Gadoleic acid: structure, properties, and food sources

Gadoleic acid (20 carbon atoms) was discovered in cod liver oil by Bull H. in 1906 while the structure was clarified by Takano M. in 1933.
It is an unsaturated fatty acid (one cis (Z) double bond, from the methyl end is in omega-11 (ω-11) or n-11, so in shorthand 20:1n-11) fatty acid member of the sub-group called very long chain fatty acids (LCFA) (from 20 carbon atoms onwards).

Molecular weight: 310.51452 g/mol
Molecular formula: C20H38O2
IUPAC name: (Z)-icos-9-enoic acid
PubChem: 5282767

Gadoleic Acid
Fig. 1 – (Z)-icos-9-enoic Acid

In purified form, its melting point is at 23-23.5 °C (73.4-74.3 °F; 296.15-296.65 K) and boiling point at 170 °C (338 °F; 443.15 K) at 0.1 mmHg.

Other names
cis-gadoleic acid
9Z-eicosenoic acid
cis-9-icosenoic acid
cis-9-eicosenoic acid

Food sources of gadoleic acid

It occurs as glycerol ester in fish (where it originates from dietary crustacean) like cod, shark and ray or their liver oils, and vegetable oils like this from rapeseed.


  1. Akoh C.C. and Min D.B. “Food lipids: chemistry, nutrition, and biotechnology” 3th ed. 2008
  2. Chow Ching K. “Fatty acids in foods and their health implication” 3th ed. 2008

Biochemistry, metabolism and nutrition