The phenylacetic acid is a solid organic compound whose chemical formula is C8H8ORtwo or C6H5CHtwoCOtwoH. It is a monocarboxylic acid, that is, it has a single carboxyl group -COOH.
It is also known as benzeneacetic acid or phenylethanoic acid. It is a white crystalline solid with an unpleasant odor, however, its taste is sweet. It is present in some flowers, fruits and plants, in fermented beverages such as tea and cocoa. It is also found in tobacco and wood smoke.
Phenylacetic acid is a compound that is formed by the transformation of endogenous molecules of some living beings, that is, of molecules that are a natural part of these.
It fulfills important functions which depend on the type of organism in which it is found. For example, in plants it is involved in their growth, while in humans it is involved in the release of important molecular messengers from the brain.
Its effects as an antifungal agent and as an inhibitor of bacterial growth have been studied..
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The phenylacetic or benzeneacetic acid molecule has two functional groups: the carboxyl -COOH and the phenyl C6H5-.
It is like an acetic acid molecule to which a benzene ring or phenyl group has been added. C6H5- in the methyl group -CH3.
It can also be said that it is like a toluene molecule in which a hydrogen H of the methyl group -CH3 has been replaced by a carboxyl group -COOH.
- Phenylacetic acid
- Benzeneacetic acid
- 2-phenylacetic acid
- Phenylethanoic acid
- Benzylformic acid
- Alpha-toluic acid
- Benzylcarboxylic acid.
White to yellow solid in the form of crystals or flakes with an unpleasant, pungent odor.
136.15 g / mol
76.7 ºC
265.5 ºC
132 ºC (closed cup method)
543 ºC
1.09 g / cm3 at 25 ºC
Very soluble in water: 17.3 g / L at 25 ºC
Very soluble in ethanol, ethyl ether and carbon disulfide. Soluble in acetone. Slightly soluble in chloroform.
Its aqueous solutions are weakly acidic.
pKto = 4.31
It has a very unpleasant odor. When diluted in water, it has a sweetish smell similar to honey..
Its taste is sweet similar to honey.
When heated to decomposition it emits acrid and irritating smoke.
Prepared by reacting benzyl cyanide with dilute sulfuric or hydrochloric acid.
Also by reacting benzyl chloride and water in the presence of a Ni (CO) catalyst4.
It acts as a metabolite (a molecule that participates in metabolism, either as a substrate, an intermediate compound or as a final product) in living beings, for example, in humans, in plants, in the Escherichia coli, on Saccharomyces cerevisiae, and in the Aspergillus. However, apparently it is not generated in the same way in all of them.
Phenylacetic acid is the main metabolite of 2-phenylethylamine, which is an endogenous constituent of the human brain and is involved in cerebral transmission.
The metabolism of phenylethylamine leads to its oxidation through the formation of phenylacetaldehyde, which is oxidized to phenylacetic acid..
Phenylacetic acid acts as a neuromodulator as it stimulates the release of dopamine, which is a molecule that performs important functions in the nervous system..
It has been reported that in affective disorders, such as depression and schizophrenia, there are changes in the levels of phenylethylamine or phenylacetic acid in biological fluids..
Variation in the concentration of these compounds has also been suspected of influencing the attention deficit hyperactivity syndrome suffered by some children..
Several researchers have shown that phenylacetic acid is widely distributed in vascular and non-vascular plants..
For more than 40 years it has been recognized as a natural phytohormone or auxin, that is, a hormone that regulates plant growth. Has a positive effect on the growth and development of plants.
It is generally located on the shoots of plants. Its beneficial action on corn, oat, beans (peas or beans), barley, tobacco and tomato plants is known..
However, its mechanism of action in plant growth has not yet been well clarified. It is also not known with certainty how it is formed in plants and vegetables. It has been suggested that in them it is produced from phenylpyruvate.
Others suggest that it is a deamination product of the amino acid phenylalanine (2-amino-3-phenylpropanoic acid) and that phenylalanine-producing plants and microorganisms can generate phenylacetic acid from it..
Some microbes can use it in their metabolic processes. For example the fungus Penicillium chrysogenum you use it to produce penicillin G or natural penicillin.
Others use it as the sole source of carbon and nitrogen, such as Ralstonia solanacearum, a soil bacterium that causes plant wilt like tomato.
Phenylacetic acid has proven to be an effective antifungal agent for agricultural applications.
In some studies it has been found that the phenylacetic acid produced by the bacteria Streptomyces humidus and isolated in the laboratory is effective to inhibit the germination of zoospores and the mycelial growth of the fungus Phytophthora capsici that attacks pepper plants.
It can induce resistance to these plants against the infection of P. capsici, it works as well as other commercial fungicides.
Other studies show that phenylacetic acid produced by various types of Bacillus exerts a toxic effect against the nematode that attacks pine wood.
It is used as a flavoring agent, as it has a caramel, floral, honey flavor.
It is used to make other chemicals and perfumes, to prepare esters that are used as perfumes and flavorings, pharmaceutical compounds and herbicides.
Phenylacetic acid has a use that can be highly harmful, which is to obtain amphetamines, stimulant drugs that generate addiction, for which it is subject to strict control by the authorities of all countries..
In some studies, the accumulation of phenylacetic acid has been found to decrease the cytotoxicity of Pseudomonas aeruginosa in human and animal cells and tissues. This bacteria causes pneumonia.
This accumulation of phenylacetic acid occurs when a high concentration of these microorganisms is inoculated into the human test cells..
The findings suggest that the bacteria P. aeruginosa, under the conditions of the experiences, it produces and accumulates this inhibitor, which counteracts the infection.
The accumulation of phenylacetic acid that occurs in patients with chronic renal failure has been determined to contribute to an increase in atherosclerosis and the rate of cardiovascular disease in them..
Phenylacetic acid strongly inhibits the enzyme that regulates the formation of nitric oxide (NO) from L-arginine (an amino acid).
This generates imbalances at the level of the walls of the arteries, since under normal conditions nitric oxide exerts a protective effect against the formation of atherogenic plaques on the vascular walls..
This imbalance leads to high plaque generation and cardiovascular disease in these at-risk patients..
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