In organic chemistry, a semialdehyde is a compound containing an aldehyde and a carboxylic acid functional groups. Semialdehydes are common in biochemistry. [1] The simplest semialdehydes have the formula HO2C(CH2)nCHO. As illustrated by the behavior of the smallest member, glyoxylic acid, semialdehydes often exist as hydrates (geminal diols) HO2C(CH2)nCH(OH)2.
Some of semialdehydes and their parent dicarboxylic acids are listed below.
Semialdehyde | Dicarboxylic acid |
---|---|
malonic semialdehyde | malonic acid |
tartronic semialdehyde | tartronic acid |
succinic semialdehyde | succinic acid |
methylmalonic semialdehyde | methylmalonic acid |
aspartic-4-semialdehyde | aspartic acid |
glutamic-1-semialdehyde | glutamic acid |
glutamic-5-semialdehyde | glutamic acid |
4-hydroxymuconic-semialdehyde | 4-Hydroxymuconic acid |
2-amino-3-carboxymuconic semialdehyde | 2-hydroxy-4-carboxymuconic acid |
alpha-aminoadipic semialdehyde | alpha-aminoadipic acid |
Although structurally related to semialdehydes, dicarboxylic acids are rarely biochemical precursors to them.
In polymer chemistry, condensation polymers are any kind of polymers whose process of polymerization involves a condensation reaction. Condensation polymers are formed by polycondensation, when the polymer is formed by condensation reactions between species of all degrees of polymerization, or by condensative chain polymerization, when the polymer is formed by sequential addition of monomers to an active site in a chain reaction. The main alternative forms of polymerization are chain polymerization and polyaddition, both of which give addition polymers.
Succinic acid is a dicarboxylic acid with the chemical formula (CH2)2(CO2H)2. In living organisms, succinic acid takes the form of an anion, succinate, which has multiple biological roles as a metabolic intermediate being converted into fumarate by the enzyme succinate dehydrogenase in complex 2 of the electron transport chain which is involved in making ATP, and as a signaling molecule reflecting the cellular metabolic state.
Erucic acid is a monounsaturated omega-9 fatty acid, denoted 22:1ω9. It has the chemical formula :CH3(CH2)7CH=CH(CH2)11CO2H. It is prevalent in wallflower seed and other plants in the family Brassicaceae, with a reported content of 20 to 54% in high erucic acid rapeseed oil and 42% in mustard oil. Erucic acid is also known as cis-13-docosenoic acid and the trans isomer is known as brassidic acid.
A diol is a chemical compound containing two hydroxyl groups. An aliphatic diol is also called a glycol. This pairing of functional groups is pervasive, and many subcategories have been identified.
In organic chemistry, an acyl halide is a chemical compound derived from an oxoacid by replacing a hydroxyl group with a halide group.
Adipic acid or hexanedioic acid is the organic compound with the formula (CH2)4(COOH)2. From an industrial perspective, it is the most important dicarboxylic acid: about 2.5 billion kilograms of this white crystalline powder are produced annually, mainly as a precursor for the production of nylon. Adipic acid otherwise rarely occurs in nature, but it is known as manufactured E number food additive E355. Salts and esters of adipic acid are known as adipates.
Acetic anhydride, or ethanoic anhydride, is the chemical compound with the formula (CH3CO)2O. Commonly abbreviated Ac2O, it is the simplest isolable anhydride of a carboxylic acid and is widely used as a reagent in organic synthesis. It is a colorless liquid that smells strongly of acetic acid, which is formed by its reaction with moisture in the air.
In organic chemistry, ozonolysis is an organic reaction where the unsaturated bonds are cleaved with ozone. Multiple carbon–carbon bond are replaced by carbonyl groups, such as aldehydes, ketones, and carboxylic acids. The reaction is predominantly applied to alkenes, but alkynes and azo compounds are also susceptible to cleavage. The outcome of the reaction depends on the type of multiple bond being oxidized and the work-up conditions.
Homoserine (also called isothreonine) is an α-amino acid with the chemical formula HO2CCH(NH2)CH2CH2OH. L-Homoserine is not one of the common amino acids encoded by DNA. It differs from the proteinogenic amino acid serine by insertion of an additional -CH2- unit into the backbone. Homoserine, or its lactone form, is the product of a cyanogen bromide cleavage of a peptide by degradation of methionine.
In organic chemistry, a dicarboxylic acid is an organic compound containing two carboxyl 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.
Pimelic acid is the organic compound with the formula HO2C(CH2)5CO2H. Pimelic acid is one CH
2 unit longer than a related dicarboxylic acid, adipic acid, a precursor to many polyesters and polyamides. However compared to adipic acid, pimelic acid is relatively small in importance industrially. Derivatives of pimelic acid are involved in the biosynthesis of the amino acid lysine and the vitamin biotin.
trans-Glutaconic acid is an organic compound with formula HO2CCH=CHCH2CO2H. This dicarboxylic acid exists as a colorless solid and is related to the saturated chemical glutaric acid, HO2CC(CH2)3CO2H. Esters and salts of glutaconic acid are called glutaconates.
Ricinoleic acid, formally called 12-hydroxy-9-cis-octadecenoic acid is a fatty acid. It is an unsaturated omega-9 fatty acid and a hydroxy acid. It is a major component of the seed oil obtained from castor plant seeds and is also found in the sclerotium of ergot. About 90% of the fatty acid content in castor oil is the triglyceride formed from ricinoleic acid.
Tartronic acid or 2-hydroxymalonic acid is an organic compound with the structural formula of HOHC(CO2H)2. This dicarboxylic acid is related to malonic acid. It is a white solid. It is produced by oxidation of glycerol:
α-Ketobutyric acid is an organic compound with the formula CH3CH2C(O)CO2H. It is a colorless solid that melts just above room temperature. Its conjugate base α-ketobutyrate is the predominant form found in nature (near neutral pH). It results from the lysis of cystathionine. It is also one of the degradation products of threonine, produced by the catabolism of the amino acid by threonine dehydratase. It is also produced by the degradation of homocysteine and the metabolism of methionine.
The molecular formula C3H4O4 (molar mass: 104.06 g/mol) may refer to:
Acetylenedicarboxylic acid or butynedioic acid is an organic compound (a dicarboxylic acid) with the formula C4H2O4 or HO2CC≡CCO2H. It is a crystalline solid that is soluble in diethyl ether.
Cycloheptanone, (CH2)6CO, is a cyclic ketone also referred to as suberone. It is a colourless volatile liquid. Cycloheptanone is used as a precursor for the synthesis of pharmaceuticals.
2-Methylsuccinic acid is an organic compound with the formula HO2CCH(CH3)CH2CO2H. A white solid, it is the simplest chiral dicarboxylic acid. It is a recurring component of urban aerosols. Salts and esters of 2-methylsuccinic acid are called 2-methylsuccinates.
Tartronic acid semialdehyde is the organic compound with the formula OCHCH(OH)CO2H. The molecule has three functional groups, aldehyde, alcohol, and carboxylic acid. A white solid, it occurs naturally. A near neutral pH, it exists as the hydrated carboxylate (HO)2CHCH(OH)CO2−, which is referred to as tartronate semialdehyde. Tartronate semialdehyde is produced and consumed on a prodigious scale as an intermediate in photorespiration, an undesirable side reaction that competes with photosynthesis. It is produced biologically by the condensation of two equivalents of glyoxalate: