What does acylation mean?
Acylation is a fundamental process in chemistry in which an acyl group — a fragment of the form RCO–, derived from a carboxylic acid — is introduced into another molecule, usually by replacing a hydrogen atom attached to oxygen, nitrogen, carbon, or sulfur. The result is typically an ester, amide, ketone, or related compound. Chemists rely on acylation constantly in synthesis: the classic Friedel–Crafts acylation attaches acyl groups to aromatic rings, while treating amines with acetic anhydride produces amides. In biochemistry, the same principle operates inside living cells, where acylation of proteins — for example, the addition of fatty-acyl chains — controls how they fold, localize, and interact with membranes. The reverse process, removal of an acyl group, is called deacylation. The word derives from 'acyl', itself rooted in the Latin acidus, meaning sour or acid. Though confined largely to scientific writing, acylation underpins everyday products from aspirin to nylon, making it one of the quiet workhorses of modern chemistry.
nounThe chemical process of introducing an acyl group into a compound, typically by replacing a hydrogen atom with an acyl radical such as RCO–.
- In organic chemistry: the introduction of an acyl group (RCO–) into a compound, replacing a hydrogen atom, typically on oxygen, nitrogen, carbon, or sulfur.
- More broadly in biochemistry: the attachment of acyl groups (such as acetyl or fatty-acyl groups) to proteins or other biomolecules, modifying their function.
"The Friedel–Crafts acylation of benzene introduces an acyl group onto the aromatic ring using an acid chloride and aluminium chloride."
"The synthesis proceeds by acylation of the amine with acetic anhydride to form the amide."
"Post-translational acylation of the protein altered its ability to anchor to the cell membrane."
Used when referring to multiple distinct acylation reactions or instances, especially in experimental or review contexts.
"Both acylations were carried out under nitrogen to prevent hydrolysis of the acid chlorides."
Without acylation, aspirin as we know it wouldn't exist — the drug works because an acetyl group is tacked onto salicylic acid.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of acylation
Acylation is formed from 'acyl', a term coined in German (Acyl) in the late 19th century by combining 'acid' with the suffix '-yl' used for chemical radicals, combined with '-ation', the standard English noun-forming suffix from Latin. The ultimate root is the Latin acidus, meaning sour, which also gives us 'acid' and 'acidic'. As a technical coinage of modern chemistry rather than an inherited word, it has no ancient cognates beyond those sharing the acid root.
Related word forms
How acylation is actually used
Strictly technical vocabulary used almost exclusively in chemistry and biochemistry contexts; it would sound out of place in general conversation. In biochemical usage, 'acylation' often refers specifically to lipid or protein modification, while in synthetic organic chemistry it usually denotes a named reaction type such as Friedel–Crafts acylation.
Easily confused with acylation
Alkylation adds an alkyl group to a molecule, whereas acylation adds an acyl group (RCO–), which contains a carbonyl.