The preparation of 2-O-[1′-14C]arachidonoyl-1-O-stearoyl-sn-glycerol

2-O-Arachidonoyl-1-O-stearoyl-sn-glycerol is the most abundant molecular species of the 1,2-diacyl-sn-glycerol signaling lipids in neural tissue. The facile preparation of 2-O-[1'-C-14]arachidonoyl-1-O-stearoyl-sn-glycerol from 2-O-[1'-C-14]arachidonoyl-1-O-stearoyl-sn-glycero-3-phosphocholine at a hexane and phosphate buffer interface with phospholipase C was demonstrated on a 20 mu Ci scale in 83% radiochemical yield. The specific activity of the product 2-O-[1'-C-14]arachidonoyl-1-O-stearoyl-sn-glycerol was 57.0 mCi/mmol and the radiochemical purity was determined to be > 99% by TLC. The hydrolysis of this lipid biosynthetic intermediate with lipoprotein lipase was shown to produce 2-O-[1'-C-14]arachidonoylglycerol (2-AG). The C-14-radiolabeled monoacylglycerol 2-AG is an endogenous cannabinoid receptor-signaling molecule (endocannabinoid).