Betaine

The original betaine, N,N,N-trimethylglycine, was named after its discovery in sugar beet (Beta vulgaris subsp. vulgaris) in the nineteenth century.

It is a small N-trimethylated amino acid. It is a zwitterion, which cannot isomerize because there is no labile hydrogen atom attached to the nitrogen atom. This substance may be called glycine betaine to distinguish it from other betaines.

Glycine betaine, once taken up by the cell, can be further metabolized through processes such as conversion to dimethylglycine and methionine, which can fuel methylation throughout the cell
Boysen et al. 2022 Environ Microbiol. 24(5): 2380-2403

Betaine is also highly abundant in whe…