Palmitic acid

Palmitic acid(hexadecanoic acidinIUPAC nomenclature) is afatty acidwith a 16-carbon chain. It is the most commonsaturated fatty acidfound in animals, plants and microorganisms.Itschemical formulaisCH3(CH2)14COOH, and its C:D ratio (the total number of carbon atoms to the number of carbon-carbon double bonds) is 16:0. It is a major component ofpalm oilfrom the fruit ofElaeis guineensis(oil palms), making up to 44% of total fats. Meats, cheeses, butter, and other dairy products also contain palmitic acid, amounting to 50–60% of total fats.
Palmitatesare thesaltsandestersof palmitic acid. The palmitate anion is the observed form of palmitic acid at physiologic pH (7.4). Major sources of C16:0 are palm oil, palm kernel oil, coconut oil, and milk fat.
Palmitic acid was discovered byEdmond Frémy(in 1840) in thesaponificationof palm oil, which process remains today the primary industrial route for producing the acid.Triglycerides(fats) inpalm oilarehydrolysedby high-temperature water and the resulting mixture isfractionally distilled.
Palmitic acid is produced by a wide range of plants and organisms, typically at low levels. Among common foods it is present inmilk,butter,cheese, and somemeats, as well ascocoa butter,olive oil,soybean oil, andsunflower oil, (see table).Karukascontain 44.90% palmitic acid.Thecetylester of palmitic acid,cetyl palmitate, occurs inspermaceti.
Palmitic acid is the first fatty acid produced duringfatty acid synthesisand is the precursor to longer fatty acids. As a consequence, palmitic acid is a major body component of animals. In humans, one analysis found it to make up 21–30% (molar) of humandepot fat,and it is a major, but highly variable, lipid component ofhuman breast milk.Palmitate negatively feeds back onacetyl-CoA carboxylase(ACC), which is responsible for convertingacetyl-CoAtomalonyl-CoA, which in turn is used to add to the growingacyl chain, thus preventing further palmitate generation.
Some proteins are modified by the addition of a palmitoyl group in a process known aspalmitoylation. Palmitoylation is important for localisation of manymembrane proteins.
Palmitic acid is used to producesoaps,cosmetics, and industrial moldrelease agents. These applications usesodium palmitate, which is commonly obtained bysaponificationof palm oil.  To this end, palm oil, rendered from palm trees (speciesElaeis guineensis), is treated withsodium hydroxide(in the form of caustic soda or lye), which causeshydrolysisof theestergroups, yieldingglyceroland sodium palmitate.
Because it is inexpensive and adds texture and "mouthfeel" to processed foods (convenience food), palmitic acid and its sodium salt find wide use in foodstuffs. Sodium palmitate is permitted as a natural additive inorganicproducts.
Aluminiumsaltsof palmitic acid andnaphthenic acidwere thegelling agentsused with volatile petrochemicals duringWorld War IIto producenapalm. The word "napalm" is derived from the words naphthenic acid and palmitic acid.
It is well accepted in the medical community that palmitic acid from dietary sources raiseslow-density lipoprotein(LDL) and total cholesterol.TheWorld Health Organizationhave stated there is convincing evidence that palmitic acid increasescardiovascular diseaserisk.
A 2021 review indicated that replacing dietary palmitic acid and other saturated fatty acids withunsaturated fatty acids, such asoleic acid, could reduce severalbiomarkersof cardiovascular andmetabolicdiseases.