organic chemistry Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, organic materials, i.e., matter in its various forms that contain ...

, a semialdehyde is a compound containing an

aldehyde In organic chemistry, an aldehyde () (lat. ''al''cohol ''dehyd''rogenatum, dehydrogenated alcohol) is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred ...

and a

carboxylic acid In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an Substituent, R-group. The general formula of a carboxylic acid is often written as or , sometimes as with R referring to an organyl ...

functional group In organic chemistry, a functional group is any substituent or moiety (chemistry), moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions r ...

s. Semialdehydes are common in

biochemistry Biochemistry, or biological chemistry, is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology, a ...

. The simplest semialdehydes have the formula . As illustrated by the behavior of the smallest member,

glyoxylic acid Glyoxylic acid or oxoacetic acid is an organic compound. Together with acetic acid, glycolic acid, and oxalic acid, glyoxylic acid is one of the C2 carboxylic acids. It is a colourless solid that occurs naturally and is useful industrially. Str ...

, semialdehydes often exist as hydrates (

geminal diol A geminal diol (or gem-diol for short) is any organic compound having two hydroxyl functional groups () bound to the same carbon atom. Geminal diols are a subclass of the diols, which in turn are a special class of alcohols. Most of the geminal ...

s) . Some of semialdehydes and their parent

dicarboxylic acid 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 , where R can be aliphatic or aromatic.Boy Cornils, Peter Lappe "Dicarbox ...

s are listed below. {, class="wikitable" , + Selected Semialdehydes and their parent diacid , - ! Semialdehyde!! Dicarboxylic acid , - ,

malonic semialdehyde 3-Oxopropanoic acid (also malonic semialdehyde or formylacetic acid) is an organic chemical compound that carries both a carboxylic acid function and an aldehyde function. Natural occurence In nature, 3-oxopropanoic acid occurs as a metabolic inte ...

malonic acid Malonic acid is a dicarboxylic acid with structure CH2(COOH)2. The ionized form of malonic acid, as well as its esters and salts, are known as malonates. For example, diethyl malonate is malonic acid's diethyl ester. The name originates from ...

, - , tartronic semialdehyde , tartronic acid , - ,

succinic semialdehyde Succinic semialdehyde (SSA) is a GABA and GHB metabolite. It is formed from GABA by the action of GABA transaminase (4-aminobutyrate aminotransferase) and further oxidised to become succinic acid, which enters TCA cycle. SSA is oxidized into suc ...

succinic acid 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 fum ...

, - , methylmalonic semialdehyde ,

methylmalonic acid Methylmalonic acid (MMA) is a chemical compound from the group of dicarboxylic acids. It consists of the basic structure of malonic acid and also carries a methyl group. The salts of methylmalonic acid are called methylmalonates. Metabolism Met ...

, - , aspartic-4-semialdehyde ,

aspartic acid Aspartic acid (symbol Asp or D; the ionic form is known as aspartate), is an α-amino acid that is used in the biosynthesis of proteins. The L-isomer of aspartic acid is one of the 22 proteinogenic amino acids, i.e., the building blocks of protei ...

, - , glutamic-1-semialdehyde ,

glutamic acid Glutamic acid (symbol Glu or E; known as glutamate in its anionic form) is an α- amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can ...

, - , glutamic-5-semialdehyde ,

, - , 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.

References

Aldehydic acids