective methyl donor, and all three of its methyl groups can be used as effective active methyl groups. One of them methylates homocysteine ​​to form endogenous methionine and dimethylglycine, endogenous methionine releases methyl group by forming S-adenosylmethionine, and dimethylglycine releases methyl group to form 5-methylglycine 5-methyltetrahydrofolate is a methyl donor for the synthesis of methionine from homocysteine. Betaine participates in the metabolism of proteins, fats and other substances through betaine-homocysteine ​​methyl transfer reaction, and plays an important role in the nervous system, immune system, urinary system and cardiovascular system.