:Citral
{{Use dmy dates|date=March 2021}}
{{dist|Geraniol}}
{{chembox
| Watchedfields = changed
| verifiedrevid = 443528330
| Reference = Citral, The Merck Index, 12th Edition.
| Name = Citral
| ImageFile = Geranial 2.svg
| ImageAlt = Skeletal formula of geranial
| ImageCaption = Geranial
| ImageFile1 = Geranial 3D ball.png
| ImageAlt1 = Ball-and-stick model of the geranial molecule
| ImageFile2 = Neral_svg.svg
| ImageAlt2 = Skeletal formula of neral
| ImageCaption2 = Neral
| ImageFile3 = Neral-3D-balls.png
| ImageAlt3 = Ball-and-stick model of the neral molecule
| IUPACName = 3,7-dimethylocta-2,6-dienal
| OtherNames = citral
geranialdehyde
|Section1={{Chembox Identifiers
| IUPHAR_ligand = 6327
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 16980
| SMILES = O=CC=C(C)CCC=C(C)C
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 553578
| PubChem = 638011
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = T7EU0O9VPP
| InChI = 1/C10H16O/c1-9(2)5-4-6-10(3)7-8-11/h5,7-8H,4,6H2,1-3H3/b10-7+
| InChIKey = WTEVQBCEXWBHNA-JXMROGBWBB
| SMILES1 = O=C/C=C(/CC/C=C(/C)C)C
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 1080997
| 3DMet = B00306
| EC_number = 226-394-6
| UNNumber = 2810
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C10H16O/c1-9(2)5-4-6-10(3)7-8-11/h5,7-8H,4,6H2,1-3H3/b10-7+
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = WTEVQBCEXWBHNA-JXMROGBWSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 5392-40-5
| RTECS = RG5075000
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C01499
}}
|Section2={{Chembox Properties
| Formula = C10H16O
| MolarMass = 152.24 g/mol
| Appearance = Pale yellow liquid
| Odor = Lemon like
| Density = 0.893 g/cm3
| VaporPressure = 0.22{{nbsp}}mmHg (20{{nbsp}}°C)
| Solubility =
| MeltingPt =
| BoilingPtC = 229
| pKa =
| MagSus = {{val|−98.9e−6|u=cm3/mol}}
}}
|Section3={{Chembox Structure
| Dipole =
}}
|Section7={{Chembox Hazards
| NFPA-H = 0 | NFPA-F = 1 | NFPA-R = 0 | NFPA-S =
| GHSPictograms = {{GHS07}}
| GHSSignalWord = Warning
| HPhrases = {{H-phrases|315|317}}
| PPhrases = {{P-phrases|261|264|272|280|302+352|321|332+313|333+313|362|363|501}}
| FlashPtC = 91
}}
|Section8={{Chembox Related
| OtherFunction_label = alkenals
| OtherFunction = {{ubl
}}
| OtherCompounds =
}}
}}
Citral is an acyclic monoterpene aldehyde. Being a monoterpene, it is made of two isoprene units. Citral is a collective term which covers two geometric isomers that have their own separate names; the E-isomer is named geranial (trans-citral; α-citral{{cite journal |last1=Waghulde |first1=S. |last2=Parmar |first2=P. |last3=Mule |first3=J. |last4=Pashte |first4=D. |last5=Patil |first5=B. |last6=Modhale |first6=N. |last7=Gorde |first7=N. |last8=Kharche |first8=A. |last9=Kale |first9=M. |date=2020 |title=Lead Finding from Plant Cymbopogon Citratus with Immunomodulator Potentials through in Silico Methods |journal=Chemistry Proceedings |language=en |volume=3 |issue=1 |pages=77 |doi=10.3390/ecsoc-24-08302 |issn=2673-4583 |doi-access=free }}) or citral A. The Z-isomer is named neral (cis-citral; β-citral) or citral B. These stereoisomers occur as a mixture, often not in equal proportions; e.g. in essential oil of Australian ginger, the neral to geranial ratio is 0.61.{{cite book |last1=Zachariah |first1=T. J. |last2=Parthasarathy |first2=V. A. |last3=Chempakam |first3=B. |title=Chemistry of spices |page=76 |date=2008 |publisher=CABI |oclc=1120264204 |isbn=9781845934057 |location=Wallingford}}
Natural Occurrence
Citral is present in the volatile oils of several plants:{{cite book|last1=Fenaroli |first1=G. |last2=Furia |first2=T.E. |last3=Bellanca |first3=N. |title=Handbook of Flavor Ingredients |isbn=0-87819-532-7}}{{cite book|last1=Lawless |first1=J. |title=The Illustrated Encyclopedia of Essential Oils |date=2 November 1995 |publisher=Element |isbn=1-85230-661-0}}{{Cite web |url=http://www.aromaticplantproject.com/articles_archive/lemon_citrus_scented_oils.html |title=The Aromatic Plant Project |access-date=1 June 2008 |archive-date=24 November 2019 |archive-url=https://web.archive.org/web/20191124031814/http://www.aromaticplantproject.com/articles_archive/lemon_citrus_scented_oils.html |url-status=dead }}
{{bulleted list |
lemon myrtle (90–98%)|
Litsea citrata (90%)|
Litsea cubeba (70–85%)| lemongrass (65–85%)|
lemon tea-tree (70–80%)|
Ocimum gratissimum (66.5%)|
Lindera citriodora (about 65%)|
Calypranthes parriculata (about 62%)|
petitgrain (36%)|
lemon verbena (30–35%)|
lemon ironbark (26%)|
lemon balm (11%)|
lime (6–9%)|
lemon (2–5%)|
}}
Further, in the lipid fraction (essential oil) of Australian ginger (51–71%) Of the many sources of citral, the Australian myrtaceous tree, lemon myrtle, Backhousia citriodora F. Muell. (of the family Myrtaceae), is considered superior.{{cite journal |last1=Southwell |first1=Ian |title=Backhousia citriodora F. Muell. (Lemon Myrtle), an Unrivalled Source of Citral |journal=Foods |date=9 July 2021 |volume=10 |issue=7 |pages=1596 |doi=10.3390/foods10071596 |pmid=34359465 |pmc=8305781 |doi-access=free }}
Uses
=Fragrances=
Citral has a strong lemon (citrus) scent and is used as an aroma compound in perfumery. It is used to fortify lemon oil. (Nerol, another perfumery compound, has a less intense but sweeter lemon note.) The aldehydes citronellal and citral are considered key components responsible for the lemon note with citral preferred.
It also has pheromonal effects in acari and insects.{{cite journal |last1=Kuwahara |first1=Yasumasa |last2=Suzuki |first2=Hiroshi |last3=Matsumoto |first3=Katsuhiko |last4=Wada |first4=Yoshitake |title=Pheromone Study on Acarid Mites. XI. Function of Mite Body as Geometrical Isomerization and Reduction of Citral (the Alarm Pheromone) |journal=Applied Entomology and Zoology |date=1983 |volume=18 |issue=1 |pages=30–39 |doi=10.1303/aez.18.30 |doi-access=free }}{{cite journal |author1=Robacker, D.C. |author2=Hendry, L.B. |year=1977 |title=Neral and geranial: components of the sex pheromone of the parasitic wasp, Itoplectis conquisitor | journal=Journal of Chemical Ecology |volume=3 |pages=563–577 | doi = 10.1007/BF00989077 | issue = 5|s2cid=11568355 }}
The herb Cymbopogon citratus has shown promising insecticidal and antifungal activity against storage pests.{{cite journal |last1=Dubey |first1=N. K. |last2=Takeya |first2=Koichi |last3=Itokawa |first3=Hideji |title=Citral: A cytotoxic principle isolated from the essential oil of Cymbopogon citratus against P388 leukaemia cells |journal=Current Science |date=1997 |volume=73 |issue=1 |pages=22–24 |jstor=24098141 }}
= Food additive =
Citral is commonly used as a food additive ingredient.{{cite journal |last1=Liao |first1=Pei-Chun |last2=Yang |first2=Tsung-Shi |last3=Chou |first3=Ju-Ching |last4=Chen |first4=Jie |last5=Lee |first5=Shu-Ching |last6=Kuo |first6=Yueh-Hsiung |last7=Ho |first7=Chen-Lung |last8=Chao |first8=Louis Kuo-Ping |title=Anti-inflammatory activity of neral and geranial isolated from fruits of Litsea cubeba Lour |journal=Journal of Functional Foods |date=1 December 2015 |volume=19 |pages=248–258 |doi=10.1016/j.jff.2015.09.034 |doi-access=free }}
It has been tested (2016) in vitro against the food-borne pathogen Cronobacter sakazakii.{{cite journal |last1=Shi |first1=Chao |last2=Song |first2=Kaikuo |last3=Zhang |first3=Xiaorong |last4=Sun |first4=Yi |last5=Sui |first5=Yue |last6=Chen |first6=Yifei |last7=Jia |first7=Zhenyu |last8=Sun |first8=Huihui |last9=Sun |first9=Zheng |last10=Xia |first10=Xiaodong |title=Antimicrobial Activity and Possible Mechanism of Action of Citral against Cronobacter sakazakii |journal=PLOS ONE |date=14 July 2016 |volume=11 |issue=7 |pages=e0159006 |doi=10.1371/journal.pone.0159006 |pmid=27415761 |pmc=4945043 |bibcode=2016PLoSO..1159006S |doi-access=free }}
See also
References
{{reflist}}
External links
- [http://physchem.ox.ac.uk/MSDS/CI/citral.html MSDS] {{Webarchive|url=https://web.archive.org/web/20070818041949/http://physchem.ox.ac.uk/MSDS/CI/citral.html |date=18 August 2007 }}