|(hydrate: 1186-47-6) 78-98-8 (hydrate: 1186-47-6)|
|Jmol 3D model||Interactive image|
|Molar mass||72.06 g·mol−1|
|Boiling point||72 °C (162 °F; 345 K)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
Methylglyoxal, also called pyruvaldehyde or 2-oxopropanal, is the organic compound with the formula CH3C(O)CHO. Gaseous methylglyoxal has two carbonyl groups, an aldehyde and a ketone but in the presence of water, it exists as hydrates and oligomers. It is a reduced derivative of pyruvic acid.
Industrial production and use
In organisms, methylglyoxal is formed as a side-product of several metabolic pathways. It may form from 3-aminoacetone, which is an intermediate of threonine catabolism, as well as through lipid peroxidation. However, the most important source is glycolysis. Here, methylglyoxal arises from nonenzymatic phosphate elimination from glyceraldehyde phosphate and dihydroxyacetone phosphate, two intermediates of glycolysis. Since methylglyoxal is highly cytotoxic, the body developed several detoxification mechanisms. One of these is the glyoxalase system. Methylglyoxal reacts with glutathione to form a hemithioacetal. This is converted into S-D-lactoyl-glutathione by glyoxalase I, and then further metabolized into D-lactate by glyoxalase II.
The proximate and ultimate causes for biological methylglyoxal production remain unknown, but it may be involved in the formation of advanced glycation endproducts (AGEs). In this process, methylglyoxal reacts with free amino groups of lysine and arginine and with thiol groups of cysteine forming AGEs. Recent research has identified heat shock protein 27 (Hsp27) as a specific target of posttranslational modification by methylglyoxal in human metastatic melanoma cells.
Recently, one mechanism of activity in humans of methylglyoxal has been identified. Methylglyoxal binds directly to the nerve endings and by that increases the chronic extremity soreness in diabetic neuropathy.
Other glycation agents include the reducing sugars:
- glucose, the sugar that stores energy
- galactose, a component of milk sugar (lactose)
- allose, an all-cis hexose carried into the cell by special proteins
- ribose, a component of RNA.
Due to increased blood glucose levels, methylglyoxal has higher concentrations in diabetics and has been linked to arterial atherogenesis. Damage by methylglyoxal to low-density lipoprotein through glycation causes a fourfold increase of atherogenesis in diabetics.
Although methylglyoxal has been shown to increase carboxymethyllysine levels, methylglyoxal has been suggested to be a better marker for investigating the association between AGEs with adverse health outcomes.
Methylglyoxal is an active component of manuka honey. However, after neutralization of this compound, manuka honey retains bactericidal activity. Methylglyoxal thus does not appear to be the main contributor to the antimicrobial and antibacterial activities.
- Loeffler, Kirsten W.; Koehler, Charles A.; Paul, Nichole M.; De Haan, David O. "Oligomer Formation in Evaporating Aqueous Glyoxal and Methyl Glyoxal Solutions" Environmental Science & Technology 2006, volume 40, pp. 6318-6323. doi:10.1021/es060810w
- Frieder W. Lichtenthaler "Carbohydrates as Organic Raw Materials" in Ullmann's Encyclopedia of Industrial Chemistry 2010, Wiley-VCH, Weinheim. doi: 10.1002/14356007.n05_n07
- Inoue Y, Kimura A (1995). "Methylglyoxal and regulation of its metabolism in microorganisms". Adv. Microb. Physiol. Advances in Microbial Physiology 37: 177–227. doi:10.1016/S0065-2911(08)60146-0. ISBN 978-0-12-027737-7. PMID 8540421.
- Thornalley PJ (2003). "Glyoxalase I—structure, function and a critical role in the enzymatic defence against glycation". Biochem. Soc. Trans. 31 (Pt 6): 1343–8. doi:10.1042/BST0311343. PMID 14641060.
- Vander Jagt DL (1993). "Glyoxalase II: molecular characteristics, kinetics and mechanism". Biochem. Soc. Trans. 21 (2): 522–7. PMID 8359524.
- Shinohara M; Thornalley, PJ; Giardino, I; Beisswenger, P; Thorpe, SR; Onorato, J; Brownlee, M (1998). "Overexpression of glyoxalase-I in bovine endothelial cells inhibits intracellular advanced glycation endproduct formation and prevents hyperglycemia-induced increases in macromolecular endocytosis". J Clin Invest. 101 (5): 1142–7. doi:10.1172/JCI119885. PMC 508666. PMID 9486985.
- Bair WB 3rd, Cabello CM, Uchida K, Bause AS, Wondrak GT (April 2010). "GLO1 overexpression in human malignant melanoma". Melanoma Res 20 (2): 85–96. doi:10.1097/CMR.0b013e3283364903. PMC 2891514. PMID 20093988.
- Spektrum: Diabetische Neuropathie: Methylglyoxal verstärkt den Schmerz: DAZ.online. Deutsche-apotheker-zeitung.de (2012-05-21). Retrieved on 2012-06-11.
- Bierhaus, Angelika; Fleming, Thomas; Stoyanov, Stoyan; Leffler, Andreas; Babes, Alexandru; Neacsu, Cristian; Sauer, Susanne K; Eberhardt, Mirjam; et al. (2012). "Methylglyoxal modification of Nav1.8 facilitates nociceptive neuron firing and causes hyperalgesia in diabetic neuropathy". Nature Medicine 18 (6): 926–33. doi:10.1038/nm.2750. PMID 22581285.
- Rabbani N; Godfrey, L; Xue, M; Shaheen, F; Geoffrion, M; Milne, R; Thornalley, PJ (May 26, 2011). "Glycation of LDL by methylglyoxal increases arterial atherogenicity. A possible contributor to increased risk of cardiovascular disease in diabetes". Diabetes 60 (7): 1973–80. doi:10.2337/db11-0085. PMC 3121424. PMID 21617182.
- Cai, W., Uribarri, J., Zhu, L., Chen, X., Swamy, S., Zhao, Z., Grosjean, F., Simonaro, C., Kuchel, G. A., Schnaider-Beeri, M., Woodward, M., Striker, G. E., and Vlassara, H. (2014) Oral glycotoxins are a modifiable cause of dementia and the metabolic syndrome in mice and humans. PNAS 111.
- Kwakman PHS; te Velde AA; de Boer L; Vandenbroucke-Grauls CMJE; Zaat SAJ (2011). "Two major medicinal honeys have different mechanisms of bactericidal activity". PLoS ONE 6 (3): e17709. doi:10.1371/journal.pone.0017709. PMC 3048876. PMID 21394213.
- Molan, P. (2008). "An explanation of why the MGO level in manuka honey does not show the antibacterial activity". New Zealand BeeKeeper 16 (4): 11–13.