MOLECULE

Margaric acid

Heptadecanoic acid, also known as margaric acid, belongs to the class of organic compounds known as long-chain fatty acids. These are fatty acids with an aliphatic tail that contains between 13 and 21 carbon atoms. Heptadecanoic acid is a very hydrophobic molecule, practically insoluble in water, and relatively neutral. Heptadecanoic acid is a constituent of Erythrina crista-galli trunkwood and bark. Heptadecanoic acid is a fatty acid of exogenous (primarily ruminant) origin. Many "odd" lengths long chain amino acids are derived from the consumption of dairy fats (milk and meat). Heptadecanoic acid is usually found in trace amounts and constitutes 0.61% of milk fat and 0.83% of ruminant meat fat. The content of heptadecanoic acid in the subcutaneous adipose tissue of humans appears to be a good biological marker of long-term milk fat intake in free-living individuals in populations with high consumption of dairy products (PMID: 9701185). It is a common constituent of lipids, such as those present in Physalia physalis (Portuguese-man-of-war). Heptadecanoic acid is a constituent of marijuana smoke (https://doi.org/10.1007/978-1-59259-947-9_2). Heptadecanoic acid has pheromonic and allomonic properties for insects and reptiles. The subcaudal gland secretions of the European badger (Meles meles) and the occipital gland secretions of male bactrian camels (Camelus bactrianus) contain many pheromonic chemicals, including heptadecanoic acid, that aid in finding and selection of mates (PMID: 24414593). Heptadecanoic acid is an attractant of the khapra beetle (Trogoderma granarium) and the yellow fever mosquito (Aedes aegypti) but as a repellent of the common house mosquito (Culex pipiens; doi: 10.5962/bhl.title.49749). Heptadecanoic acid is also found in the precloacal gland secretions of many reptiles belonging to the order squamata, including the common leopard gecko (Eublepharis macularius; PMID 24264893) and the European viper (Vipera berus), where it is used for the identification of sexual partners (doi:10.1007/bf00579807).