Ximenynic acid (C18:1, n-9) is an unsaturated fatty acid with one double bond, found on the 9th carbon of the fatty acid chain. It’s pretty unique to Ximenia seed oil – hence the common name of ximenynic acid.
The proper name is trans-11-octadecen-9-ynoic acid (C18H30O2), the trans part indicating that the atoms on either side of the double bond are diagonally arranged, so it doesn’t have a kink in the middle, like oleic acid would, so the fatty acid molecules can bunch together better, so they’re more solid at room temperature and will have higher viscosity.
The molecular weight is 278.4 grams per mole, and it has a melting point above room temperature, so its viscosity is higher than oleic acid, which is also C18:1.
It may have some anti-aging properties and may help with cellulite.