Malondialdehyde

Malondialdehyde
IUPAC name propanedial
Identifiers
CAS number	542-78-9
PubChem	10964
KEGG	C19440 Y
Jmol-3D images	Image 1
SMILES C(C=O)C=O
Properties
Molecular formula	C3H4O2
Molar mass	72.0636 g/mol
Melting point	72 °C, 345 K, 162 °F
Related compounds
Related alkenals	Glucic acid 4-Hydroxynonenal
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

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.

Structure and synthesis

Malondialdehyde mainly exists in the enol form:^[1]

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.^[1] It is easily deprotonated to give the sodium salt of the enolate (m.p. 245 °C).

Biochemistry

Reactive oxygen species degrade polyunsaturated lipids, forming malondialdehyde.^[2] 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).^[3] The production of this aldehyde is used as a biomarker to measure the level of oxidative stress in an organism.^[4][5]

Malondialdehyde reacts with deoxyadenosine and deoxyguanosine in DNA, forming DNA adducts, the primary one being M₁G, which is mutagenic.^[6] The guanidine group of arginine residues condense with MDA to give 2-aminopyrimidines.

Human ALDH1A1 aldehyde dehydrogenase is capable of oxidising malondialdehyde.

Analysis

MDA and other "thiobarbituric reactive substances" (TBARS) condense with two equivalents of thiobarbituric acid to give a fluorescent red derivative that can be assayed spectrophotometrically.^[1][7] 1-Methyl-2-phenylindole is an alternative more selective reagent.^[1]

Hazards

MDA is reactive and potentially mutagenic.

Pathology

Corneas of patients suffering from keratoconus and bullous keratopathy have increased levels of MDA, according to one study.^[8] MDA also can be found in tissue sections of joints from patients with osteoarthritis.^[9]

See also

• Methylglyoxal
• 4-Hydroxynonenal

References

1. ^ ^{a b c d} V. Nair, C. L. O'Neil, P. G. Wang “Malondialdehyde” Encyclopedia of Reagents for Organic Synthesis, 2008, John Wiley & Sons, New York. doi:10.1002/047084289X.rm013.pub2 Article Online Posting Date: March 14, 2008
2. ^ Pryor WA, Stanley JP (1975). "Letter: A suggested mechanism for the production of malondialdehyde during the autoxidation of polyunsaturated fatty acids. Nonenzymatic production of prostaglandin endoperoxides during autoxidation". J. Org. Chem. 40 (24): 3615–7. doi:10.1021/jo00912a038. PMID 1185332. 
3. ^ Farmer EE, Davoine C (2007). "Reactive electrophile species". Curr. Opin. Plant Biol. 10 (4): 380–6. doi:10.1016/j.pbi.2007.04.019. PMID 17646124. 
4. ^ Moore K, Roberts LJ (1998). "Measurement of lipid peroxidation". Free Radic. Res. 28 (6): 659–71. doi:10.3109/10715769809065821. PMID 9736317. 
5. ^ Del Rio D, Stewart AJ, Pellegrini N (2005). "A review of recent studies on malondialdehyde as toxic molecule and biological marker of oxidative stress". Nutr Metab Cardiovasc Dis 15 (4): 316–28. doi:10.1016/j.numecd.2005.05.003. PMID 16054557. 
6. ^ Marnett LJ (1999). "Lipid peroxidation-DNA damage by malondialdehyde". Mutat. Res. 424 (1-2): 83–95. doi:10.1016/S0027-5107(99)00010-X. PMID 10064852. 
7. ^ http://www.amdcc.org/shared/showFile.aspx?doctypeid=3&docid=33
8. ^ Buddi R, Lin B, Atilano SR, Zorapapel NC, Kenney MC, Brown DJ (March 2002). "Evidence of oxidative stress in human corneal diseases". J. Histochem. Cytochem. 50 (3): 341–51. PMID 11850437. http://www.jhc.org/cgi/pmidlookup?view=long&pmid=11850437. 
9. ^ Tiku ML, Narla H, Jain M, Yalamanchili P (2007). "Glucosamine prevents in vitro collagen degradation in chondrocytes by inhibiting advanced lipoxidation reactions and protein oxidation". Arthritis Res. Ther. 9 (4): R76. doi:10.1186/ar2274. PMC 2206377. PMID 17686167. http://arthritis-research.com/content/9/4/R76.