Malondialdehyde
Encyclopedia
Malondialdehyde is the organic compound
with the formula
CH2(CHO)2. The structure of this species is more complex than this formula suggests. This reactive species occurs naturally and is a marker for oxidative stress
.
form:
In organic solvents, the cis isomer is favored, whereas in water the trans isomer predominates.
Malondialdehyde is a highly reactive compound that is not typically observed in pure form. In the laboratory it can be generated in situ by hydrolysis of 1,1,3,3-tetramethoxypropane, which is commercially available. It is easily deprotonated to give the sodium salt of the enolate (m.p. 245 °C).
degrade polyunsaturated lipids
, forming malondialdehyde. This compound is a reactive aldehyde
and is one of the many reactive electrophile species that cause toxic stress in cells and form covalent protein adducts referred to as advanced lipoxidation end-products (ALE), in analogy to advanced glycation end-products (AGE). The production of this aldehyde is used as a biomarker to measure the level of oxidative stress
in an organism.
Malondialdehyde reacts with deoxyadenosine
and deoxyguanosine
in DNA, forming DNA adducts, the primary one being M1G
, which is mutagenic. The guanidine group of arginine residues condense with MDA to give 2-aminopyrimidines.
Human ALDH1A1
aldehyde dehydrogenase is capable of oxidising malondialdehyde.
to give a fluorescent red derivative that can be assayed spectrophotometrically. 1-Methyl-2-phenylindole is an alternative more selective reagent.
s of patients suffering from keratoconus
and bullous keratopathy
have increased levels of MDA, according to one study. MDA also can be found in tissue sections of joints from patients with osteoarthritis
.
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
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....
CH2(CHO)2. The structure of this species is more complex than this formula suggests. This reactive species occurs naturally and is a marker for oxidative stress
Oxidative stress
Oxidative stress represents an imbalance between the production and manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage...
.
Structure and synthesis
Malondialdehyde mainly exists in the enolEnol
Enols are alkenes with a hydroxyl group affixed to one of the carbon atoms composing the double bond. Alkenes with a hydroxyl group on both sides of the double bond are called enediols. Deprotonated anions of enols are called enolates...
form:
- CH2(CHO)2 → HOCH=CH-CHO
In organic solvents, the cis isomer is favored, whereas in water the trans isomer predominates.
Malondialdehyde is a highly reactive compound that is not typically observed in pure form. In the laboratory it can be generated in situ by hydrolysis of 1,1,3,3-tetramethoxypropane, which is commercially available. It is easily deprotonated to give the sodium salt of the enolate (m.p. 245 °C).
Biochemistry
Reactive oxygen speciesReactive oxygen species
Reactive oxygen species are chemically reactive molecules containing oxygen. Examples include oxygen ions and peroxides. Reactive oxygen species are highly reactive due to the presence of unpaired valence shell electrons....
degrade polyunsaturated lipids
Polyunsaturated fat
In nutrition, polyunsaturated fat, or polyunsaturated fatty acid, are fatty acids in which more than one carbon–carbon double bond exists within the representative molecule. That is, the molecule has two or more points on its structure capable of supporting hydrogen atoms not currently part of the...
, forming malondialdehyde. This compound is a reactive aldehyde
Aldehyde
An aldehyde is an organic compound containing a formyl group. This functional group, with the structure R-CHO, consists of a carbonyl center bonded to hydrogen and an R group....
and is one of the many reactive electrophile species that cause toxic stress in cells and form covalent protein adducts referred to as advanced lipoxidation end-products (ALE), in analogy to advanced glycation end-products (AGE). The production of this aldehyde is used as a biomarker to measure the level of oxidative stress
Oxidative stress
Oxidative stress represents an imbalance between the production and manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage...
in an organism.
Malondialdehyde reacts with deoxyadenosine
Deoxyadenosine
Deoxyadenosine is a deoxyribonucleoside. It is a derivative of the nucleoside adenosine, differing from the latter by the replacement of a hydroxyl group by hydrogen at the 2' position of its ribose sugar moiety. Deoxyadenosine is the DNA nucleoside A, which pairs with deoxythymidine in...
and deoxyguanosine
Deoxyguanosine
Deoxyguanosine is composed of the purine nucleoside guanine linked by its N9 nitrogen to the C1 carbon of deoxyribose. It is similar to guanosine, but with one hydroxyl group removed from the 2' position of the ribose sugar . If a phosphate group is attached at the 5' position, it becomes...
in DNA, forming DNA adducts, the primary one being M1G
M1G
M1G is a heterocyclic compound which is a by-product of base excision repair of a specific type of DNA adduct called M1dG. The M1dG adduct in turn is formed by a condensation reaction between guanosine nucleotides in DNA and either malondialdehyde or base propenal...
, which is mutagenic. The guanidine group of arginine residues condense with MDA to give 2-aminopyrimidines.
Human ALDH1A1
ALDH1A1
Aldehyde dehydrogenase 1 family, member A1 also known as ALDH1A1 is an enzyme that in humans is encoded by the ALDH1A1 gene.- Function :...
aldehyde dehydrogenase is capable of oxidising malondialdehyde.
Analysis
MDA and other "thiobarbituric reactive substances" (TBARS) condense with two equivalents of thiobarbituric acidThiobarbituric acid
Thiobarbituric acid is an organic compound and a heterocycle. It is used as a reagent in assaying malondialdehyde .TBARS are higher in people who have headaches...
to give a fluorescent red derivative that can be assayed spectrophotometrically. 1-Methyl-2-phenylindole is an alternative more selective reagent.
Pathology
CorneaCornea
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens, the cornea refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is...
s of patients suffering from keratoconus
Keratoconus
Keratoconus , is a degenerative disorder of the eye in which structural changes within the cornea cause it to thin and change to a more conical shape than its normal gradual curve....
and bullous keratopathy
Bullous keratopathy
Bullous keratopathy is a pathological condition in which small vesicles, or bullae, are formed in the cornea due to endothelial dysfunction....
have increased levels of MDA, according to one study. MDA also can be found in tissue sections of joints from patients with osteoarthritis
Osteoarthritis
Osteoarthritis also known as degenerative arthritis or degenerative joint disease, is a group of mechanical abnormalities involving degradation of joints, including articular cartilage and subchondral bone. Symptoms may include joint pain, tenderness, stiffness, locking, and sometimes an effusion...
.