Heneicosane
{{chembox
| ImageFile = Heneicosane.svg
| ImageFile_Ref = {{chemboximage|correct|??}}
| ImageSize = 275
| ImageAlt = Structural formula of heneicosane
| ImageAlt1 =
| PIN = Henicosane
| OtherNames = n-Heneicosane
|Section1={{Chembox Identifiers
| CASNo = 629-94-7
| CASNo_Ref = {{cascite|correct|CAS}}
| PubChem = 12403
| ChemSpiderID = 11897
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| UNII = I93S5U5DMP
| UNII_Ref = {{fdacite|correct|FDA}}
| EINECS = 211-118-9
| DrugBank =
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| KEGG =
| KEGG_Ref = {{keggcite|correct|kegg}}
| MeSHName =
| ChEBI = 32931
| ChEBI_Ref = {{ebicite|correct|EBI}}
| Beilstein = 1748500
| SMILES = CCCCCCCCCCCCCCCCCCCCC
| StdInChI = 1S/C21H44/c1-3-5-7-9-11-13-15-17-19-21-20-18-16-14-12-10-8-6-4-2/h3-21H2,1-2H3
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = FNAZRRHPUDJQCJ-UHFFFAOYSA-N
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
}}
|Section2={{Chembox Properties
| C=21 | H=44
| Appearance = Waxy solid
| Odor =
| Density = 0.7919 g mL−1
| MeltingPtC = 40.5
| BoilingPtK = 629.25
| Solubility = 2.9·10−11 g/L
| LogP = 10.65
| VaporPressure = 8.73·10−5 mm Hg
| HenryConstant = 120 atm·m3/mole
| RefractIndex = 1.4441
}}
|Section3={{Chembox Thermochemistry
| DeltaHf =
| DeltaHc =
| Entropy =
| HeatCapacity =
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|Section4={{Chembox Hazards
| NFPA-H =1
| NFPA-F =1
| NFPA-R =0
| FlashPtC = 113
}}
|Section5={{Chembox Related
| OtherFunction_label = alkanes
| OtherFunction = {{unbulleted list|Icosane|Tetracosane}}
}}
}}
Heneicosane is the organic compound with the formula CH3(CH2)19CH3. It is the straight chain, saturated C21 hydrocarbon. It is a white wax.
Natural occurrence
Heneicosane is used as a pheromone by the queen or king termites in the species Reticulitermes flavipes.{{cite web|title=Termite queen, king recognition pheromone identified|url=https://phys.org/news/2018-03-termite-queen-king-recognition-pheromone.html|access-date=21 March 2018|date=19 March 2018}} It also attracts mosquitoes in the genus Aedes and can be used in mosquito baits.{{cite journal|last1=Kumar|first1=P|last2=Lomash|first2=V|last3=Jatav|first3=PC|last4=Kumar|first4=A|last5=Pant|first5=SC|title=Prenatal developmental toxicity study of n-heneicosane in Wistar rats.|journal=Toxicology and Industrial Health|date=January 2016|volume=32|issue=1|pages=118–25|doi=10.1177/0748233713498438|pmid=24060842|bibcode=2016ToxIH..32..118K|s2cid=206543815}} This works in nature as the hydrocarbon is produced in the skin of the larva. A 1:100000 fraction in water is the most attractive, but if the concentration is 1:1000 then mosquitoes are repelled instead.{{cite journal|last1=Seenivasagan|first1=T|last2=Sharma|first2=KR|last3=Sekhar|first3=K|last4=Ganesan|first4=K|last5=Prakash|first5=S|last6=Vijayaraghavan|first6=R|title=Electroantennogram, flight orientation, and oviposition responses of Aedes aegypti to the oviposition pheromone n-heneicosane.|journal=Parasitology Research|date=March 2009|volume=104|issue=4|pages=827–33|doi=10.1007/s00436-008-1263-2|pmid=19018567|s2cid=6880282}} Heneicosane is one of the major components of the safflower flower essential oil (Carthamus tinctorius).{{cite journal|last1=Asgarpanah|first1=J|last2=Kazemivash|first2=N|title=Phytochemistry, pharmacology and medicinal properties of Carthamus tinctorius L.|journal=Chinese Journal of Integrative Medicine|date=February 2013|volume=19|issue=2|pages=153–9|doi=10.1007/s11655-013-1354-5|pmid=23371463|s2cid=386921}} All parts of the plant Periploca laevigata contain heneicosane.{{cite journal|last1=Zito|first1=P|last2=Sajeva|first2=M|last3=Bruno|first3=M|last4=Rosselli|first4=S|last5=Maggio|first5=A|last6=Senatore|first6=F|title=Essential oils composition of Periploca laevigata Aiton subsp. angustifolia (Labill.) Markgraf (Apocynaceae-Periplocoideae).|journal=Natural Product Research|date=2013|volume=27|issue=3|pages=255–65|doi=10.1080/14786419.2012.671319|pmid=22439883|s2cid=205838364}} Rosa damascena flower essential oil contains 5% heneicosane.{{cite journal|last1=Sadraei|first1=H|last2=Asghari|first2=G|last3=Emami|first3=S|title=Inhibitory effect of Rosa damascena Mill flower essential oil, geraniol and citronellol on rat ileum contraction.|journal=Research in Pharmaceutical Sciences|date=January 2013|volume=8|issue=1|pages=17–23|pmid=24459472|pmc=3895296}} Sambucus nigra contains 2.3%.