Heptadecanoic acid


Heptadecanoic acid, or margaric acid, is a saturated fatty acid. Its molecular formula is CH315CO2H. Classified as an odd-chain fatty acid, it occurs as a trace component of the fat and milkfat of ruminants, but it does not occur in any natural animal or vegetable fat at high concentrations. For example, it comprises only 2.2% of the fats from the fruit of the durian species Durio graveolens. However, in the 19th and early 20th centuries, there were numerous reports of the acid being found in natural fats in significant amounts. Most likely, these were cases of misidentifying a eutectic mixture of palmitic and stearic acids. Salts and esters of heptadecanoic acid are called heptadecanoates.

Semiochemistry

For many species, heptadecanoic acid plays a part as a semiochemical - specifically it possesses pheromonic and allomonic properties. Heptadecanoic acid has been identified in the subcaudal gland secretions of the European badger and in the occipital gland secretions of male bactrian camels where it is one of the many pheromonic chemicals responsible for aiding in the finding and selection of mates.
Heptadecanoic acid is an attractant of the khapra beetle and the yellow fever mosquito but as a repellent of the common house mosquito.
Heptadecanoic acid is also found in the precloacal gland secretions of many reptiles belonging to the order squamata, including the common leopard gecko and the European viper, where it is used for the identification of sexual partners.