Valeric acid or pentanoic acid is a straight-chain

alkyl In organic chemistry, an alkyl group is an alkane missing one hydrogen. The term ''alkyl'' is intentionally unspecific to include many possible substitutions. An acyclic alkyl has the general formula of . A cycloalkyl is derived from a cycloal ...

carboxylic acid In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is or , with R referring to the alkyl, alkenyl, aryl, or other group. Carboxyl ...

with the

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...

. Like other low-molecular-weight carboxylic acids, it has an unpleasant odor. It is found in the perennial flowering plant ''

Valeriana officinalis Valerian (''Valeriana officinalis'', Caprifoliaceae) is a perennial flowering plant native to Europe and Asia. In the summer when the mature plant may have a height of , it bears sweetly scented pink or white flowers that attract many fly specie ...

'', from which it gets its name. Its primary use is in the synthesis of its

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ...

Salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quanti ...

s and

s of valeric acid are known as valerates or pentanoates. Volatile esters of valeric acid tend to have pleasant odors and are used in perfumes and cosmetics. Several, including ethyl valerate and pentyl valerate are used as food additives because of their fruity flavors.

History

Valeric acid is a minor constituent of the perennial flowering plant valerian (''Valeriana officinalis''), from which it gets its name. The dried root of this plant has been used medicinally since antiquity. The related isovaleric acid shares its unpleasant odor and their chemical identity was investigated by oxidation of the components of fusel alcohol, which includes the five-carbon amyl alcohols. Valeric acid is one volatile component in swine manure. Other components include other carboxylic acids, skatole,

trimethyl amine Trimethylamine (TMA) is an organic compound with the formula N(CH3)3. It is a colorless, hygroscopic, and flammable tertiary amine. It is a gas at room temperature but is usually sold as a 40% solution in water. (It is also sold in pressurized ...

, and isovaleric acid. It is also a flavor component in some foods.

Manufacture

In industry, valeric acid is produced by the oxo process from 1-butene and

syngas Syngas, or synthesis gas, is a mixture of hydrogen and carbon monoxide, in various ratios. The gas often contains some carbon dioxide and methane. It is principly used for producing ammonia or methanol. Syngas is combustible and can be used as ...

, forming valeraldehyde, which is oxidised to the final product. :H₂ + CO + CH₃CH₂CH=CH₂ → CH₃CH₂CH₂CH₂CHO → valeric acid It can also be produced from biomass-derived sugars via levulinic acid and this alternative has received considerable attention as a way to produce

biofuels Biofuel is a fuel that is produced over a short time span from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels, such as oil. According to the United States Energy Information Administration (E ...

Reactions

Valeric acid reacts as a typical carboxylic acid: it can form

amide In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula , where R, R', and R″ represent organic groups or hydrogen atoms. The amide group is called a peptide bond when it is ...

, anhydride, and

chloride The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride s ...

derivatives. The latter, valeryl chloride is commonly used as the intermediate to obtain the others.

Uses

Valeric acid occurs naturally in some foods but is also used as a food additive. Its safety in this application was reviewed by an FAO and WHO panel, who concluded that there were no safety concerns at the likely levels of intake. The compound is used for the preparation of derivatives, notably its volatile esters which, unlike the parent acid, have pleasant odors and fruity flavors and hence find applications in perfumes, cosmetics and foodstuffs. Typical examples are the methyl valerates, ethyl valerates, and pentyl valerates.

Biology

In humans, valeric acid is a minor product of the gut microbiome and can also be produced by metabolism of its esters found in food. The restoration of levels of this acid in the gut has been suggested as the mechanism that results in control of ''Clostridioides difficile'' infection after

fecal microbiota transplant Fecal microbiota transplant (FMT), also known as a stool transplant, is the process of transferring fecal bacteria and other microbes from a healthy individual into another individual. FMT is an effective treatment for ''Clostridioides diffici ...

Valerate salts and esters

The valerate, or pentanoate, ion is C₄ H₉C OO⁻, the conjugate base of valeric acid. It is the form found in biological systems at physiological pH. A valerate, or pentanoate, compound is a carboxylate salt or ester of valeric acid. Many

steroid A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and ...

-based pharmaceuticals, for example ones based on betamethasone or

hydrocortisone Hydrocortisone is the name for the hormone cortisol when supplied as a medication. Uses include conditions such as adrenocortical insufficiency, adrenogenital syndrome, high blood calcium, thyroiditis, rheumatoid arthritis, dermatitis, a ...

, include the steroid as the valerate ester.

Examples

* Methyl valerate * Ethyl valerate * Pentyl valerate *

Betamethasone valerate Betamethasone valerate is a synthetic glucocorticoid ester. It is the 17-valerate ester of betamethasone. Betamethasone valerate is often used to treat mild eczema with good efficacy and lower incidence of steroid induced adverse effects due to ...

* Estradiol valerate *

Hydrocortisone valerate Hydrocortisone valerate is a synthetic glucocorticoid corticosteroid Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main class ...

* Testosterone valerate

References

{{Authority control GABA analogues Fatty acids Alkanoic acids Foul-smelling chemicals