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A dicarboxylic acid is an organic compound containing two carboxyl functional groups (-COOH). 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.〔Boy Cornils, Peter Lappe "Dicarboxylic Acids, Aliphatic" in Ullmann's Encyclopedia of Industrial Chemistry 2006, Wiley-VCH, Weinheim. 〕 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 (in Latin adipis, is fat), 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 (ricinoleic acid) 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 (Greek pimelh, fat), 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 (Latin suber). 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 (nylon variants). Azelaic acid is the best known dicarboxylic acid. Its name stems from the action of nitric acid (azote, nitrogen, or azotic, nitric) 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 (for vinyl chloride resins, rubber), lubricants and greases. Azelaic acid is now used in cosmetics (treatment of acne). 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 (tallow).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 (''Candida'' sp.) 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 (nylon-6,12), 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'' (Apiaceae). Japan wax is a mixture containing triglycerides of C21, C22 and C23 dicarboxylic acids obtained from the sumac tree (''Rhus'' sp.). A large survey of the dicarboxylic acids present in Mediterranean nuts revealed unusual components. A total of 26 minor acids (from 2 in pecan to 8% in peanut) 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 (>C20) are found in suberin present at vegetal surfaces (outer bark, root epidermis). 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 (< 5%) in plant cutin, except in ''Arabidopsis thaliana'' where their content can be higher than 50%. It was shown that hyperthermophilic microorganisms specifically contained a large variety of dicarboxylic acids.〔 〕 This is probably the most important difference between these microorganisms and other marine bacteria. Dioic fatty acids from C16 to C22 were found in an hyperthermophilic archaeon, ''Pyrococcus furiosus''. Short and medium chain (up to 11 carbon atoms) dioic acids have been discovered in Cyanobacteria of the genus ''Aphanizomenon''. Dicarboxylic acids may be produced by ω-oxidation of fatty acids during their catabolism. It was discovered that these compounds appeared in urine after administration of tricaprin and triundecylin. Although the significance of their biosynthesis remains poorly understood, it was demonstrated that ω-oxidation occurs in rat liver but at a low rate, needs oxygen, NADPH and cytochrome P450. It was later shown that this reaction is more important in starving or diabetic animals where 15% of palmitic acid is subjected to ω-oxidation and then tob-oxidation,this generates malonyl-coA which is further used in saturated fatty acid synthesis. The determination of the dicarboxylic acids generated by permanganate-periodate oxidation of monoenoic fatty acids was useful to study the position of the double bond in the carbon chain. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Dicarboxylic acid」の詳細全文を読む スポンサード リンク
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