A dicarboxylic acid is an organic compound containing two carboxyl
functional groups. The general molecular formula for dicarboxylic acids can be
written as HO2C-R-CO2H, where R can be aliphatic or aromatic. In general,
dicarboxylic acids show similar chemical behavior and reactivity to
monocarboxylic acids. Dicarboxylic acids are also used in the preparation of
copolymers such as polyamides and polyesters. The most widely used
dicarboxylic acid in the industry is adipic acid, which is a precursor used
in the production of nylon. Other examples of dicarboxylic acids include
aspartic acid and glutamic acid, two amino acids in the human body.
Linear saturated dicarboxylic acids General formula HO2C(CH2)nCO2H. The
PubChem link gives access to a wealth of information on the compound.
Many linear dicarboxylic acids with the formula HOOC-(CH2)n-COOH are found in
nature. They are also known as α,ω- dicarboxylic acids, meaning that the two
carboxylate groups are at the two ends of the aliphatic chain of methylene
groups. A mnemonic for the first nine is Oh My Such Good Apple Pie, Soup And
Syrup. The long-chain members are classed as lipids.
Adipic acid Despite its name, this acid is not a normal constituent of natural
lipids but is a product of oxidative rancidity. It was first obtained by
oxidation of castor oil with nitric acid. It is now produced industrially by
oxidation of cyclohexanol or cyclohexane, mainly for the production
of Nylon 6-6. It has several other industrial uses in the production of
adhesives, plasticizers, gelatinizing agents, hydraulic fluids, lubricants,
emollients, polyurethane foams, leather tanning, urethane and also as an
acidulant in foods. Pimelic acid, was also first isolated
from oxidized oil. Derivatives of pimelic acid are involved in the
biosynthesis of lysine. Suberic acid it was first produced by
nitric acid oxidation of cork. This acid is also produced when castor oil is
oxidised. Suberic acid was used in the manufacture of alkyd resins and in the
synthesis of polyamides. Azelaic acid is the best known
dicarboxylic acid. Its name stems from the action of nitric acid oxidation of
oleic acid or elaidic acid. It was detected among products of rancid fats.
Its origin explains for its presence in poorly preserved samples of linseed oil
and in specimens of ointment removed from Egyptian tombs 5000 years old.
Azelaic acid was prepared by oxidation of oleic acid with potassium
permanganate, but now by oxidative cleavage of oleic acid with chromic acid
or by ozonolysis. Azelaic acid is used, as simple esters or branched-chain
esters) in the manufacture of plasticizers, lubricants and greases.
Azelaic acid is now used in cosmetics. It displays bacteriostatic and
bactericidal properties against a variety of aerobic and anaerobic
micro-organisms present on acne-bearing skin. . Azelaic acid was identified as a
molecule that accumulated at elevated levels in some parts of plants and was
shown to be able to enhance the resistance of plants to infections.
Sebacic acid, named from sebum.Thenard isolated this compound from distillation
products of beef tallow in 1802. It is produced industrially by alkali fission
of castor oil. Sebacic acid and its derivatives have a variety of industrial
uses as plasticizers, lubricants, diffusion pump oils, cosmetics, candles,
etc. It is also used in the synthesis of polyamide, as nylon, and of alkyd
resins. An isomer, isosebacic acid, has several applications in the manufacture
of vinyl resin plasticizers, extrusion plastics, adhesives, ester lubricants,
polyesters, polyurethane resins and synthetic rubber.
Brassylic acid can be produced chemically from erucic acid by
ozonolysis but also by microorganisms from tridecane. This diacid is produced
on a small commercial scale in Japan for the manufacture of fragrances.
Dodecanedioic acid is used in the production of nylon, polyamides,
coatings, adhesives, greases, polyesters, dyestuffs, detergents, flame
retardants, and fragrances. It is now produced by fermentation of long-chain
alkanes with a specific strain of Candida tropicalis. Traumatic acid is
its monounsaturated counterpart. Thapsic acid was isolated from the dried
roots of the Mediterranean "deadly carrot", Thapsia garganica.
Japan wax is a mixture containing triglycerides of C21, C22 and C23
dicarboxylic acids obtained from the sumac tree.
A large survey of the dicarboxylic acids present in Mediterranean nuts revealed
unusual components. A total of 26 minor acids were determined : 8 species
derived from succinic acid, likely in relation with photosynthesis, and 18
species with a chain from 5 to 22 carbon atoms. Higher weight acids are found in
suberin present at vegetal surfaces. C16 to C26 a, ω-dioic acids are considered
as diagnostic for suberin. With C18:1 and C18:2, their content amount from 24
to 45% of whole suberin. They are present at low levels (