Sarcosine


Sarcosine, also known as N-methylglycine, is an intermediate and byproduct in glycine synthesis and degradation. Sarcosine is metabolized to glycine by the enzyme sarcosine dehydrogenase, while glycine-N-methyl transferase generates sarcosine from glycine. Sarcosine is an amino acid derivative that is naturally found in muscles and other body tissues. In the laboratory, it may be synthesized from chloroacetic acid and methylamine. Sarcosine is found naturally as an intermediate in the metabolism of choline to glycine. Sarcosine is sweet to the taste and dissolves in water. It is used in manufacturing biodegradable surfactants and toothpastes as well as in other applications.
Sarcosine is ubiquitous in biological materials and is present in such foods as egg yolks, turkey, ham, vegetables, legumes, etc.
Sarcosine, like the related compounds dimethylglycine and trimethylglycine, is formed via the metabolism of nutrients such as choline and methionine, which both contain methyl groups 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, creatine, purines and serine. The concentration of sarcosine in blood serum of normal human subjects is 1.4 ± 0.6 micromolar.

Clinical significance

Toxicity

Motor impairment and respiratory issues have been observed in rats at 10mg/kg.
This equates to 800mg for an 80kg person.

Schizophrenia

Sarcosine has been investigated in relation to schizophrenia. Early evidence suggests that intake of 2 g/day sarcosine as add-on therapy to certain antipsychotics in schizophrenia gives significant additional reductions in both positive and negative symptomatology as well as the neurocognitive and general psychopathological symptoms that are common to the illness. Sarcosine had been tolerated well. It is also under investigation for the possible prevention of schizophrenic illness during the prodromal stage of the disease. It acts as a type 1 glycine transporter inhibitor and a glycine agonist. It increases glycine concentrations in the brain thus causing increased NMDA receptor activation and a reduction in symptoms. As such, it might be an interesting treatment option and a possible new direction in the treatment of the mental illness in the future. A 2011 meta-analysis found adjunctive sarcosine to have a medium effect size for negative and total symptoms.

Depression

Major depressive disorder is a complex disease and most currently available antidepressants aiming at monoamine neurotransmission exhibit limited efficacy and cognitive effects. N-methyl-D-aspartate receptors, one subtype of glutamate receptor, play an important role in learning and memory, and NMDAR enhancing agents, such as sarcosine, have been used as adjunctive therapy of schizophrenia. Preliminary clinic trials indicated that intake of sarcosine improved not only psychotic but also depressive symptoms in patients with schizophrenia, and so may also be a useful supplement for treating depressive type schizoaffective disorders where rapid-acting glutamatergic antidepressants, particularly NMDA antagonists such as esketamine, can promote worsening of psychotic features.

Possible marker for prostate cancer

Sarcosine was reported to activate prostate cancer cells and to indicate the malignancy of prostate cancer cells when measured in urine. Sarcosine was identified as a differential metabolite that was greatly increased during prostate cancer progression to metastasis and could be detected in urine. Sarcosine levels seemed to control the invasiveness of the cancer.
This conclusion has been disputed.

History

Sarcosine was first isolated and named by the German chemist Justus von Liebig in 1847.
Jacob Volhard first synthesized it in 1862 while working in the lab of Hermann Kolbe. Prior to the synthesis of sarcosine, it had long been known to be hydrolysis product of creatine, a compound found in meat extract. Under this assumption, by preparing the compound with methylamine and monochloroacetic acid, Volhard proved that sarcosine was N-methylglycine.