Isanolic acid is a linear
fatty acid
In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated and unsaturated compounds#Organic chemistry, saturated or unsaturated. Most naturally occurring fatty acids have an ...
composed of 18 carbon atoms, with two
triple bond
A triple bond in chemistry is a chemical bond between two atoms involving six Electron pair bond, bonding electrons instead of the usual two in a covalent bond, covalent single bond. Triple bonds are stronger than the equivalent covalent bond, sin ...
s in the positions 9≡10 and 11≡12, a
double bond
In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...
in the position 17=18, and a hydroxyl-OH in the position 8. The acid is one of the rare polyacetylenic acids with conjugated triple bonds. The compound belongs to the family of
diynes and
enyne
An enyne is an organic compound containing a double bond (alkene) and a triple bond (alkyne). It is called a conjugated enyne when the double and triple bonds are conjugated.
The term is a contraction of the terms alkene and alkyne.
The si ...
s, as well as to the
alkyne
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Acetylene
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Propyne
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1-Butyne
In organic chemistry, an alkyne is an unsaturated hydrocarbon containing at least one carbon—carbon triple bond. The simplest acyclic alkynes with only one triple bond and n ...
and alkenoic acids.
The related compounds are
isanic and
ketoisanic acids, both containing only one
hydroxyl group
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ...
.
Discovery
The acid was initially isolated in 1937 by researchers A. Steger and J. van Loon from the seed oilof the tree ''
Ongokea gore'' or ''Ongokea klaineana'', a plant from equatorial Africa, called in the native language "boleka" or "isano"; a common name of isanolic acid comes from the latter. They also discovered
isanic acid. The oil seeds contain about 60% lipids. Since the compound is hard to isolate, various analyses have revealed non-homogeneous data on the concentration of isanolic acid in isano oil: from 3% to 44% of the total fatty acids.
Chemical properties
The compound can be detected in isane oil together with other hydroxylated acetylenic fatty acids, all with the hydroxyl in position 8.
The high degree of unsaturation suggests that oils with a high content of these conjugated acetylenic fatty acids are drying; the presence of hydroxylated fatty acids implies the possibility of forming atypical glycerides, such as
triglyceride
A triglyceride (from '' tri-'' and '' glyceride''; also TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids.
Triglycerides are the main constituents of body fat in humans and other vertebrates ...
s containing more than three
acyl group
In chemistry, an acyl group is a moiety derived by the removal of one or more hydroxyl groups from an oxoacid, including inorganic acids. It contains a double-bonded oxygen atom and an organyl group () or hydrogen in the case of formyl group ( ...
s.
Depending on the reaction conditions, isanolic acid reacts with
phenol
Phenol (also known as carbolic acid, phenolic acid, or benzenol) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile and can catch fire.
The molecule consists of a phenyl group () ...
to form enol ethers or vinyl aromatics.
References
{{Fatty acids
Alkenoic acids
Fatty acids
Conjugated diynes