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 cycloalk ...

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. Carboxylic ...

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 ar ...

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 quantitie ...

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 Ethyl pentanoate, also commonly known as ethyl valerate, is an organic compound used in flavors. It is an ester with the molecular formula C7H14O2. This colorless liquid is poorly soluble in water but miscible with organic solvents. As is the c ...

and

pentyl valerate Pentyl pentanoate (C4H9COOC5H11) is an ester used in dilute solution to replicate the scent or flavour of apple, and sometimes pineapple The pineapple (''Ananas comosus'') is a tropical plant with an edible fruit; it is the most economically ...

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 Skatole or 3-methylindole is an organic compound belonging to the indole family. It occurs naturally in the feces of mammals and birds and is the primary contributor to fecal odor. In low concentrations, it has a flowery smell and is found in seve ...

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 1-Butene (or 1-Butylene) is the organic compound with the formula CH3CH2CH=CH2. It is a colorless gas that is easily condensed to give a colorless liquid. It is classified as a linear alpha-olefin. It is one of the isomers of butene (butylene). I ...

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,

, anhydride, and chloride derivatives. The latter,

valeryl chloride Pentanoyl chloride is an acyl chloride derived from pentanoic acid. It is a colorless liquid that is used to attach the valeroyl group. It is usually produced by chlorination of valeric acid. Reactions Like related acyl chlorides, valeryl chlori ...

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 valerate Methyl pentanoate, commonly known as methyl valerate, is the methyl ester of pentanoic acid (valeric acid) with a fruity odor. Methyl pentanoate is commonly used in fragrances, beauty care, soap, laundry detergents at levels of 0.1–1%. In a ...

s, and

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 In organic chemistry, a carboxylate is the conjugate base of a carboxylic acid, (or ). It is an ion with negative charge. Carboxylate salts are salts that have the general formula , where M is a metal and ''n'' is 1, 2,...; ''carboxylate ...

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 a ...

-based

pharmaceuticals A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and rel ...

, for example ones based on betamethasone or hydrocortisone, include the steroid as the valerate ester.

Examples

Methyl valerate Methyl pentanoate, commonly known as methyl valerate, is the methyl ester of pentanoic acid (valeric acid) with a fruity odor. Methyl pentanoate is commonly used in fragrances, beauty care, soap, laundry detergents at levels of 0.1–1%. In a ...

* 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 *

Testosterone valerate Testosterone valerate, or testosterone pentanoate, also known as androst-4-en-17β-ol-3-one 17β-valerate, is a synthetic, steroidal androgen and an androgen ester – specifically, the C17β valerate ester of testosterone – which is used in ...

References

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