European Community (EC) Number: 200-293-7
Molecular Formula: C5H9NO4
Molecular Weight: 147.13
IUPAC Name: (2S)-2-aminopentanedioic acid
Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins.
Glutamic acid is non-essential in humans, meaning that the body can synthesize it.
Glutamic acid is also an excitatory neurotransmitter, in fact the most abundant one, in the vertebrate nervous system.
Glutamic acid serves as the precursor for the synthesis of the inhibitory gamma-aminobutyric acid (GABA) in GABA-ergic neurons.
Glutamic acid's molecular formula is C5H9NO4.
Glutamic acid exists in three optically isomeric forms; the dextrorotatory l-form is usually obtained by hydrolysis of gluten or from the waste waters of beet-sugar manufacture or by fermentation.
Glutamic acid's molecular structure could be idealized as HOOC−CH(NH2)−(CH2)2−COOH, with two carboxyl groups −COOH and one amino group −NH2.
However, in the solid state and mildly acidic water solutions, the molecule assumes an electrically neutral zwitterion structure −OOC−CH(NH+3)−(CH2)2−COOH.
Glutamic acid is encoded by the codons GAA or GAG.
The acid can lose one proton from its second carboxyl group to form the conjugate base, the singly-negative anion glutamate −OOC−CH(NH+3)−(CH2)2−COO−.
This form of the compound is prevalent in neutral solutions.
The glutamate neurotransmitter plays the principal role in neural activation.
This anion creates the savory umami flavor of foods and is found in glutamate flavorings such as MSG.
In Europe it is classified as food additive E620.
In highly alkaline solutions the doubly negative anion −OOC−CH(NH2)−(CH2)2−COO− prevails.
The radical corresponding to glutamate is called glutamyl.
When glutamic acid is dissolved in water, the amino group (−NH2) may gain a proton (H+), and/or the carboxyl groups may lose protons, depending on the acidity of the medium.
In sufficiently acidic environments, the amino group gains a proton and the molecule becomes a cation with a single positive charge, HOOC−CH(NH+3)−(CH2)2−COOH.
At pH values between about 2.5 and 4.1, the carboxylic acid closer to the amine generally loses a proton, and the acid becomes the neutral zwitterion −OOC−CH(NH+3)−(CH2)2−COOH.
This is also the form of the compound in the crystalline solid state.
The change in protonation state is gradual; the two forms are in equal concentrations at pH 2.10.
At even higher pH, the other carboxylic acid group loses its proton and the acid exists almost entirely as the glutamate anion −OOC−CH(NH+3)−(CH2)2−COO−, with a single negative charge overall.
The change in protonation state occurs at pH 4.07.
This form with both carboxylates lacking protons is dominant in the physiological pH range (7.35–7.45).
At even higher pH, the amino group loses the extra proton, and the prevalent species is the doubly-negative anion −OOC−CH(NH2)−(CH2)2−COO−.
The change in protonation state occurs at pH 9.47.
The carbon atom adjacent to the amino group is chiral (connected to four distinct groups).
Glutamic acid can exist in three optical isomers, including the dextrorotatory l-form, d(−), and l(+).
The l form is the one most widely occurring in nature, but the d form occurs in some special contexts, such as the cell walls of the bacteria (which can manufacture it from the l form with the enzyme glutamate racemase) and the liver of mammals.
Glutamic acid is produced on the largest scale of any amino acid, with an estimated annual production of about 1.5 million tons in 2006.
Chemical synthesis was supplanted by the aerobic fermentation of sugars and ammonia in the 1950s, with the organism Corynebacterium glutamicum (also known as Brevibacterium flavum) being the most widely used for production.
Isolation and purification can be achieved by concentration and crystallization; it is also widely available as its hydrochloride salt.
Function and uses
Glutamate is a key compound in cellular metabolism.
In humans, dietary proteins are broken down by digestion into amino acids, which serve as metabolic fuel for other functional roles in the body.
A key process in amino acid degradation is transamination, in which the amino group of an amino acid is transferred to an α-ketoacid, typically catalysed by a transaminase.
The reaction can be generalised as such:
R1-amino acid + R2-α-ketoacid ⇌ R1-α-ketoacid + R2-amino acid
A very common α-keto acid is α-ketoglutarate, an intermediate in the citric acid cycle.
Transamination of α-ketoglutarate gives glutamate.
The resulting α-ketoacid product is often a useful one as well, which can contribute as fuel or as a substrate for further metabolism processes.
Examples are as follows:
Alanine + α-ketoglutarate ⇌ pyruvate + glutamate
Aspartate + α-ketoglutarate ⇌ oxaloacetate + glutamate
Both pyruvate and oxaloacetate are key components of cellular metabolism, contributing as substrates or intermediates in fundamental processes such as glycolysis, gluconeogenesis, and the citric acid cycle.
Glutamate also plays an important role in the body's disposal of excess or waste nitrogen. Glutamate undergoes deamination, an oxidative reaction catalysed by glutamate dehydrogenase, as follows:
glutamate + H2O + NADP+ → α-ketoglutarate + NADPH + NH3 + H+
Ammonia (as ammonium) is then excreted predominantly as urea, synthesised in the liver.
Transamination can thus be linked to deamination, effectively allowing nitrogen from the amine groups of amino acids to be removed, via glutamate as an intermediate, and finally excreted from the body in the form of urea.
Glutamate is also a neurotransmitter, which makes it one of the most abundant molecules in the brain.
Malignant brain tumors known as glioma or glioblastoma exploit this phenomenon by using glutamate as an energy source, especially when these tumors become more dependent on glutamate due to mutations in the gene IDH1.
Glutamate is the most abundant excitatory neurotransmitter in the vertebrate nervous system.
At chemical synapses, glutamate is stored in vesicles. Nerve impulses trigger the release of glutamate from the presynaptic cell.
Glutamate acts on ionotropic and metabotropic (G-protein coupled) receptors.
In the opposing postsynaptic cell, glutamate receptors, such as the NMDA receptor or the AMPA receptor, bind glutamate and are activated.
Because of its role in synaptic plasticity, glutamate is involved in cognitive functions such as learning and memory in the brain.
The form of plasticity known as long-term potentiation takes place at glutamatergic synapses in the hippocampus, neocortex, and other parts of the brain.
Glutamate works not only as a point-to-point transmitter, but also through spill-over synaptic crosstalk between synapses in which summation of glutamate released from a neighboring synapse creates extrasynaptic signaling/volume transmission.
In addition, glutamate plays important roles in the regulation of growth cones and synaptogenesis during brain development as originally described by Mark Mattson.
Brain nonsynaptic glutamatergic signaling circuits
Extracellular glutamate in Drosophila brains has been found to regulate postsynaptic glutamate receptor clustering, via a process involving receptor desensitization.
A gene expressed in glial cells actively transports glutamate into the extracellular space, while, in the nucleus accumbens-stimulating group II metabotropic glutamate receptors, this gene was found to reduce extracellular glutamate levels.
This raises the possibility that this extracellular glutamate plays an "endocrine-like" role as part of a larger homeostatic system.
Glutamate also serves as the precursor for the synthesis of the inhibitory gamma-aminobutyric acid (GABA) in GABA-ergic neurons.
This reaction is catalyzed by glutamate decarboxylase (GAD), which is most abundant in the cerebellum and pancreas.
Stiff person syndrome is a neurologic disorder caused by anti-GAD antibodies, leading to a decrease in GABA synthesis and, therefore, impaired motor function such as muscle stiffness and spasm.
Since the pancreas has abundant GAD, a direct immunological destruction occurs in the pancreas and the patients will have diabetes mellitus.
Glutamic acid, being a constituent of protein, is present in foods that contain protein, but it can only be tasted when it is present in an unbound form.
Significant amounts of free glutamic acid are present in a wide variety of foods, including cheeses and soy sauce, and glutamic acid is responsible for umami, one of the five basic tastes of the human sense of taste.
Glutamic acid often is used as a food additive and flavor enhancer in the form of its sodium salt, known as monosodium glutamate (MSG).
All meats, poultry, fish, eggs, dairy products, and kombu are excellent sources of glutamic acid.
Some protein-rich plant foods also serve as sources. 30% to 35% of gluten (much of the protein in wheat) is glutamic acid.
Ninety-five percent of the dietary glutamate is metabolized by intestinal cells in a first pass.
Auxigro is a plant growth preparation that contains 30% glutamic acid.
In recent years, there has been much research into the use of residual dipolar coupling (RDC) in nuclear magnetic resonance spectroscopy (NMR).
A glutamic acid derivative, poly-γ-benzyl-L-glutamate (PBLG), is often used as an alignment medium to control the scale of the dipolar interactions observed.
L-glutamic acid is an optically active form of glutamic acid having L-configuration.
L-glutamic acid has a role as a nutraceutical, a micronutrient, an Escherichia coli metabolite, a mouse metabolite, a ferroptosis inducer and a neurotransmitter.
L-glutamic acid is a glutamine family amino acid, a proteinogenic amino acid, a glutamic acid and a L-alpha-amino acid.
L-glutamic acid is a conjugate acid of a L-glutamate(1-).
L-glutamic acid is an enantiomer of a D-glutamic acid.
Glutamic acid is an amino acid used to form proteins.
In the body it turns into glutamate.
This is a chemical that helps nerve cells in the brain send and receive information from other cells.
Glutamic acid may be involved in learning and memory.
Glutamic acid may help people with hypochlorhydria (low stomach acid) or achlorhydria (no stomach acid).
Glutamic acid or glutamate is synthesized from a-ketoglutaric acid, an intermediate in the citric acid cycle, by mitochondrial glutamate dehydrogenase.
Glutamate is also synthesized from glutamine by glutaminase in the central nervous system.
Glutamate is the most abundant excitatory neurotransmitter in the vertebrate nervous systems.
Many synapses use multiple types of glutamate receptors, including ionotropic and metabotropic receptors.
Three types of ionotropic glutamate receptors, AMPA, kainate, and NMDA, and three groups of metabotropic receptors are known.
Glutamatergic synapses in the hippocampus, neocortex, and other parts of the brain have plasticity for long-term potentiation that enables learning and memory.
Glutamate also functions as a spill-over synaptic crosstalk between synapses where released glutamate creates extrasynaptic signaling, named volume transmission.
Glutamate stimulates glutamate-gated chloride channels in nematodes and arthropods.
Although they occur naturally in many foods, the flavor contributions made by glutamic acid and other amino acids were only scientifically identified early in the 20th century.
The substance was discovered and identified in the year 1866 by the German chemist Karl Heinrich Ritthausen, who treated wheat gluten (for which it was named) with sulfuric acid.
In 1908, Japanese researcher Kikunae Ikeda of the Tokyo Imperial University identified brown crystals left behind after the evaporation of a large amount of kombu broth as glutamic acid.
These crystals, when tasted, reproduced the ineffable but undeniable flavor he detected in many foods, most especially in seaweed.
Professor Ikeda termed this flavor umami.
He then patented a method of mass-producing a crystalline salt of glutamic acid, monosodium glutamate.
Glutamic acid is a nonessential amino acid, which is mainly used and produced in the form of its sodium salt as monosodium glutamate (MSG).
Glutamic acid can be found in animal and plant proteins.
In 1908, glutamic acid was identified as the key component in a seaweed extract, which is widely used in the Asian cuisine and was patented and marketed as flavor enhancer in its sodium salt form – MSG – by Ajinomoto Corp. in Japan.
Initially, glutamic acid was produced synthetically but fermentation of glutamic acid was developed in 1957 and is today the common way of production.
The fermentation medium consists of strains of Corynebacteria or Brevibacteria producing the glutamic acid plus carbon sources (glucose and molasses), inorganic salts, and biotin.
Similar to the production of lysine, UF can be used after the fermentation process for the initial separation of the microorganism and the glutamic acid followed by the pre-concentration of glutamic acid containing UF permerate by RO before evaporation and crystallization.
Alternatively, ion exchange can be used for the recovery of glutamic acid and RO can be used as initial concentration step before further processing.
glutamic acid, an amino acid occurring in substantial amounts as a product of the hydrolysis of proteins.
Certain plant proteins (e.g., gliadin) yield as much as 45 percent of their weight as glutamic acid; other proteins yield 10 to 20 percent.
Much of this content may result from the presence of a related substance, glutamine, in proteins; glutamine is converted to glutamic acid when a protein is hydrolyzed.
First isolated in 1865, glutamic acid is an important metabolic intermediate.
It is one of several so-called nonessential amino acids; i.e., animals can synthesize it from oxoglutaric acid (formed in the metabolism of carbohydrates) and do not require dietary sources.
Monosodium glutamate (MSG), a salt of glutamic acid, is sometimes used as a condiment for flavouring foods.
In addition to being one of the building blocks in protein synthesis, it is the most widespread neurotransmitter in brain function, as an excitatory neurotransmitter and as a precursor for the synthesis of GABA in GABAergic neurons.
Glutamic acid: An amino acid, one of the 20 building blocks of protein.
A nonessential amino acid, glutamic acid is present in many animal and plant proteins.
It is involved in ammonia metabolism and serves as a neurotransmitter.
Glutamic acid was isolated from wheat gluten in 1866 and first synthesized in 1890.
Glutamic acid has one additional methylene group in its side chain than does aspartic acid.
The side chain carboxyl of aspartic acid is referred to as the β carboxyl group, while that of glutamic acid is referred to as the γ carboxyl group.
The pKa of the γ carboxyl group for glutamic acid in a polypeptide is about 4.3, significantly higher than that of aspartic acid.
This is due to the inductive effect of the additional methylene group.
In some proteins, due to a vitamin K dependent carboxylase, some glutamic acids will be dicarboxylic acids, referred to as γ carboxyglutamic acid, that form tight binding sites for calcium ion.
Glutamic Acid is comprised of amino group, aliphatic amino acid, α-carboxylic acid and side chain carboxylic acid.
Glutamic acid plays a vital role in the neural activation.
Glutamic acid is one of the 20 amino acids.
There are two types of amino acids, essential amino acids, and non-essential amino acids.
Glutamic acid is a non-essential amino acid that forms proteins.
The chemical formula of Glutamic acid is C5H9O4N.
Uses and Functions of Glutamic Acid:
Metabolism: It plays a vital role in cellular metabolism.
In the human body, dietary proteins are broken down into amino acids by digestion.
Transamination is one of the key processes in amino acid degradation.
Glutamate also plays a vital role in the disposal of excess nitrogen in the human body.
Glutamate + H2O + NADP+ → α-ketoglutarate + NADPH + NH3 + H+
Functioning of Brain: Glutamic acid acts as an energy source for the brain for high functioning and stimulates mental readiness.
Lack of amino acid can lead to attention deficit disorder.
Glutamic acid is recommended by medical practitioners as it helps with behavioral problems and helps in creating improved learning environment.
Functioning of Heart: Monosodium glutamate is a form of a glutamic acid that helps in improving the functions of the heart beat.
Glutamic acid also helps to decrease chest pain associated with coronary heart disease.
Prostate Health: Glutamic acid aids the normal functioning of the prostate.
Naturally, the prostate is comprised of a high concentration of glutamic acid.
Immune System Support and Detoxification: Glutamic acid is necessary for the removal of toxic metabolic wastes products produced by the human body.
Mainly, it essential for detoxifying ammonia which is done by conversion of glutamic acid into glutamine.
Sources of Glutamic Acid:
The prime source of the glutamic acid includes food products with high proteins namely egg, dairy products, fish, meat, and poultry.
These amino acids are also used as an additive to add certain flavors to the products.
Vegetable Sources of glutamic acid include cabbage, beets, spinach, parsley, kale, wheat, and wheatgrass.
All the legumes and beans are very rich in the proteins and contain a significant amount of glutamic acids.
Aluminum L Glutamate
Glutamic Acid, (D)-Isomer
L Glutamic Acid
Glutamic acid, L-
FEMA No. 3285
Pentanedioic acid, 2-amino-, (S)-
EPA Pesticide Chemical Code 374350
Glutamic acid (VAN)
Glutamic acid (H-3)
Glutaminic acid (VAN)
Glutamic Acid (L-glutamic acid)
Glutamic Acid [USAN:INN]
Acide glutamique [INN-French]
Acido glutamico [INN-Spanish]
Acidum glutamicum [INN-Latin]
Glutamic acid, (S)-
alpha-Aminoglutaric acid (VAN)
2-Aminopentanedioic acid, (S)-
Glutamic acid polymer
alpha-L-Glutamic acid polymer
L(+)-Monosodium glutamate monohydrate
L-Glutamic acid (9CI)
Glutamic acid (USP)
L-Glutamic acid (JP17)
L-Glutamic acid, 98.5%
L-Glutamic acid, 99%, FCC
Glutamic acid, L- (7CI,8CI)
L (+)-glutamic acid, alpha-form
L-Glutamic acid, non-animal source
gamma-poly(L-glutamic acid) macromolecule
L-Glutamic acid, BioUltra, >=99.5% (NT)
L-Glutamic acid, tested according to Ph.Eur.
L-Glutamic acid, NIST(R)RM 8573, USGS40
L-Glutamic acid, JIS special grade, >=99.0%
L-Glutamic acid, NIST(R) RM 8574, USGS41
L-Glutamic acid, ReagentPlus(R), >=99% (HPLC)
L-Glutamic acid, Vetec(TM) reagent grade, >=99%
L-Glutamic acid, >=99%, FCC, natural sourced, FG
UNII-0O72R8RF8A component WHUUTDBJXJRKMK-VKHMYHEASA-N
UNII-3KX376GY7L component WHUUTDBJXJRKMK-VKHMYHEASA-N
UNII-61LJO5I15S component WHUUTDBJXJRKMK-VKHMYHEASA-N
Glutamic acid, European Pharmacopoeia (EP) Reference Standard
L-Glutamic acid, certified reference material, TraceCERT(R)
Glutamic acid, United States Pharmacopeia (USP) Reference Standard
L-Glutamic acid, from non-animal source, meets EP testing specifications, suitable for cell culture, 98.5-100.5%
L-Glutamic acid, PharmaGrade, Ajinomoto, EP, manufactured under appropriate GMP controls for Pharma or Biopharmaceutical production, suitable for cell culture