organic chemistry, acetyl (ethanoyl), is a functional group, the acylof acetic acid, with chemical formula-COCH3. It is sometimes abbreviated as Ac (not to be confused with the element actinium). The acetyl radical contains a methylgroup single-bonded to a carbonyl. The carbonof the carbonyl has a lone electronavailable, with which it forms a chemical bondto the remainder "R" of the molecule.
The acetyl radical is a component of many
organic compounds, including the neurotransmitter acetylcholine, and acetyl-CoA, and the analgesics acetaminophenand acetylsalicylic acid (better known as aspirin).
The introduction of an acetyl group into a molecule is called
acetylation(or ethanoylation). In biological organisms, acetyl groups are commonly transferred bound to Coenzyme A(CoA), in the form of acetyl-CoA. Acetyl-CoA is an important intermediate both in the biological synthesis and in the breakdown of many organic molecules.
Acetyl groups are also frequently added to
histones and other proteins modifying their properties. For example, on the DNA level, histone acetylation by acetyltransferases (HATs) causes an expansion of chromatin architecture allowing for genetic transcription to take place. Conversely, removal of the acetyl group by histone deacetylases (HDACs) condenses DNA structure, thereby preventing transcription. [cite journal |author=North B, Verdin E |title=Sirtuins: Sir2-related NAD-dependent protein deacetylases |journal=Genome Biol |volume=5 |issue=5 |pages=224 |year=2004 |pmid=15128440 | doi = 10.1186/gb-2004-5-5-224]
acetylationcan be achieved using a variety of methods, most commonly by the use of acetic anhydrideor acetyl chloridein the presence of a tertiary or aromatic aminebase.
When acetyl groups are bound to certain other organic molecules, they impart an increased ability to cross the
blood-brain barrier. This makes the drug reach the brain more quickly, making the drug's effects more intense and increasing the effectiveness of a given dose. Acetyl groups are used to make the natural anti-inflammatant salicylic acidinto the more effective acetylsalicylic acid, or aspirin. Similarly, they make the natural painkiller morphineinto diacetylmorphine, or heroin.
Most recently, the supplement industry touts
acetyl-L-carnitineas being more effective than other preparations of carnitine. Also, research on irradiated rodents shows resveratrolattached to acetyl as holding promise as one of the first anti-radiation medicines for human populations. For citation, see the webpage article of http://www.sciencedaily.com/releases/2008/09/080923181110.htm.
Histone acetylation and deacetylation
Polyoxymethylene plastic, a.k.a. acetal resin, a thermoplastic
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