Arachidic acid
Preferred IUPAC name
Icosanoic acid
Other names
Eicosanoic acid
n-Eicosanoic acid
Arachidic acid
Arachic acid
C20:0 (Lipid numbers)
3D model (JSmol)
ECHA InfoCard 100.007.302 Edit this at Wikidata
  • InChI=1S/C20H40O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20(21)22/h2-19H2,1H3,(H,21,22) checkY
  • InChI=1/C20H40O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20(21)22/h2-19H2,1H3,(H,21,22)
Molar mass 312.538 g·mol−1
Appearance White crystalline solid
Density 0.8240 g/cm3
Melting point 75.4 °C (167.7 °F; 348.5 K)
Boiling point 328 °C (622 °F; 601 K)
Practically insoluble in water
Flash point 110 °C (230 °F; 383 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Arachidic acid, also known as icosanoic acid, is a saturated fatty acid with a 20-carbon chain. It is a minor constituent of cupuaçu butter (7%),[2] perilla oil (0–1%),[3] peanut oil (1.1–1.7%),[4] corn oil (3%),[5] and cocoa butter (1%).[6] The salts and esters of arachidic acid are known as arachidates.

Its name derives from the Latin arachis—peanut. It can be formed by the hydrogenation of arachidonic acid.

Reduction of arachidic acid yields arachidyl alcohol.

Arachidic acid is used for the production of detergents, photographic materials and lubricants.


  1. ^ *Merck Index, 11th Edition, 791
  2. ^ Cohen, K. de O. & Jackix, M. de N. H. (2009). "Características químicas e física da gordura de cupuaçu e da manteiga de cacau" (PDF). Document / Embrapa Cerrados (in Portuguese) (269): 1–22.
  3. ^ Shin, Hyo-Sun (1997). "9. Lipid Composition and Nutritional and Physiological Roles of Perilla Seed and its Oil". In Yu, He-Ci; Kosuna, Kenichi; Haga, Megumi (eds.). Perilla: The Genus Perilla. London: CRC Press. p. 93. doi:10.1201/9781439822715. ISBN 9789057021718. Perilla seed contains about 38-45% of lipid (Sonntag, 1979; Vaughan, 1970).[permanent dead link]
  4. ^ Beare-Rogers, J.; Dieffenbacher, A.; Holm, J.V. (2001). "Lexicon of lipid nutrition (IUPAC Technical Report)". Pure and Applied Chemistry. 73 (4): 685–744. doi:10.1351/pac200173040685. S2CID 84492006.
  5. ^ U.S. Department of Agriculture, Agricultural Research Service. 2007. USDA National Nutrient Database for Standard Reference, Release 20. Nutrient Data Laboratory Home Page
  6. ^ USDA nutrient database Archived March 3, 2015, at the Wayback Machine