Nacetyl

N-acetyl is a chemical prefix used to denote an acetyl group (CH3-CO-) attached to a nitrogen atom in a molecule. When the acetyl group bonds to nitrogen, the result is typically an amide, and the parent compound is called an N-acetyl derivative. In organic synthesis, N-acetylation is performed to modify amines, protect reactive amine groups, or prepare acetamide derivatives. Common reagents for N-acetylation include acetic anhydride and acetyl chloride; reaction conditions and protecting-group strategies govern selectivity and deprotection.

In biology and biochemistry, N-acetylation is widespread and functionally important. N-terminal acetylation of proteins is a common post-translational modification in eukaryotes, carried out by N-terminal acetyltransferases and influencing protein stability, localization, and interactions. The N-acetyl group also appears in many biomolecules, such as N-acetylglucosamine (GlcNAc) units in chitin, peptidoglycan, and glycoproteins, and in N-acetylneuraminic acid (sialic acid) found on glycoproteins and glycolipids. N-acetyl groups can modulate charge, hydrophilicity, and recognition properties of molecules.

Notable examples commonly encountered include N-acetylcysteine (NAC), a water-soluble drug and antioxidant; N-acetylglucosamine, a monosaccharide derivative used as a dietary supplement; and N-acetyltransferase enzymes that catalyze the transfer of acetyl groups from acetyl-CoA to amino groups.

N-acetyl should be distinguished from acetylation at other sites (such as O-acetylation) and from simple acetyl groups not bound to nitrogen.