Hiragonic acid

Hiragonic acid
Names
	IUPAC name (6E,10E,14E)hexadeca-6,10,14-trienoic acid
	Other names C16:3n-2,6,10
Identifiers
CAS Number	4444-12-6 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:180366;
ChemSpider	4445939;
PubChem CID	5282812;
CompTox Dashboard (EPA)	DTXSID40712155 ;
	InChI InChI=1S/C16H26O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16(17)18/h2-3,6-7,10-11H,4-5,8-9,12-15H2,1H3,(H,17,18)/b3-2+,7-6+,11-10+ Key: ZKCRKOCVERWCLP-DJWHJZFYSA-N;
	SMILES CC=CCCC=CCCC=CCCCCC(=O)O;
Properties
Chemical formula	C16H26O2
Molar mass	250.382 g·mol−1
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Hiragonic acid is a linear fatty acid with 16 carbon atoms and three double bonds in the trans-configuration.^[1]^[2] The compound is also a polyunsaturated carboxylic acid; its molecular formula is C₁₆H₂₆O₂.

Discovery and natural occurrence

The acid was identified in 1929 by Japanese researchers Yoshiyuki Toyama and Tomotaro Tsuchyia^[3] in the oil of Japanese sardine (Clupanodon melanostica).^[4] In 1935, its structure was clarified by the same researchers^[5] who also proposed the current name—derived from the Japanese word for sardine: hirago.^[6] The acid was subsequently isolated in the oil of bonito and in the red alga Hypnea musciformis.^[7]

Some studies have identified hiragonic acid in Pongamia pinnata seed oil.^[8]

Properties

At room temperature between 4 °C and 20 °C, the acid forms a yellow liquid with a density of 0.9288 g/cm³ and a refractive index of 1.4855 at 20 °C. The compound is soluble in acetone, ethanol, diethyl ether, and methanol.^[9]

There are doubts about the all-trans configuration of hiragonic acid. Some authors attribute the name "hiragonic acid" to other positional or cis-isomers of hexadecatrienoic acid.^[10]^[11]

References

^ Eastwood, Martin (5 June 2013). Principles of Human Nutrition. John Wiley & Sons. ISBN 978-1-118-76053-6. Retrieved 4 June 2025.
^ "Trivial names of fatty acids-Part 1 – AOCS". aocs.org. Retrieved 4 June 2025.
^ Borgstrom, Georg (2 December 2012). Fish As Food V1: Production, Biochemistry,and Microbiology. Elsevier. ISBN 978-0-323-14280-9. Retrieved 4 June 2025.
^ Toyama, Yoshiyuki; Tsuchiya, Totnotaro (1 April 1929). "UEBER DIE HOCHUNGESÄTTIGTEN SÄUREN DES SARDINENÖLS. I. MITTEILUNG: EINE NEUE SÄURE C16H26O2 AND DIE HOCHUNGESÄTTIGTEN C18— SÄUREN". Bulletin of the Chemical Society of Japan. 4 (4): 83–91. doi:10.1246/bcsj.4.83. ISSN 0009-2673. Retrieved 4 June 2025.
^ Toyama, Yoshiyuki; Tsuchiya, Tomotaro (1 May 1935). "The Highly Unsaturated Acids in Sardine Oil. Ii. The Constitution of Hiragonic Acid C16H26O2". Bulletin of the Chemical Society of Japan. 10 (5): 192–199. doi:10.1246/bcsj.10.192. ISSN 0009-2673. Retrieved 4 June 2025.
^ The Etymology of Chemical Names: Tradition and Convenience vs. Rationality in Chemical Nomenclature. Walter de Gruyter GmbH & Co KG. 8 October 2019. ISBN 978-3-11-061124-3. Retrieved 4 June 2025.
^ Blunt, John W.; Munro, Murray H. G. (19 September 2007). Dictionary of Marine Natural Products. CRC Press. p. H-258. ISBN 978-1-040-22179-2. Retrieved 4 June 2025.
^ Shameel, S.; Usmanghani, K.; Ali, M. S.; Ahmad, V. U. (January 1996). "Chemical constituents from the seeds of Pongamia pinnata (L.) Pierre". Pakistan Journal of Pharmaceutical Sciences. 9 (1): 11–20. ISSN 1011-601X. PMID 16414771.
^ Ralston, A. W. (1948). Fatty Acids and Their Derivatives. New York: John Wiley and Sons. Retrieved 5 June 2025.
^ "Trivial names of fatty acids-Part 1 – AOCS". aocs.org. Retrieved 9 June 2025.
^ "LIPID MAPS". lipidmaps.org. Retrieved 9 June 2025.

[1] Eastwood, Martin (5 June 2013). Principles of Human Nutrition. John Wiley & Sons. ISBN 978-1-118-76053-6. Retrieved 4 June 2025.

[2] "Trivial names of fatty acids-Part 1 – AOCS". aocs.org. Retrieved 4 June 2025.

[3] Borgstrom, Georg (2 December 2012). Fish As Food V1: Production, Biochemistry,and Microbiology. Elsevier. ISBN 978-0-323-14280-9. Retrieved 4 June 2025.

[4] Toyama, Yoshiyuki; Tsuchiya, Totnotaro (1 April 1929). "UEBER DIE HOCHUNGESÄTTIGTEN SÄUREN DES SARDINENÖLS. I. MITTEILUNG: EINE NEUE SÄURE C16H26O2 AND DIE HOCHUNGESÄTTIGTEN C18— SÄUREN". Bulletin of the Chemical Society of Japan. 4 (4): 83–91. doi:10.1246/bcsj.4.83. ISSN 0009-2673. Retrieved 4 June 2025.

[5] Toyama, Yoshiyuki; Tsuchiya, Tomotaro (1 May 1935). "The Highly Unsaturated Acids in Sardine Oil. Ii. The Constitution of Hiragonic Acid C16H26O2". Bulletin of the Chemical Society of Japan. 10 (5): 192–199. doi:10.1246/bcsj.10.192. ISSN 0009-2673. Retrieved 4 June 2025.

[6] The Etymology of Chemical Names: Tradition and Convenience vs. Rationality in Chemical Nomenclature. Walter de Gruyter GmbH & Co KG. 8 October 2019. ISBN 978-3-11-061124-3. Retrieved 4 June 2025.

[7] Blunt, John W.; Munro, Murray H. G. (19 September 2007). Dictionary of Marine Natural Products. CRC Press. p. H-258. ISBN 978-1-040-22179-2. Retrieved 4 June 2025.

[8] Shameel, S.; Usmanghani, K.; Ali, M. S.; Ahmad, V. U. (January 1996). "Chemical constituents from the seeds of Pongamia pinnata (L.) Pierre". Pakistan Journal of Pharmaceutical Sciences. 9 (1): 11–20. ISSN 1011-601X. PMID 16414771.

[9] Ralston, A. W. (1948). Fatty Acids and Their Derivatives. New York: John Wiley and Sons. Retrieved 5 June 2025.

[10] "Trivial names of fatty acids-Part 1 – AOCS". aocs.org. Retrieved 9 June 2025.

[11] "LIPID MAPS". lipidmaps.org. Retrieved 9 June 2025.

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