Maleimide
Encyclopedia
Maleimide is the chemical compound
with the formula
H2C2(CO)2NH (see diagram). This unsaturated imide
is an important building block in organic synthesis
. The name is a contraction of maleic acid
and imide
, the -C(O)NHC(O)- functional group
. Maleimides also describes a class of derivatives of the parent maleimide where the NH group is replaced with alkyl or aryl
groups such as a methyl or phenyl, respectively. The substituent can also be a polymer
such as polyethylene glycol
. Human hemoglobin
chemically modified with maleimide-polyethylene glycol is a blood substitute
called MP4.
by treatment with amine
s followed by dehydration. A special feature of the reactivity of maleimides is their susceptibility to additions across the double bond either by Michael additions or via Diels-Alder reactions. Bismaleimides are a class of compounds with two maleimide groups connected through a molecular unit and used as crosslinking reagents in polymer chemistry.
was first isolated in 2009 from the entomopathogenic fungus
Isaria farinosa (Paecilomyces farinosus) - source H599 (Japan).
chains are often used as flexible linking molecules to attach proteins to surfaces. The double bond readily reacts with the thiol
group found on cysteine
to form a stable carbon-sulfur bond. Attaching the other end of the polyethylene chain to a bead or solid support allows for easy separation of protein from other molecules in solution, provided these molecules do not also possess thiol groups.
chains are often used as flexible linking molecules to reinforce the rubber (tire
). The double bond readily reacts with all hydroxy
, amine
or thiol
groups found on the matrix to form a stable carbon-sulfur, carbon-nitrogen or carbon-carbon bond.
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
with the formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
H2C2(CO)2NH (see diagram). This unsaturated imide
Imide
In organic chemistry, an imide is a functional group consisting of two carbonyl groups bound to nitrogen. These compounds are structurally related to acid anhydrides. The relationship between esters and amides and between imides and anhydrides is analogous, the amine-derived groups are less reactive...
is an important building block in organic synthesis
Organic synthesis
Organic synthesis is a special branch of chemical synthesis and is concerned with the construction of organic compounds via organic reactions. Organic molecules can often contain a higher level of complexity compared to purely inorganic compounds, so the synthesis of organic compounds has...
. The name is a contraction of maleic acid
Maleic acid
Maleic acid is an organic compound that is a dicarboxylic acid, a molecule with two carboxyl groups. Maleic acid is the cis-isomer of butenedioic acid, whereas fumaric acid is the trans-isomer...
and imide
Imide
In organic chemistry, an imide is a functional group consisting of two carbonyl groups bound to nitrogen. These compounds are structurally related to acid anhydrides. The relationship between esters and amides and between imides and anhydrides is analogous, the amine-derived groups are less reactive...
, the -C(O)NHC(O)- functional group
Functional group
In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. The same functional group will undergo the same or similar chemical reaction regardless of the size of the molecule it is a part of...
. Maleimides also describes a class of derivatives of the parent maleimide where the NH group is replaced with alkyl or aryl
Aryl
In the context of organic molecules, aryl refers to any functional group or substituent derived from an aromatic ring, be it phenyl, naphthyl, thienyl, indolyl, etc....
groups such as a methyl or phenyl, respectively. The substituent can also be a polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
such as polyethylene glycol
Polyethylene glycol
Polyethylene glycol is a polyether compound with many applications from industrial manufacturing to medicine. It has also been known as polyethylene oxide or polyoxyethylene , depending on its molecular weight, and under the tradename Carbowax.-Available forms:PEG, PEO, or POE refers to an...
. Human hemoglobin
Hemoglobin
Hemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates, with the exception of the fish family Channichthyidae, as well as the tissues of some invertebrates...
chemically modified with maleimide-polyethylene glycol is a blood substitute
Blood substitute
A blood substitute is a substance used to mimic and fulfill some functions of biological blood, usually in the oxygen-carrying sense...
called MP4.
Organic chemistry
Maleimide and its derivatives are prepared from maleic anhydrideMaleic anhydride
Maleic anhydride is an organic compound with the formula C2H22O. It is the acid anhydride of maleic acid and in its pure state it is a colourless or white solid with an acrid odour....
by treatment with amine
Amine
Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...
s followed by dehydration. A special feature of the reactivity of maleimides is their susceptibility to additions across the double bond either by Michael additions or via Diels-Alder reactions. Bismaleimides are a class of compounds with two maleimide groups connected through a molecular unit and used as crosslinking reagents in polymer chemistry.
Natural Maleimides
Only a handful of natural maleimides - exemplified by the cytotoxic showdomycin from Streptomyces showdoensis., and pencolide from Pe. multicolor - have been reported. FarinomaleinFarinomalein
Farinomalein - a natural maleimide with formula C10H13NO4 - was first isolated from the entomopathogenic fungus Isaria farinosa - source H599 ....
was first isolated in 2009 from the entomopathogenic fungus
Entomopathogenic fungus
An entomopathogenic fungus is a fungus that can act as a parasite of insects and kills or seriously disables them.-Typical life cycle:These fungi usually attach to the external body surface of insects in the form of microscopic spores...
Isaria farinosa (Paecilomyces farinosus) - source H599 (Japan).
Biotechnology applications
Maleimides linked to polyethylene glycolPolyethylene glycol
Polyethylene glycol is a polyether compound with many applications from industrial manufacturing to medicine. It has also been known as polyethylene oxide or polyoxyethylene , depending on its molecular weight, and under the tradename Carbowax.-Available forms:PEG, PEO, or POE refers to an...
chains are often used as flexible linking molecules to attach proteins to surfaces. The double bond readily reacts with the thiol
Thiol
In organic chemistry, a thiol is an organosulfur compound that contains a carbon-bonded sulfhydryl group...
group found on cysteine
Cysteine
Cysteine is an α-amino acid with the chemical formula HO2CCHCH2SH. It is a non-essential amino acid, which means that it is biosynthesized in humans. Its codons are UGU and UGC. The side chain on cysteine is thiol, which is polar and thus cysteine is usually classified as a hydrophilic amino acid...
to form a stable carbon-sulfur bond. Attaching the other end of the polyethylene chain to a bead or solid support allows for easy separation of protein from other molecules in solution, provided these molecules do not also possess thiol groups.
Technological applications
Mono- and bismaleimide-based polymers are used for high temperature applications up to 250°C. Maleimides linked to rubberRubber
Natural rubber, also called India rubber or caoutchouc, is an elastomer that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined...
chains are often used as flexible linking molecules to reinforce the rubber (tire
Tire
A tire or tyre is a ring-shaped covering that fits around a wheel rim to protect it and enable better vehicle performance by providing a flexible cushion that absorbs shock while keeping the wheel in close contact with the ground...
). The double bond readily reacts with all hydroxy
Hydroxyl
A hydroxyl is a chemical group containing an oxygen atom covalently bonded with a hydrogen atom. In inorganic chemistry, the hydroxyl group is known as the hydroxide ion, and scientists and reference works generally use these different terms though they refer to the same chemical structure in...
, amine
Amine
Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...
or thiol
Thiol
In organic chemistry, a thiol is an organosulfur compound that contains a carbon-bonded sulfhydryl group...
groups found on the matrix to form a stable carbon-sulfur, carbon-nitrogen or carbon-carbon bond.
External links
- The MP4 website, Molecule of the Month, December 2004