Palmitic acid
Encyclopedia
Palmitic acid, or hexadecanoic acid in IUPAC nomenclature
, is one of the most common saturated fatty acid
s found in animals and plants. Its molecular formula is CH3(CH2)14CO2H. As its name indicates, it is a major component of the oil from palm trees (palm oil
, palm kernel
oil, and coconut oil
). Palmitate is a term for the salts and ester
s of palmitic acid. The palmitate anion is the observed form of palmitic acid at basic pH.
but also tallow
. The cetyl
ester of palmitic acid (cetyl palmitate) occurs in spermiceti. It was discovered by Edmond Frémy
in 1840, in saponified
palm oil.
Palmitic acid is prepared by treating fats and oils with water at a high pressure and temperature (above 200 °C), leading to the hydrolysis
of triglyceride
s. The resulting mixture is then distilled.
and from which longer fatty acids can be produced. Palmitate negatively feeds back on acetyl-CoA carboxylase
(ACC), which is responsible for converting acetyl-CoA to malonyl-CoA, which in turn is used to add to the growing acyl chain, thus preventing further palmitate generation. In biology, some proteins are modified by the addition of a palmitoyl group in a process known as palmitoylation
. Palmitoylation is important for membrane localisation of many proteins.
s. For these applications, the palmitic acid is neutralized with sodium hydroxide to give sodium palmitate. The most common route to sodium palmitate is saponification
, in which palm oil, rendered from the coconut palm nut, is treated with concentrated sodium hydroxide (in the form of caustic soda or lye), which causes hydrolysis
of the ester
groups. This procedure splits the ester groups in the oil into glycerol
and sodium palmitate.
Because it is inexpensive and benign, palmitic acid and its sodium salt find wide use including foodstuffs. Sodium palmitate is permitted as a natural additive in organic
products.
Hydrogenation
of palmitic acid yields cetyl alcohol
, which is used to produce detergents and cosmetics.
Recently, a long-acting antipsychotic medication, paliperidone
palmitate (marketed as INVEGA Sustenna), used in the treatment of schizophrenia
, has been synthesized using the oily palmitate ester as a long-acting release carrier medium when injected intramuscularly. The underlying method of drug delivery is similar to that used with decanoic acid
to deliver long-acting depot medication, in particular, neuroleptics such as haloperidol
decanoate.
were combined during World War II
to produce napalm concentrate (aluminum naphthenate and aluminum palmitate).
, evidence is "convincing" that consumption of palmitic acid increases risk of developing cardiovascular diseases, placing it in the same evidence category as trans fatty acids. The report does not cite any studies that actually found a link between palmitic acid intake and patient outcomes. Another study showed that palmitic acid has no hypercholesterolaemic effect if intake of linoleic acid
, an essential fatty acid, is greater than 4.5% of energy. On the other hand, it was shown that, if the diet contains trans fatty acids, the health effects are negative, causing an LDL cholesterol increase and HDL cholesterol decrease.
Retinyl palmitate
is an antioxidant
and a source of vitamin A
added to low fat milk to replace the vitamin content lost through the removal of milk fat. Palmitate is attached to the alcohol form of vitamin A, retinol
, to make vitamin A stable in milk.
IUPAC nomenclature
A chemical nomenclature is a set of rules to generate systematic names for chemical compounds. The nomenclature used most frequently worldwide is the one created and developed by the International Union of Pure and Applied Chemistry ....
, is one of the most common saturated fatty acid
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
s found in animals and plants. Its molecular formula is CH3(CH2)14CO2H. As its name indicates, it is a major component of the oil from palm trees (palm oil
Palm oil
Palm oil, coconut oil and palm kernel oil are edible plant oils derived from the fruits of palm trees. Palm oil is extracted from the pulp of the fruit of the oil palm Elaeis guineensis; palm kernel oil is derived from the kernel of the oil palm and coconut oil is derived from the kernel of the...
, palm kernel
Palm kernel
Many plants and trees like olive, soybean, canola, sunflower and coconut palm produce one type of oil. The fruits of the oil palm tree, however, yields two distinct oils - palm oil and palm kernel oil....
oil, and coconut oil
Coconut oil
Coconut oil is an edible oil extracted from the kernel or meat of matured coconuts harvested from the coconut palm . Throughout the tropical world, it has provided the primary source of fat in the diets of millions of people for generations. It has various applications in food, medicine, and industry...
). Palmitate is a term for the salts and ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
s of palmitic acid. The palmitate anion is the observed form of palmitic acid at basic pH.
Occurrence and production
Palmitic acid mainly occurs as its ester in triglycerides (fats), especially palm oilPalm oil
Palm oil, coconut oil and palm kernel oil are edible plant oils derived from the fruits of palm trees. Palm oil is extracted from the pulp of the fruit of the oil palm Elaeis guineensis; palm kernel oil is derived from the kernel of the oil palm and coconut oil is derived from the kernel of the...
but also tallow
Tallow
Tallow is a rendered form of beef or mutton fat, processed from suet. It is solid at room temperature. Unlike suet, tallow can be stored for extended periods without the need for refrigeration to prevent decomposition, provided it is kept in an airtight container to prevent oxidation.In industry,...
. The cetyl
Cetyl alcohol
Cetyl alcohol, also known as 1-hexadecanol and palmityl alcohol, is a fatty alcohol with the chemical formula CH315OH. At room temperature, cetyl alcohol takes the form of a waxy white solid or flakes....
ester of palmitic acid (cetyl palmitate) occurs in spermiceti. It was discovered by Edmond Frémy
Edmond Fremy
Edmond Frémy was a French chemist. He is perhaps best known today for Frémy's salt, a strong oxidizing agent which he discovered in 1845...
in 1840, in saponified
Saponification
Saponification is a process that produces soap, usually from fats and lye. In technical terms, saponification involves base hydrolysis of triglycerides, which are esters of fatty acids, to form the sodium salt of a carboxylate. In addition to soap, such traditional saponification processes...
palm oil.
Palmitic acid is prepared by treating fats and oils with water at a high pressure and temperature (above 200 °C), leading to the hydrolysis
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...
of triglyceride
Triglyceride
A triglyceride is an ester derived from glycerol and three fatty acids. There are many triglycerides, depending on the oil source, some are highly unsaturated, some less so....
s. The resulting mixture is then distilled.
Biochemistry
Excess carbohydrates in the body are converted to palmitic acid. Palmitic acid is the first fatty acid produced during fatty acid synthesisFatty acid synthesis
Fatty acid synthesis is the creation of fatty acids from acetyl-CoA and malonyl-CoA precursors through action of enzymes called fatty acid synthases...
and from which longer fatty acids can be produced. Palmitate negatively feeds back on acetyl-CoA carboxylase
Acetyl-CoA carboxylase
Acetyl-CoA carboxylase is a biotin-dependent enzyme that catalyzes the irreversible carboxylation of acetyl-CoA to produce malonyl-CoA through its two catalytic activities, biotin carboxylase and carboxyltransferase...
(ACC), which is responsible for converting acetyl-CoA to malonyl-CoA, which in turn is used to add to the growing acyl chain, thus preventing further palmitate generation. In biology, some proteins are modified by the addition of a palmitoyl group in a process known as palmitoylation
Palmitoylation
S-Palmitoylation is the covalent attachment of fatty acids, such as palmitic acid, to cysteine residues of membrane proteins. The precise function of palmitoylation depends on the particular protein being considered. Palmitoylation enhances the hydrophobicity of proteins and contributes to their...
. Palmitoylation is important for membrane localisation of many proteins.
Applications
Palmitic acid is mainly used to produce soaps, cosmetics, and release agentRelease agent
A release agent is a chemical used to get a slip effect. It can provide a solution in processes involving mold release, die-cast release, plastic release, and tire and web release.-Concrete:...
s. For these applications, the palmitic acid is neutralized with sodium hydroxide to give sodium palmitate. The most common route to sodium palmitate is saponification
Saponification
Saponification is a process that produces soap, usually from fats and lye. In technical terms, saponification involves base hydrolysis of triglycerides, which are esters of fatty acids, to form the sodium salt of a carboxylate. In addition to soap, such traditional saponification processes...
, in which palm oil, rendered from the coconut palm nut, is treated with concentrated sodium hydroxide (in the form of caustic soda or lye), which causes hydrolysis
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...
of the ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
groups. This procedure splits the ester groups in the oil into glycerol
Glycerol
Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol backbone is central to all lipids...
and sodium palmitate.
Because it is inexpensive and benign, palmitic acid and its sodium salt find wide use including foodstuffs. Sodium palmitate is permitted as a natural additive in organic
Organic certification
Organic certification is a certification process for producers of organic food and other organic agricultural products. In general, any business directly involved in food production can be certified, including seed suppliers, farmers, [food] processors, retailers and restaurants.Requirements vary...
products.
Hydrogenation
Hydrogenation
Hydrogenation, to treat with hydrogen, also a form of chemical reduction, is a chemical reaction between molecular hydrogen and another compound or element, usually in the presence of a catalyst. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically...
of palmitic acid yields cetyl alcohol
Cetyl alcohol
Cetyl alcohol, also known as 1-hexadecanol and palmityl alcohol, is a fatty alcohol with the chemical formula CH315OH. At room temperature, cetyl alcohol takes the form of a waxy white solid or flakes....
, which is used to produce detergents and cosmetics.
Recently, a long-acting antipsychotic medication, paliperidone
Paliperidone
Paliperidone , also known as 9-hydroxyrisperidone, is an atypical antipsychotic developed by Janssen Pharmaceutica. Invega is an extended release formulation of paliperidone that uses the OROS extended release system to allow for once-daily dosing...
palmitate (marketed as INVEGA Sustenna), used in the treatment of schizophrenia
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
, has been synthesized using the oily palmitate ester as a long-acting release carrier medium when injected intramuscularly. The underlying method of drug delivery is similar to that used with decanoic acid
Decanoic acid
Decanoic acid, or capric acid, is a saturated fatty acid.Its formula is CH38COOH. Salts and esters of decanoic acid are called decanoates...
to deliver long-acting depot medication, in particular, neuroleptics such as haloperidol
Haloperidol
Haloperidol is a typical antipsychotic. It is in the butyrophenone class of antipsychotic medications and has pharmacological effects similar to the phenothiazines....
decanoate.
Napalm
Aluminum salts of palmitic acid and naphthenic acidNaphthenic acid
Naphthenic acid is the name for an unspecific mixture of several cyclopentyl and cyclohexyl carboxylic acids with molecular weight of 120 to well over 700 atomic mass units. The main fraction are carboxylic acids with a carbon backbone of 9 to 20 carbons. The naphtha fraction of the crude oil...
were combined during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
to produce napalm concentrate (aluminum naphthenate and aluminum palmitate).
Dietary effect
According to the World Health OrganizationWorld Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...
, evidence is "convincing" that consumption of palmitic acid increases risk of developing cardiovascular diseases, placing it in the same evidence category as trans fatty acids. The report does not cite any studies that actually found a link between palmitic acid intake and patient outcomes. Another study showed that palmitic acid has no hypercholesterolaemic effect if intake of linoleic acid
Linoleic acid
Linoleic acid is an unsaturated n-6 fatty acid. It is a colorless liquid at room temperature. In physiological literature, it has a lipid number of 18:2...
, an essential fatty acid, is greater than 4.5% of energy. On the other hand, it was shown that, if the diet contains trans fatty acids, the health effects are negative, causing an LDL cholesterol increase and HDL cholesterol decrease.
Retinyl palmitate
Retinyl palmitate
Retinyl palmitate, or vitamin A palmitate, is the ester of retinol and palmitic acid, with formula C36H60O2.Palmitate is the major component of palm oil...
is an antioxidant
Antioxidant
An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...
and a source of vitamin A
Vitamin A
Vitamin A is a vitamin that is needed by the retina of the eye in the form of a specific metabolite, the light-absorbing molecule retinal, that is necessary for both low-light and color vision...
added to low fat milk to replace the vitamin content lost through the removal of milk fat. Palmitate is attached to the alcohol form of vitamin A, retinol
Retinol
Retinol is one of the animal forms of vitamin A. It is a diterpenoid and an alcohol. It is convertible to other forms of vitamin A, and the retinyl ester derivative of the alcohol serves as the storage form of the vitamin in animals....
, to make vitamin A stable in milk.