Editing Valeric acid

{{Short description|Carboxylic acid – CH3(CH2)3COOH}}
{{Distinguish|Valerenic acid}}
{{chembox
| Reference=<ref>''[[Merck Index]]'', 13th Edition, 2001, page 1764.</ref>
| Name = Valeric acid
| ImageFile = Valeric_acid_acsv.svg
| ImageClass = skin-invert-image
| ImageSize = 150px 
| ImageName = Valeric acid
| ImageFile2 = Valeric-acid-3D-balls.png
| ImageSize2 = 180px 
| IUPACName = Pentanoic acid
| OtherNames = 1-Butanecarboxylic acid<br />Propylacetic acid<br />C5:0 ([[Lipid number]]s)
|Section1={{Chembox Identifiers
| index_label    = Valeric acid
| index1_label   = Valerate
| IUPHAR_ligand = 1061
| SMILES = CCCCC(O)=O
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 109-52-4
| CASNo1 = 10023-74-2
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = GZK92PJM7B
| ChEBI = 17418
| ChEBI1 = 31011
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 268736
| EINECS = 203-677-2
| PubChem = 7991
| PubChem1 = 114781
| RTECS = YV6100000
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 7701
| ChemSpiderID1 = 102757
| InChI = 1/C5H10O2/c1-2-3-4-5(6)7/h2-4H2,1H3,(H,6,7)
| InChIKey = NQPDZGIKBAWPEJ-UHFFFAOYAU
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C5H10O2/c1-2-3-4-5(6)7/h2-4H2,1H3,(H,6,7)
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = NQPDZGIKBAWPEJ-UHFFFAOYSA-N
  }}
|Section2={{Chembox Properties
| C=5 | H=10 | O=2
| Appearance = Colorless liquid
| Density = 0.930 g/cm<sup>3</sup>
| Solubility = 4.97 g/100 mL
| MeltingPtC = −34.5
| BoilingPtC = 185
| pKa = 4.82
| Viscosity = 
| MagSus = −66.85·10<sup>−6</sup> cm<sup>3</sup>/mol
  }}
|Section7={{Chembox Hazards
| Hazards_ref =<ref name="sigma">{{cite web |url=https://www.sigmaaldrich.com/catalog/product/aldrich/W310107?lang=en&region=GB |author=Sigma-Aldrich |title=Valeric acid |access-date=2020-09-29 }}</ref>
| GHSPictograms = {{GHS05}}
| GHSSignalWord = Danger
| ExternalSDS =
| NFPA-H = 3 | NFPA-F = 1 | NFPA-R = 0
| FlashPtC = 86
| HPhrases = {{H-phrases|314|412}}
| PPhrases = {{P-phrases|273|280|303+361+353|305+351+338+310}}
  }}
|Section8={{Chembox Related
| OtherCompounds = [[Butyric acid]], [[Hexanoic acid]]
  }}
}}

'''Valeric acid''' or  '''pentanoic acid''' is a straight-chain [[alkyl]] [[carboxylic acid]] with the [[chemical formula]] {{chem2|CH3(CH2)3COOH}}. Like other low-molecular-weight carboxylic acids, it has an [[unpleasant odor]].  It is found in the perennial flowering plant ''[[Valeriana officinalis]]'', from which it gets its name. Its primary use is in the synthesis of its [[ester]]s. [[Carboxylate salt|Salt]]s and [[ester]]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 (herb)|valerian]] (''Valeriana officinalis''), from which it gets its name.<ref name=EB1911>{{cite EB1911 |wstitle=Valeric Acid |volume=27 |page=859}}</ref> The dried root of this plant has been used medicinally since antiquity.<ref>{{cite journal |doi=10.2478/v10136-009-0002-z |doi-access=free |title=Biomedically relevant chemical constituents of ''Valeriana officinalis'' |year=2010 |last1=Patočka |first1=Jiří |last2=Jakl |first2=Jiří |journal=Journal of Applied Biomedicine |volume=8 |pages=11–18 }}</ref> The related [[3-Methylbutanoic acid|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 alcohol]]s.<ref>{{cite journal |doi=10.1039/JS8682100074 |title=On the isomeric forms of valeric acid |year=1868 |last1=Pedler |first1=Alexander |journal=Journal of the Chemical Society |volume=21 |pages=74–76 |url=https://zenodo.org/record/2175638 }}</ref>
Valeric acid is one volatile component in swine manure.  Other components include other carboxylic acids, [[skatole]], [[trimethyl amine]], and [[isovaleric acid]].<ref>{{cite journal|doi=10.1016/j.chemosphere.2012.04.061|pmid=22682363|title=Volatile organic compounds at swine facilities: A critical review|journal=Chemosphere|volume=89|issue=7|pages=769–788|year=2012|last1=Ni|first1=Ji-Qin|last2=Robarge|first2=Wayne P.|last3=Xiao|first3=Changhe|last4=Heber|first4=Albert J.|bibcode=2012Chmsp..89..769N}}</ref> It is also a flavor component in some foods.<ref>{{cite journal |doi=10.1080/00021369.1970.10859653 |title=Studies on Flavor Components of Roasted Barley |year=1970 |last1=Wang |first1=Pao-Shui |last2=Kato |first2=Hiromichi |last3=Fujimaki |first3=Masao |journal=Agricultural and Biological Chemistry |volume=34 |issue=4 |pages=561–567 }}</ref>

==Manufacture==
In industry, valeric acid is produced by the [[oxo process]] from [[1-butene]] and [[syngas]], forming [[valeraldehyde]], which is [[oxidised]] to the final product.<ref name=Ullmann/>

: {{chem2|H2 + CO + CH3CH2CH\dCH2 → 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]].<ref>{{cite journal |doi=10.1002/anie.201000655 |title=Valeric Biofuels: A Platform of Cellulosic Transportation Fuels |year=2010 |last1=Lange |first1=Jean-Paul |last2=Price |first2=Richard |last3=Ayoub |first3=Paul M. |last4=Louis |first4=Jurgen |last5=Petrus |first5=Leo |last6=Clarke |first6=Lionel |last7=Gosselink |first7=Hans |journal=Angewandte Chemie International Edition |volume=49 |issue=26 |pages=4479–4483 |pmid=20446282 |doi-access=free }}</ref><ref>{{cite journal|doi=10.1039/C7GC02503C|title=Conversion of levulinic acid and alkyl levulinates into biofuels and high-value chemicals|journal=Green Chemistry|volume=19|issue=23|pages=5527–5547|year=2017|last1=Yan|first1=Long|last2=Yao|first2=Qian|last3=Fu|first3=Yao}}</ref>

==Reactions==
Valeric acid reacts as a typical carboxylic acid: it can form [[amide]], [[ester]], [[acid anhydride|anhydride]], and [[acyl chloride|chloride]] derivatives.<ref>{{cite book |doi=10.1039/9781847556196-00096  |chapter=Carboxylic acids and derivatives |title=General and Synthetic Methods |year=1985 |last1=Jenkins |first1=P. R. |volume=7 |pages=96–160 |isbn=978-0-85186-884-4 }}</ref> 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.<ref>{{cite journal |doi=10.1080/10408398609527435 |title=Meat flavor volatiles: A review of the composition, techniques of analysis, and sensory evaluation |year=1986 |last1=Shahidi |first1=Fereidoon |last2=Rubin |first2=Leon J. |last3=d'Souza |first3=Lorraine A. |last4=Teranishi |first4=Roy |last5=Buttery |first5=Ron G. |journal=CRC Critical Reviews in Food Science and Nutrition |volume=24 |issue=2 |pages=141–243 |pmid=3527563 }}</ref> 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.<ref>{{cite web |url=http://www.inchem.org/documents/jecfa/jecmono/v040je10.htm |title=Safety evaluation of certain food additives and contaminants |author=FAO/WHO Expert Committee on food additives |date=1998 |access-date=2020-09-30}}</ref> 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.<ref name=Ullmann>{{Ullmann|first1=Wilhelm|last1=Riemenschneider|title=Carboxylic Acids, Aliphatic|year=2002|doi=10.1002/14356007.a05_235}}</ref> Typical examples are the [[methyl valerate]]s,<ref>{{cite web |url=http://www.thegoodscentscompany.com/data/rw1008901.html |title=Methyl valerate |website=The Good Scents Company |access-date=2020-09-30 }}</ref> [[ethyl valerate]]s,<ref>{{cite web |url=http://www.thegoodscentscompany.com/data/rw1000701.html |title=Ethyl valerate |website=The Good Scents Company |access-date=2020-09-30 }}</ref> and [[pentyl valerate]]s.<ref>{{cite web |url=http://www.thegoodscentscompany.com/data/rw1005951.html |title=Amyl valerate |website=The Good Scents Company |access-date=2020-09-30 }}</ref>

==Biology==
In humans, valeric acid is a minor product<ref>{{cite journal |doi=10.3390/nu12041107  |title=The Effect of Probiotics on the Production of Short-Chain Fatty Acids by Human Intestinal Microbiome |year=2020 |last1=Markowiak-Kopeć |first1=Paulina |last2=Śliżewska |first2=Katarzyna |journal=Nutrients |volume=12 |issue=4 |page=1107 |pmid=32316181 |pmc=7230973 |s2cid=216075062 |doi-access=free }}</ref> of the [[gut microbiome]] and can also be produced by metabolism of its esters found in food.<ref>{{cite web |url=https://hmdb.ca/metabolites/HMDB0000892 |title=Metabocard for Valeric acid |website= Human Metabolome Database |access-date=2020-09-30 |date=2020-04-23 }}</ref> The restoration of levels of this acid in the gut has been suggested as the mechanism that results in control of [[Clostridioides difficile infection|''Clostridioides difficile'' infection]] after [[fecal microbiota transplant]].<ref>{{cite journal |doi=10.1053/j.gastro.2018.07.014 |title=Inhibiting Growth of Clostridioides difficile by Restoring Valerate, Produced by the Intestinal Microbiota |year=2018 |last1=McDonald |first1=Julie A.K. |last2=Mullish |first2=Benjamin H. |last3=Pechlivanis |first3=Alexandros |last4=Liu |first4=Zhigang |last5=Brignardello |first5=Jerusa |last6=Kao |first6=Dina |last7=Holmes |first7=Elaine |last8=Li |first8=Jia V. |last9=Clarke |first9=Thomas B. |last10=Thursz |first10=Mark R. |last11=Marchesi |first11=Julian R. |journal=Gastroenterology |volume=155 |issue=5 |pages=1495–1507.e15 |pmid=30025704 |pmc=6347096 }}
</ref>

==Valerate salts and esters==
The '''valerate''', or '''pentanoate''',  [[ion]] is {{chem2|C4H9COO-|auto=yes}}, 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]]-based [[pharmaceuticals]], for example ones based on [[betamethasone]] or [[hydrocortisone]], include the steroid as the valerate ester.

===Examples===
*[[Estradiol valerate]]
*[[Testosterone valerate]]
*[[Methyl pentanoate|Methyl valerate]]
*[[Ethyl pentanoate|Ethyl valerate]]
*[[pentyl pentanoate|Pentyl valerate]]
*[[Betamethasone valerate]]
*[[Hydrocortisone valerate]]

== See also ==
{{wiktionary}}
* [[List of saturated fatty acids]]
* [[List of carboxylic acids]]
* [[4-Hydroxy-4-methylpentanoic acid]]
* [[Pivalic acid]] (2,2-dimethylpropanoic acid)
* [[3-Methylbutanoic acid]], also called isovaleric acid
* [[Valproic acid]]

== References ==
{{Reflist}}

{{Fatty acids}}
{{Chocolate}}

{{Authority control}}

[[Category:GABA analogues]]
[[Category:Fatty acids]]
[[Category:Alkanoic acids]]
[[Category:Foul-smelling chemicals]]