Sarcosine, also known as ''N''-methylglycine, or monomethylglycine, is a

monopeptide Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called Protein, proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapepti ...

with the formula CH₃N(H)CH₂CO₂H. It exists at neutral pH as the

zwitterion In chemistry, a zwitterion ( ; ), also called an inner salt or dipolar ion, is a molecule that contains an equal number of positively- and negatively-charged functional groups. : With amino acids, for example, in solution a chemical equilibrium wil ...

CH₃N⁺(H)₂CH₂CO₂⁻, which can be obtained as a white, water-soluble powder. Like some amino acids, sarcosine converts to a cation at low pH and an anion at high pH, with the respective formulas CH₃N⁺(H)₂CH₂CO₂H and CH₃N(H)CH₂CO₂⁻. Sarcosine is a close relative of glycine, with a secondary amine in place of the primary amine. Sarcosine is ubiquitous in biological materials. It is used in manufacturing

biodegradable Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegradati ...

surfactants Surfactants are chemical compounds that decrease the surface tension between two liquids, between a gas and a liquid, or interfacial tension between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsion#Emulsifiers , ...

and toothpastes as well as in other applications. Sarcosine is sweet to the taste.

Biochemistry

Sarcosine is an intermediate and byproduct in

glycine Glycine (symbol Gly or G; ) is an amino acid that has a single hydrogen atom as its side chain. It is the simplest stable amino acid (carbamic acid is unstable), with the chemical formula NH2‐ CH2‐ COOH. Glycine is one of the proteinogeni ...

synthesis and degradation. Sarcosine is metabolized to glycine by the enzyme

sarcosine dehydrogenase In enzymology, sarcosine dehydrogenase () is a mitochondrial enzyme that catalyzes the chemical reaction N-demethylation of sarcosine to give glycine. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH gr ...

, while glycine-''N''-methyl transferase generates sarcosine from glycine. Sarcosine is an

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...

derivative that is naturally found in muscles and other body tissues. In the laboratory, it may be synthesized from

chloroacetic acid Chloroacetic acid, industrially known as monochloroacetic acid (MCA), is the organochlorine compound with the formula ClCH2CO2H. This carboxylic acid is a useful building block in organic synthesis. It is a colorless solid. Related compounds ...

and

methylamine Methylamine is an organic compound with a formula of . This colorless gas is a derivative of ammonia, but with one hydrogen atom being replaced by a methyl group. It is the simplest primary amine. Methylamine is sold as a solution in methanol, ...

. Sarcosine is an intermediate in the metabolism of

choline Choline is an essential nutrient for humans and many other animals. Choline occurs as a cation that forms various salts (X− in the depicted formula is an undefined counteranion). Humans are capable of some ''de novo synthesis'' of choline but re ...

. Sarcosine, like the related compounds

dimethylglycine Dimethylglycine (DMG) is a derivative of the amino acid glycine with the structural formula (CH3)2NCH2COOH. It can be found in beans and liver, and has a sweet taste. It can be formed from trimethylglycine upon the loss of one of its methyl groups ...

(DMG) and

trimethylglycine Trimethylglycine 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. It has a sweet and umami ...

(TMG), is formed via the metabolism of nutrients such as

and

methionine Methionine (symbol Met or M) () is an essential amino acid in humans. As the precursor of other amino acids such as cysteine and taurine, versatile compounds such as SAM-e, and the important antioxidant glutathione, methionine plays a critical ro ...

, which both contain

methyl groups In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in many ...

used in a wide range of biochemical reactions. Sarcosine is rapidly degraded to glycine, which, in addition to its importance as a constituent of protein, plays a significant role in various physiological processes as a prime metabolic source of components of living cells such as

glutathione Glutathione (GSH, ) is an antioxidant in plants, animals, fungi, and some bacteria and archaea. Glutathione is capable of preventing damage to important cellular components caused by sources such as reactive oxygen species, free radicals, pero ...

creatine Creatine ( or ) is an organic compound with the nominal formula (H2N)(HN)CN(CH3)CH2CO2H. It exists in various modifications (tautomers) in solution. Creatine is found in vertebrates where it facilitates recycling of adenosine triphosphate ( ...

purine Purine is a heterocyclic compound, heterocyclic aromatic organic compound that consists of two rings (pyrimidine and imidazole) fused together. It is water-soluble. Purine also gives its name to the wider class of molecules, purines, which includ ...

s and

serine Serine (symbol Ser or S) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated − form under biological conditions), a carboxyl group (which is in the deprotonated − form un ...

. The concentration of sarcosine in blood serum of normal human subjects is 1.4 ± 0.6 micromolar.

Surfactants

A variety of surfactants are produced from sarcosine.

Clinical investigations

Sarcosine has been investigated in relation to

schizophrenia Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social withdra ...

. Early evidence suggests that intake of 2 g/day sarcosine as add-on therapy to many

antipsychotics Antipsychotics, also known as neuroleptics, are a class of Psychiatric medication, psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), principally in schizophrenia but ...

except clozapine. Sarcosine has also been debated as a biomarker for prostate cancer cells.

History

Sarcosine was first isolated and named by the German chemist

Justus von Liebig Justus Freiherr von Liebig (12 May 1803 – 20 April 1873) was a German scientist who made major contributions to agricultural and biological chemistry, and is considered one of the principal founders of organic chemistry. As a professor at t ...

in 1847.

Jacob Volhard Jacob Volhard (4 June 1834 – 14 January 1910) was the German chemist who discovered, together with his student Hugo Erdmann, the Volhard–Erdmann cyclization reaction. He was also responsible for the improvement of the Hell–Volhard–Zel ...

first synthesized it in 1862 while working in the lab of

Hermann Kolbe Adolph Wilhelm Hermann Kolbe (27 September 1818 – 25 November 1884) was a major contributor to the birth of modern organic chemistry. He was a professor at Marburg and Leipzig. Kolbe was the first to apply the term synthesis in a chemical cont ...

. Prior to the synthesis of sarcosine, it had long been known to be a hydrolysis product of

, a compound found in meat extract. Under this assumption, by preparing the compound with

and

monochloroacetic acid Chloroacetic acid, industrially known as monochloroacetic acid (MCA), is the organochlorine compound with the formula ClCH2CO2H. This carboxylic acid is a useful building block in organic synthesis. It is a colorless solid. Related compounds ar ...

, Volhard proved that sarcosine was N-methylglycine.

References

{{Use dmy dates, date=April 2017 Glycine reuptake inhibitors Glycine receptor agonists

Biochemistry

Surfactants

Clinical investigations

History

See also

References