Betaine (N,N,N-trimethylglycine, glycine betaine) is an organic nitrogenous compound, found for the first time in sugar beet juice.
It is classified as a methyl-ammonia due to three chemically-active methyl groups bound to the nitrogen atom of a glycine molecule, and it is considered the only readily active methyl-group donor.
Various analogues of glycine betaine exist in plants: proline betaine (stachydrine), trigonelline, arsenobetaine, betonicine, butirobetaine, ergothionine, propionobetaine, and sulfur analogues. The sulfur analogues are several in type: β-alaninebetaine, dimethylsulfonioacetate, andmdimethylsulfoniopropionate (DMSP).
The biosynthesis of betaine is made by the oxidation of choline in the cell mitochondrion. Choline and its derivatives serve as components of structural lipoproteins, blood and membrane lipids, and as a precursor of the neurotransmitter acetylcholine.
The principal physiologic role of betaine is as an osmolyte and methyl donor (transmethylation). As such, it is indispensable to preserve the health of kidneys, liver, and heart. This compound has an important role in preventing and treating many chronic diseases, among which lowering of plasma homocysteine levels has gained the most attention.
High serum homocysteine levels have been associated with increased risk for cardiovascular diseases (stroke, heart attack, atherosclerosis), cancer, peripheral neuropathy, etc.
The osmoprotectant action of betaine ameliorates the effects of heat stress and of acid-base balance changes that may compromise physiological and metabolic functions, and consequently, broiler performance and feed efficiency.
Organic osmolytes of betaine
