Glycine betaine

Trimethylglycine

Names
IUPAC name 2-trimethylammonioacetate
Other names Betaine TMG glycine betaine N,N,N-trimethylglycine
Identifiers
CAS Number	107-43-7 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:17750 N
ChemSpider	242 Y
DrugBank	DB06756 N
ECHA InfoCard	100.003.174
IUPHAR/BPS	4550
MeSH	Betaine
PubChem CID	247
UNII	3SCV180C9W Y
InChI InChI=1S/C5H11NO2/c1-6(2,3)4-5(7)8/h4H2,1-3H3 Y Key: KWIUHFFTVRNATP-UHFFFAOYSA-N Y InChI=1/C5H11NO2/c1-6(2,3)4-5(7)8/h4H2,1-3H3 Key: KWIUHFFTVRNATP-UHFFFAOYAI
SMILES C[N+](C)(C)CC(=O)[O-]
Properties
Chemical formula	C5H11NO2
Molar mass	117.146
Appearance	White solid
Melting point	180 °C (356 °F; 453 K) (decomposes)
Solubility in water	Soluble
Solubility	Methanol
Acidity (pKa)	1.84
Pharmacology
ATC code	A16AA06 (WHO)
License data	EU EMA: by Betaine anhydrous
Related compounds
Related amino acids	Glycine Methylglycine Dimethylglycine
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Trimethylglycine (TMG) is an amino acid derivative that occurs in plants. Trimethylglycine was the first betaine discovered; originally it was simply called betaine because, in the 19th century, it was discovered in sugar beets. Since then, many other betaines have been discovered, and the more specific name glycine betaine distinguishes this one.

Trimethylglycine is an N-trimethylated amino acid. This quaternary ammonium exists as the zwitterion at neutral pH. Strong acids such as hydrochloric acid convert TMG to various salts, with HCl yielding betaine hydrochloride:

Demethylation of TMG gives dimethylglycine. Degradation of TMG yields trimethylamine, the scent of putrefying fish.

Processing sucrose from sugar beets yields glycine betaine as a byproduct. The value of the TMG rivals that of the sugar content in sugar beets.

In most organisms, glycine betaine is biosynthesized by oxidation of choline in two steps. The intermediate, betaine aldehyde, is generated by the action of the enzyme mitochondrial choline oxidase (choline dehydrogenase, EC 1.1.99.1). Betaine aldehyde is further oxidised in the in mice to betaine by the enzyme betaine aldehyde dehydrogenase (EC 1.2.1.8). In humans betaine aldehyde activity is performed by a nonspecific cystosolic aldehyde dehydrogenase enzyme (EC 1.2.1.3)

TMG is an organic osmolyte that occurs in high concentrations (~10 mM) in many marine invertebrates, such as crustaceans and molluscs. It serves as a potent appetitive attractant to generalist carnivores such as the predatory sea-slug Pleurobranchaea californica.