Ketoisanic acid is a linear fatty acid composed of 18 carbon atoms, with two triple bonds in the positions 9â¡10 and 11â¡12, a double bond in the position 17=18, and a ketone substituent in the position 8. This is one of the rare polyacetylenic acids with conjugated triple bonds, the oxygenated isanic acid.
The acid can be detected, at concentrations of 1âÂÂ3%, together with isanic and isanolic acid, in the seed oil of the tree Ongokea gore or Ongokea klaineana; both are plants from equatorial Africa, called "isano" in the local language.