Glycine betaine structure

The structural similarity between arsenobetaine and glycine betaine suggested that arsenic may substitute for nitrogen in pathways of phospholipid biosynthesis and was the basis for a proposed biogenetic pathway for arsenobetaine (174). The proposed pathway begins with arsenic present as either arsenoethanolamine or arsenocholine. However, the origin of these two compounds is not discussed, and there has been no experimental evidence to support the hypothesis. 

It is still not clear why arsenobetaine should occur at such high levels in marine animals relative to freshwater and terrestrial animals. The structural similarity of arsenobetaine to the important osmolyte glycine betaine suggests that it may be utilized in some osmotic role within marine animals (18). 

Figure 1 Molecular structure of the osmolyte glycine betaine and its analog arsenobetaine.

Batainas widely occurring biogenic amines. The simplest is betaine (glycine betaine), (CH3)3N -CHjCOO- [M, 117.2, m.p. of hydrochloride 227-228 °C (d.)]. B. are synthesized in the ethanolamine cycle, and are metabolically related to mono- and di-methylglycine. They can serve as methyl donors in methylation. The betaine structure, which characterizes all betaines, is the peralkylated zwitterionic form, R3N -CHR -C00-. 

Alkaloids include glycine betaine in E. purpurea The pyrrolizidine alkaloids tussilagine (0.006%) and isotussilagine have been identified in E. angustifolia and E. purpurea dried roots, neither of which possesses a 1,2-unsaturated necine ring structure associated with hepatotoxicity therefore, they are not considered to be problematic. A summary of the chemical composition of E. angustifolia, E. pallida, and E. purpurea can be found in the recent review by Barnes et al. and elsewhere. ... 

The two most common betaines found in plants, glycine betaine and trigonelline, have no asymmetric carbon atom. The betaine of tryptophan, hypaphorine, has only been found in the l form. Ackermann (1913a,b) isolated from meat extract a base which was possibly hexa-methylomithine and whose rotation was found to be opposite to that of the betaine of L-omithine however, the structure of this substance has never been satisfactorily established. The betaine of proline, stachy-drine, was first isolated from Stachys roots and orange leaves in the... 

Glycine is present abundantly in scleroproteins (fibrous protein cf. Chapt. IV-3). Methylation yields sarcosine, which occurs in several peptides. Further methyla-tion yields betain. This substance exists exclusively in the zwitterionic or salt form (zwitterionic formulas sometimes are called betain structures). 

The NPN fraction contains other interesting compounds, such as small peptides. Most of them contribute to flavor besides this, they have a powerful antioxidant activity. Betaines are a special group of compounds that contribute to the specific flavors of different aquatic organisms homarine in lobster and glycine-betaine, butiro-betaine, and arsenic-betaine in crustaceans. Arsenic-betaine has the property of fixing arsenic into the structure, giving a useful method for studying water contamination. 

Miller, J. W Kleven, D. T., Domin, B. A., and Fremau Jr., R. T. (1997) Cloned sodium-land chloride-) dependent high affinity transporters for GABA, glycine, proline, betaine, taurine, and creatine, in Neurotransmitter Transporters Structure, Function, and Regulation (Reith, M. E. A., ed.). Humana Press, Totowa, NJ, pp. 101-150. 

Betaine, or trimethyl glycine, is a naturally occurring zwitterionic nutrient that was first discovered in beets but occurs in a wide variety of plants and animals. Surfactant betaines are structurally analogous compounds but they are manufactured synthetically. 

The DAT, NET, and SERT are members of the family of Na+, Cl -dependent substrate-specific neuronal membrane transporters, which includes transporters for GABA, glycine, taurine, proline, betaine, and creatine (4-8). The putative structure of these transporters consists of 12 transmembrane domains with both the N- and C-terminal domains located within the cytoplasm. The mechanism of the transporter-mediated uptake of monoamines is believed to involve an electrogenic transport of monoamines by sequential binding and cotransport of Na+ and Cl-ions (4-8). 

Replacing one methyl group in A,A,A-trimethyl-glycine by a long alkyl chain gives the simple structure of an alkyl betaine surfactant (Figure 15.3). 

Molecular dynamics of metabolites are important for their interactions and functions. To understand the structural dependence of molecular dynamics for N-methylated glycines, Huang et al. have measured the and H spin-lattice relaxation times for sarcosine, N,N-dimethylglycine, betaine and betaine hydrochloride over a temperature range of 178-460... 

Any of the structures derived from sodium chloroacetate can be called glyci-nates, since they are derivatives of the aminoacid glycine. They can also be called acetates although that name is more common for the amphoteric AM. There are two forms of the AM—the one shown in Figure 7 where 1 mole of SCA is used, and the diacetate where a second mole of SC A converts the AM to a betaine. The AM-SF can be called a propionate as it is a derivative of propionic acid. 

---