Acylcholines are acyl chain esterified to choline. Acetylcholine acts as a neurotransmitter in the central and peripheral nervous systems as well as an inhibitor of cytokine production by macrophages and immune cells. Acylcholines are metabolized by cholinesterases acetylcholinesterase (ACHE) and butyrylcholinesterase (BCHE). Long-chain acylcholines show greater stability in circulation. Metabolomic profiling studies have expanded endogenously produced members of the acylcholine class to include long-chain esters. This entry also contains phosphatidylcholine (phospholipids that incorporate choline as a headgroup) major component of biological membranes