1-Arachidonoyl Glycerol

The glyceryl esters of arachidonic acid have been proposed as endogenous cannabinoid ligands.{4614} 2-AG is 10 to 100 times more potent than 1-AG in ligand binding affinity and agonist activity at the CB1 receptor, and is thus considered to be the natural ligand.{5306} However, 2-AG is chemically unstable and undergoes rapid isomerization to 1-AG (synonymous with 1(3)-AG) both in vitro and in vivo. 1-AG is a frequent contaminant in synthetic 2-AG preparations, and can markedly reduce their cannabinergic potency. 1-AG is a weak CB1 receptor agonist and may have other pharmacologic properties.