2arachidonoyl

2-arachidonoyl is a shorthand used in lipid chemistry to denote an arachidoyl group, the acyl portion derived from arachidonic acid, attached at the second carbon (sn-2) of a glycerol backbone or other lipid moiety. This notation is commonly used to describe the structure of monoacylglycerols, diacylglycerols, and glycerophospholipids where the sn-2 position carries the arachidoyl chain.

Arachidonic acid is a polyunsaturated 20-carbon fatty acid with four cis double bonds (20:4, typically designated as ω-6). The sn-2 position in many phospholipids and related lipids is frequently occupied by arachidoyl, reflecting its role as a reservoir for signaling molecules in cell membranes. The presence of an arachidoyl group at sn-2 influences membrane properties and the substrate availability for enzymatic reactions.

Biological significance flows from the metabolism of 2-arachidonoyl-containing lipids. Phospholipase A2 enzymes cleave the sn-2 arachidonoyl bond to release free arachidonic acid, a precursor to eicosanoids such as prostaglandins and leukotrienes. In another context, 2-arachidonoyl glycerol (2-AG) is a prominent endocannabinoid that acts as a signaling lipid by activating cannabinoid receptors CB1 and CB2. 2-AG is formed in cells from diacylglycerol by DAG lipase and participates in neuromodulatory processes and other physiological functions.

Overall, 2-arachidonoyl denotes the structural placement of arachidonic acid at the sn-2 position, with important implications for lipid signaling and metabolism.