Triglyceride Structural Formulae V.1.png
   HOME

TheInfoList



OR:

A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids (from ''
tri- Numeral or number prefixes are prefixes derived from numerals or occasionally other numbers. In English and many other languages, they are used to coin numerous series of words. For example: * unicycle, bicycle, tricycle (1-cycle, 2-cycle, 3-cyc ...
'' and '' glyceride''). Triglycerides are the main constituents of body fat in humans and other vertebrates, as well as
vegetable fat Vegetable oils, or vegetable fats, are oils extracted from seeds or from other parts of fruits. Like animal fats, vegetable fats are ''mixtures'' of triglycerides. Soybean oil, grape seed oil, and cocoa butter are examples of seed oils, or fats ...
. They are also present in the blood to enable the bidirectional transference of adipose fat and blood glucose from the liver, and are a major component of human skin oils. Many types of triglycerides exist. One specific classification focuses on
saturated and unsaturated In chemistry, a saturated compound is a chemical compound (or ion) that resists the addition reactions, such as hydrogenation, oxidative addition, and binding of a Lewis base. The term is used in many contexts and for many classes of chemical co ...
types.
Saturated fat A saturated fat is a type of fat in which the fatty acid chains have all single bonds. A fat known as a glyceride is made of two kinds of smaller molecules: a short glycerol backbone and fatty acids that each contain a long linear or branched c ...
s have ''no'' C=C groups;
unsaturated fat An unsaturated fat is a fat or fatty acid in which there is at least one double bond within the fatty acid chain. A fatty acid chain is monounsaturated if it contains one double bond, and polyunsaturated if it contains more than one double bond. ...
s feature one or more C=C groups. Unsaturated fats tend to have a lower melting point than saturated analogues; as a result, they are often
liquid A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure. As such, it is one of the four fundamental states of matter (the others being solid, gas, a ...
at room temperature.


Chemical structure

Triglycerides are tri- esters consisting of a glycerol bound to three fatty acid molecules.
Alcohols In chemistry, an alcohol is a type of organic compound that carries at least one hydroxyl () functional group bound to a saturated carbon atom. The term ''alcohol'' originally referred to the primary alcohol ethanol (ethyl alcohol), which is ...
have a hydroxyl (HO–) group. Organic acids have a carboxyl (–COOH) group. Alcohols and organic acids join to form esters. The glycerol molecule has three hydroxyl (HO–) groups and each fatty acid has a carboxyl group (–COOH). In triglycerides, the hydroxyl groups of the glycerol join the carboxyl groups of the fatty acid to form ester bonds: :HOCH2CH(OH)CH2OH + RCO2H + R′CO2H + R″CO2H → RCO2CH2CH(O2CR′)CH2CO2R″ + 3H2O The three fatty acids (RCO2H, R′CO2H, R″CO2H in the above equation) are usually different, as many kinds of triglycerides are known. The chain lengths of the fatty acids in naturally occurring triglycerides vary, but most contain 16, 18, or 20 carbon atoms. Natural fatty acids found in plants and animals are typically composed of only even numbers of carbon atoms, reflecting the pathway for their biosynthesis from the two-carbon building-block acetyl CoA. Bacteria, however, possess the ability to synthesise odd- and branched-chain fatty acids. As a result, ruminant animal fat contains odd-numbered fatty acids, such as 15, due to the action of bacteria in the rumen. Many fatty acids are unsaturated; some are polyunsaturated (e.g., those derived from linoleic acid). Most natural fats contain a complex mixture of individual triglycerides. Because of this, they melt over a broad range of temperatures. Cocoa butter is unusual in that it is composed of only a few triglycerides, derived from
palmitic Palmitic acid (hexadecanoic acid in IUPAC nomenclature) is a fatty acid with a 16-carbon chain. It is the most common saturated fatty acid found in animals, plants and microorganisms.Gunstone, F. D., John L. Harwood, and Albert J. Dijkstra. The Li ...
,
oleic Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish. In chemical terms, oleic acid is classified as a monounsaturated omega ...
, and
stearic acid Stearic acid ( , ) is a saturated fatty acid with an 18-carbon chain. The IUPAC name is octadecanoic acid. It is a waxy solid and its chemical formula is C17H35CO2H. Its name comes from the Greek word στέαρ "''stéar''", which means tallow. ...
s in the 1-, 2-, and 3-positions of glycerol, respectively.


Homo- and heterotriglycerides

The simplest triglycerides are those where the three fatty acids are identical. Their names indicate the fatty acid:
stearin Stearin , or tristearin, or glyceryl tristearate is an odourless, white powder. It is a triglyceride derived from three units of stearic acid. Most triglycerides are derived from at least two and more commonly three different fatty acids. Like o ...
derived from stearic acid, palmitin derived from palmitic acid, etc. These compounds can be obtained in three crystalline forms ( polymorphs): α, β, and β′, the three forms differing in their melting points. If the first and third fatty acids on the glycerol differ, then the triglyceride is chiral.


Conformation

The shape of fat and fatty acid molecules is usually not well-defined. Any two parts of a molecule that are connected by just one single bond are free to rotate about that bond. Thus a fatty acid molecule with ''n'' simple bonds can be deformed in ''n''-1 independent ways (counting also rotation of the terminal methyl group). Such rotation cannot happen across a double bond, except by breaking and then reforming it with one of the halves of the molecule rotated by 180 degrees, which requires crossing a significant
energy barrier In chemistry and physics, activation energy is the minimum amount of energy that must be provided for compounds to result in a chemical reaction. The activation energy (''E''a) of a reaction is measured in joules per mole (J/mol), kilojoules p ...
. Thus a fat or fatty acid molecule with double bonds (excluding at the very end of the chain) can have multiple cis–trans isomers with significantly different chemical and biological properties. Each double bond reduces the number of conformational
degrees of freedom Degrees of freedom (often abbreviated df or DOF) refers to the number of independent variables or parameters of a thermodynamic system. In various scientific fields, the word "freedom" is used to describe the limits to which physical movement or ...
by one. Each triple bond forces the four nearest carbons to lie in a straight line, removing two degrees of freedom. It follows that depictions of "saturated" fatty acids with no double bonds (like stearic) having a "straight zig-zag" shape, and those with one ''cis'' bond (like oleic) being bent in an "elbow" shape are somewhat misleading. While the latter are a little less flexible, both can be twisted to assume similar straight or elbow shapes. In fact, outside of some specific contexts like crystals or bilayer membranes, both are more likely to be found in randomly contorted configurations than in either of those two shapes.


Examples

Stearic acid is a saturated fatty acid (with only single bonds) found in animal fats, and is the intended product in full hydrogenation. Oleic acid has a double bond (thus being "unsaturated") with ''cis'' geometry about midway in the chain; it makes up 55–80% of olive oil. Elaidic acid is its ''trans'' isomer; it may be present in partially hydrogenated vegetable oils, and also occurs in the fat of the
durian The durian (, ) is the edible fruit of several tree species belonging to the genus ''Durio''. There are 30 recognised ''Durio'' species, at least nine of which produce edible fruit. ''Durio zibethinus'', native to Borneo and Sumatra, is the onl ...
fruit (about 2%) and in milk fat (less than 0.1%). Vaccenic acid is another ''trans'' acid that differs from elaidic only in the position of the double bond; it also occurs in milk fat (about 1–2%).


Nomenclature


Common fat names

Fats are usually named after their source (like
olive oil Olive oil is a liquid fat obtained from olives (the fruit of ''Olea europaea''; family Oleaceae), a traditional tree crop of the Mediterranean Basin, produced by pressing whole olives and extracting the oil. It is commonly used in cooking: f ...
, cod liver oil,
shea butter Shea butter (, , or ; ) is a fat extracted from yellow the nut of the African shea tree (''Vitellaria paradoxa''). It is ivory in color when raw and commonly dyed yellow with borututu root or palm oil. It is widely used in cosmetics as a moi ...
,
tail fat Tail fat is the fat of some breeds of sheep, especially of fat-tailed sheep. It is fat accumulated in baggy deposits in the hind parts of a sheep on both sides of its tail and on the first 3–5 vertebrae of the tail. The weight of this part of a ...
) or have traditional names of their own (like butter, lard,
ghee Ghee is a type of clarified butter, originating from India. It is commonly used in India for cooking, as a traditional medicine, and for religious rituals. Description Ghee is typically prepared by simmering butter, which is churned from c ...
, and
margarine Margarine (, also , ) is a spread used for flavoring, baking, and cooking. It is most often used as a substitute for butter. Although originally made from animal fats, most margarine consumed today is made from vegetable oil. The spread was orig ...
). Some of these names refer to products that contain substantial amounts of other components besides fats proper.


Chemical fatty acid names

In chemistry and biochemistry, dozens of saturated fatty acids and of hundreds of unsaturated ones have traditional scientific/technical names usually inspired by their source fats (butyric, caprylic, stearic, oleic,
palmitic Palmitic acid (hexadecanoic acid in IUPAC nomenclature) is a fatty acid with a 16-carbon chain. It is the most common saturated fatty acid found in animals, plants and microorganisms.Gunstone, F. D., John L. Harwood, and Albert J. Dijkstra. The Li ...
, and nervonic), but sometimes their discoverer (
mead Mead () is an alcoholic beverage made by fermenting honey mixed with water, and sometimes with added ingredients such as fruits, spices, grains, or hops. The alcoholic content ranges from about 3.5% ABV to more than 20%. The defining character ...
, osbond). A triglyceride would then be named as an ester of those acids, such as "glyceryl 1,2-dioleate 3-palmitate".N. Koeniger and H. J. Veith (1983): "Glyceryl-1,2-dioleate-3-palmitate, a brood pheromone of the honey bee (''Apis mellifera'' L.)". ''Experientia'', volume 39, pages 1051–1052


IUPAC

In the general chemical nomenclature developed by the International Union of Pure and Applied Chemistry (IUPAC), the recommended name of a fatty acid, derived from the name of the corresponding hydrocarbon, completely describes its structure, by specifying the number of carbons and the number and position of the double bonds. Thus, for example, oleic acid would be called "(9Z)-octadec-9-enoic acid", meaning that it has an 18 carbon chain ("octadec") with a carboxyl at one end ("oic") and a double bond at carbon 9 counting from the carboxyl ("9-en"), and that the configuration of the single bonds adjacent to that double bond is ''cis'' ("(9Z)") The IUPAC nomenclature can also handle branched chains and derivatives where hydrogen atoms are replaced by other chemical groups. A triglyceride would then be named according to general ester rules as, for example, "propane-1,2,3-tryl 1,2-bis((9Z)-octadec-9-enoate) 3-(hexadecanoate)".


Fatty acid code

A notation specific for fatty acids with unbranched chain, that is as precise as the IUPAC one but easier to parse, is a code of the form ": cis- trans-", where is the number of carbons (including the carboxyl one), is the number of double bonds, is a list of the positions of the ''cis'' double bonds, and is a list of the positions of the ''trans'' bonds. Either list and the label is omitted if there are no bonds of that type. Thus, for example, the codes for stearic, oleic, elaidic, and vaccenic acids would be "18:0", "18:1 cis-9", "18:1 trans-9", and "18:1 trans-11", respectively. The code for α-oleostearic acid, which is "(9E,11E,13Z)-octadeca-9,11,13-trienoic acid" in the IUPAC nomenclature, has the code "18:3 trans-9,11 cis-13"


Classification


By chain length

Fats can be classified according to the lengths of the carbon chains of their constituent fatty acids. Most chemical properties, such as melting point and acidity, vary gradually with this parameter, so there is no sharp division. Chemically,
formic acid Formic acid (), systematically named methanoic acid, is the simplest carboxylic acid, and has the chemical formula HCOOH and structure . It is an important intermediate in chemical synthesis and occurs naturally, most notably in some ants. Es ...
(1 carbon) and
acetic acid Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component ...
(2 carbons) could be viewed as the shortest fatty acids; then
triformin Triformin (glycerin triformate) is the triester of glycerol Glycerol (), also called glycerine in British English and glycerin in American English, is a simple triol compound. It is a colorless, odorless, viscous liquid that is sweet-tasti ...
would be the simplest triglyceride. However, the terms "fatty acid" and "fat" are usually reserved for compounds with substantially longer chains. A division commonly made in biochemistry and nutrition is: * Short-chain fatty acid (SCFA) with fewer than six carbons (e. g.
butyric acid Butyric acid (; from grc, βούτῡρον, meaning "butter"), also known under the systematic name butanoic acid, is a straight-chain alkyl carboxylic acid with the chemical formula CH3CH2CH2CO2H. It is an oily, colorless liquid with an unple ...
). * Medium-chain fatty acid (MCFA) with 6 to 12 carbons (e.g.
capric acid Capric acid, also known as decanoic acid or decylic acid, is a saturated fatty acid, medium-chain fatty acid (MCFA), and carboxylic acid. Its formula is CH3(CH2)8COOH. Salts and esters of decanoic acid are called caprates or decanoates. The term ...
). * Long-chain fatty acids (LCFA) with 13 to 21 carbons (e.g. petroselinic acid). * Very long chain fatty acids (VLCFA) with 22 or more carbons (e. g. cerotic acid with 26) A triglyceride molecule may have fatty acid elements of different lengths, and a fat product will often be a mix of various triglycerides. Most fats found in food, whether vegetable or animal, are made up of medium to long-chain fatty acids, usually of equal or nearly equal length.


Saturated and unsaturated fats

For human nutrition, an important classification of fats is based on the number and position of double bonds in the constituent fatty acids. Saturated fat has a predominance of saturated fatty acids, without any double bonds, while unsaturated fat has predominantly unsaturated acids with double bonds. (The names refer to the fact that each double bond means two fewer hydrogen atoms in the chemical formula. Thus, a saturated fatty acid, having no double bonds, has the maximum number of hydrogen atoms for a given number of carbon atomsthat is, it is "saturated" with hydrogen atoms.) Unsaturated fatty acids are further classified into monounsaturated (MUFAs), with a single double bond, and polyunsaturated (PUFAs), with two or more. Natural fats usually contain several different saturated and unsaturated acids, even on the same molecule. For example, in most vegetable oils, the saturated
palmitic Palmitic acid (hexadecanoic acid in IUPAC nomenclature) is a fatty acid with a 16-carbon chain. It is the most common saturated fatty acid found in animals, plants and microorganisms.Gunstone, F. D., John L. Harwood, and Albert J. Dijkstra. The Li ...
(C16:0) and
stearic Stearic acid ( , ) is a saturated fatty acid with an 18-carbon chain. The IUPAC name is octadecanoic acid. It is a waxy solid and its chemical formula is C17H35CO2H. Its name comes from the Greek word στέαρ "''stéar''", which means tallow. ...
(C18:0) acid residues are usually attached to positions 1 and 3 (sn1 and sn3) of the glycerol hub, whereas the middle position (sn2) is usually occupied by an unsaturated one, such as
oleic Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish. In chemical terms, oleic acid is classified as a monounsaturated omega ...
(C18:1, ω–9) or
linoleic Linoleic acid (LA) is an organic compound with the formula COOH(CH2)7CH=CHCH2CH=CH(CH2)4CH3. Both alkene groups are ''cis''. It is a fatty acid sometimes denoted 18:2 (n-6) or 18:2 ''cis''-9,12. A linoleate is a salt or ester of this acid. L ...
(C18:2, ω–6).) While it is the ''nutritional'' aspects of polyunsaturated fatty acids that are generally of greatest interest, these materials also have non-food applications. They include the drying oils, such as linseed (flax seed), tung, poppyseed, perilla, and walnut oil, which polymerize on exposure to oxygen to form solid films, and are used to make
paint Paint is any pigmented liquid, liquefiable, or solid mastic composition that, after application to a substrate in a thin layer, converts to a solid film. It is most commonly used to protect, color, or provide texture. Paint can be made in many ...
s and
varnish Varnish is a clear transparent hard protective coating or film. It is not a stain. It usually has a yellowish shade from the manufacturing process and materials used, but it may also be pigmented as desired, and is sold commercially in various ...
es. Saturated fats generally have a higher melting point than unsaturated ones with the same molecular weight, and thus are more likely to be solid at room temperature. For example, the animal fats tallow and
lard Lard is a semi-solid white fat product obtained by rendering the fatty tissue of a pig.Lard
entry in the o ...
are high in saturated fatty acid content and are solids. Olive and linseed oils on the other hand are unsaturated and liquid. Unsaturated fats are prone to oxidation by air, which causes them to become rancid and inedible. The double bonds in unsaturated fats can be converted into single bonds by reaction with hydrogen effected by a catalyst. This process, called hydrogenation, is used to turn vegetable oils into solid or semisolid
vegetable fat Vegetable oils, or vegetable fats, are oils extracted from seeds or from other parts of fruits. Like animal fats, vegetable fats are ''mixtures'' of triglycerides. Soybean oil, grape seed oil, and cocoa butter are examples of seed oils, or fats ...
s like
margarine Margarine (, also , ) is a spread used for flavoring, baking, and cooking. It is most often used as a substitute for butter. Although originally made from animal fats, most margarine consumed today is made from vegetable oil. The spread was orig ...
, which can substitute for tallow and butter and (unlike unsaturated fats) can be stored indefinitely without becoming rancid. However, partial hydrogenation also creates some unwanted ''trans'' acids from ''cis'' acids. In cellular metabolism, unsaturated fat molecules yield slightly less energy (i.e., fewer calories) than an equivalent amount of saturated fat. The heats of combustion of saturated, mono-, di-, and tri-unsaturated 18-carbon fatty acid esters have been measured as 2859, 2828, 2794, and 2750 kcal/mol, respectively; or, on a weight basis, 10.75, 10.71, 10.66, and 10.58 kcal/ga decrease of about 0.6% for each additional double bond. The greater the degree of unsaturation in a fatty acid (i.e., the more double bonds in the fatty acid) the more vulnerable it is to
lipid peroxidation Lipid peroxidation is the chain of reactions of oxidative degradation of lipids. It is the process in which radical (chemistry), free radicals "steal" electrons from the lipids in cell membranes, resulting in cell damage. This process proceeds by ...
(
rancidity Rancidification is the process of complete or incomplete autoxidation or hydrolysis of fats and oils when exposed to air, light, moisture, or bacterial action, producing short-chain aldehydes, ketones and free fatty acids. When these processes oc ...
).
Antioxidant Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricant ...
s can protect unsaturated fat from lipid peroxidation.


Cis and trans fats

Another important classification of unsaturated fatty acids considers the ''cis''–''trans'' isomerism, the spatial arrangement of the C–C
single bond In chemistry, a single bond is a chemical bond between two atoms involving two valence electrons. That is, the atoms share one pair of electrons where the bond forms. Therefore, a single bond is a type of covalent bond. When shared, each of th ...
s adjacent to the double bonds. Most unsaturated fatty acids that occur in nature have those bonds in the ''cis'' ("same side") configuration. Partial hydrogenation of ''cis'' fats can turn some of their fatty acids into ''trans'' ("opposite sides") variety. Elaidic acid is the ''trans'' isomer of oleic acid, one of the most common fatty acids in human diet. The single change of configuration in one double bond causes them to have different chemical and physical properties. Elaidic acid has a much higher melting point than oleic acid, 45
°C The degree Celsius is the unit of temperature on the Celsius scale (originally known as the centigrade scale outside Sweden), one of two temperature scales used in the International System of Units (SI), the other being the Kelvin scale. The ...
instead of 13.4 °C. This difference is commonly attributed to the supposed ability of the trans molecules to pack more tightly, forming a solid that is more difficult to break apart.


Omega number

Another classification considers the position of the double bonds relative to the ''end'' of the chain (opposite to the carboxyl group). The position is denoted by "ω−''k''" or "n−''k''", meaning that there is a double bond between carbons ''k'' and ''k''+1 counted from 1 at that end. For example, alpha-Linolenic acid is a "ω−3" or "n−3" acid, meaning that there is a double bond between the third and fourth carbons, counted from that end; that is, its
structural formula The structural formula of a chemical compound is a graphic representation of the molecular structure (determined by structural chemistry methods), showing how the atoms are possibly arranged in the real three-dimensional space. The chemical bondi ...
ends with –CH=CH––.Karen Dooley (2008):
Omega-three fatty acids and diabetes
. Online article at th
University of Florida's UFHealt
website. Accessed on 2020-08-30.


Examples of saturated fatty acids

Some common examples of fatty acids: *
Butyric acid Butyric acid (; from grc, βούτῡρον, meaning "butter"), also known under the systematic name butanoic acid, is a straight-chain alkyl carboxylic acid with the chemical formula CH3CH2CH2CO2H. It is an oily, colorless liquid with an unple ...
with 4 carbon atoms (contained in butter) * Lauric acid with 12 carbon atoms (contained in
coconut oil frameless , right , alt = A cracked coconut and a bottle of coconut oil Coconut oil (or coconut butter) is an edible oil derived from the wick, meat, and milk of the coconut palm fruit. Coconut oil is a white solid fat; in warmer climates duri ...
, palm kernel oil, and
breast milk Breast milk (sometimes spelled as breastmilk) or mother's milk is milk produced by mammary glands located in the breast of a human female. Breast milk is the primary source of nutrition for newborns, containing fat, protein, carbohydrates ( lacto ...
) * Myristic acid with 14 carbon atoms (contained in cow's milk and dairy products) * Palmitic acid with 16 carbon atoms (contained in
palm oil Palm oil is an edible vegetable oil derived from the mesocarp (reddish pulp) of the fruit of the oil palms. The oil is used in food manufacturing, in beauty products, and as biofuel. Palm oil accounted for about 33% of global oils produced from ...
and
meat Meat is animal flesh that is eaten as food. Humans have hunted, farmed, and scavenged animals for meat since prehistoric times. The establishment of settlements in the Neolithic Revolution allowed the domestication of animals such as chic ...
) *
Stearic acid Stearic acid ( , ) is a saturated fatty acid with an 18-carbon chain. The IUPAC name is octadecanoic acid. It is a waxy solid and its chemical formula is C17H35CO2H. Its name comes from the Greek word στέαρ "''stéar''", which means tallow. ...
with 18 carbon atoms (also contained in
meat Meat is animal flesh that is eaten as food. Humans have hunted, farmed, and scavenged animals for meat since prehistoric times. The establishment of settlements in the Neolithic Revolution allowed the domestication of animals such as chic ...
and cocoa butter)


Examples of unsaturated fatty acids

* Myristoleic acid C14:1, ω−5, ''cis''-9-tetradecenoic acid *
Sapienic acid Sapienic acid is a fatty acid that is a major component of human sebum. Sapienic acid is a sebum fatty acid that is unique to humans (from whose scientific name it takes the root ''sapiens''). The equivalent fatty acid in mouse sebum is palmitolei ...
C16:1 ω−10, ''cis''-6-Hexadecenoic acid * Palmitoleic acid C16:1, ω−7 , ''cis''-9-hexadecenoic acid * Oleic acid C18:1 ω−9, ''cis''-9-octadecenoic acid * Petroselinic acid C18:1 ω−12, ''cis''-Octadec-6-enoic acid * ''cis''-Vaccenic acid, C18:1 ω−7), ''cis''-11-octadecenoic acid *
Vaccenic acid Vaccenic acid is a naturally occurring trans fatty acid. It is the predominant kind of trans-fatty acid found in human milk, in the fat of ruminants, and in dairy products such as milk, butter, and yogurt. Trans fat in human milk may depend on tr ...
C18:1 ω−7, ''trans''-11-octadecenoic acid * Elaidic acid 18:1 ω−9, ''trans''-9-octadecenoic acid (''trans''-oleic acid) * Linoleic acid *
Linolenic acid Linolenic acid is a type of naturally-occurring fatty acid. It can refer to either of two octadecatrienoic acids (i.e. with an 18-carbon chain and three double bonds, which are found in the '' cis'' configuration), or a mixture of the two. Lino ...
*
Paullinic acid Paullinic acid is an omega-7 fatty acid find in a variety of plant sources, including guarana (''Paullinia cupana'') from which it gets its name. It is one of a number of eicosenoic acid Eicosenoic acid may refer to one of three closely related ...
C20:1 ω−7, ''cis''-13-eicosenoic acid *
Gadoleic acid Gadoleic acid (20:1 n−11) is an unsaturated fatty acid. It is a prominent component of some fish oils including cod liver oil. It is one of a number of eicosenoic acids. Its name is derived from a combination of the genus for cod (''Gadus'') an ...
C20:1 ω−11, ''cis''-9-icosenoic acid * Gondoic acid 20:1 ω−9, ''cis''-11-eicosenoic acid * Erucic acid C22:1 ω−9, ''cis''-15-docosenoic acid * Brassidic acid C22:1 ω−9, ''trans''-15-docosenoic acid * Nervonic acid C24:1 ω−9, , ''cis''-15-tetracosenoic acid *
Arachidonic acid Arachidonic acid (AA, sometimes ARA) is a polyunsaturated omega-6 fatty acid 20:4(ω-6), or 20:4(5,8,11,14). It is structurally related to the saturated arachidic acid found in cupuaçu butter. Its name derives from the New Latin word ''arachi ...


Industrial uses

Linseed oil and related oils are important components of useful products used in oil paints and related coatings. Linseed oil is rich in di- and tri-unsaturated fatty acid components, which tend to harden in the presence of oxygen. This heat-producing hardening process is peculiar to these so-called ''drying oils''. It is caused by a polymerization process that begins with oxygen molecules attacking the carbon backbone. Triglycerides are also split into their components via transesterification during the manufacture of biodiesel. The resulting fatty acid esters can be used as fuel in diesel engines. The glycerin has many uses, such as in the manufacture of food and in the production of pharmaceuticals.


Staining

Staining Staining is a technique used to enhance contrast in samples, generally at the microscopic level. Stains and dyes are frequently used in histology (microscopic study of biological tissues), in cytology (microscopic study of cells), and in the ...
for fatty acids, triglycerides, lipoproteins, and other lipids is done through the use of lysochromes (fat-soluble dyes). These dyes can allow the qualification of a certain fat of interest by staining the material a specific color. Some examples: Sudan IV,
Oil Red O Oil Red O (Solvent Red 27, Sudan Red 5B, C.I. 26125, C26H24N4O) is a lysochrome (fat-soluble dye) diazo dye used for staining of neutral triglycerides and lipids on frozen sections and some lipoproteins on paraffin sections. It has the appearance o ...
, and
Sudan Black B Solvent Black 3 is an azo dye. It is a non-fluorescent, relatively thermostable lysochrome (fat-soluble dye) diazo dye used for staining of neutral triglycerides and lipids on frozen sections and some lipoproteins on paraffin sections. It has the a ...
.


Interactive pathway map


See also

*
Diglyceride acyltransferase Diglyceride acyltransferase (or O-acyltransferase), DGAT, catalyzes the formation of triglycerides from diacylglycerol and fatty acyl-CoA]. The reaction catalyzed by DGAT is considered the terminal and only committed step in triglyceride synth ...
, enzyme responsible for triglyceride biosynthesis *
Medium-chain triglycerides Medium-chain triglycerides (MCTs) are triglycerides with two or three fatty acids having an aliphatic compound, aliphatic tail of 6–12 carbon atoms, i.e. medium-chain fatty acids (MCFAs). Rich food sources for commercial extraction of MCTs inclu ...
* Lipid profile * Lipids *
Vertical auto profile The vertical auto profile (VAP) test is a cholesterol, lipid and lipoprotein A lipoprotein is a biochemical assembly whose primary function is to transport hydrophobic lipid (also known as fat) molecules in water, as in blood plasma or other ...


References


External links


Lowering Triglycerides
(EMedicineHealth.com; October 2020) {{Authority control Lipid disorders Esters