The long-chain fatty acid amides are an emerging family of bioactive lipids with members that include N-acyl amino acids, primary fatty acid amides (PFAMs), N-acylarylalkylamides, N-acylethanolamines, and N-monoacylpolyamines. Fatty acid amides were first identified from biological sources over 50 years ago with the isolation and identification of N-palmitoylethanolamine from egg yolk in 1957 (1) and, in 1965, N-palmitoylethanolamine and N-stearoylethanolamine in several tissues from rat and guinea pig (2). The discovery of N-arachidonoylethanolamine (anandamide) as the endogenous ligand for the mammalian brain cannabinoid receptor CB 1 sparked a dramatic interest in the fatty acid amides (3). Since these early discoveries, a diversity of long-chain fatty acid amides have been identified in mammals and, more recently, in invertebrates as well (4)(5)(6)(7)(8).The N-fatty acylglycines, a subclass of the N-fatty acyl amino acids, are an important class of cell signaling lipids that are distributed throughout the central nervous system and the rest of the body (6, 7, 9). Identification of glycine conjugates dates back to the 1820s with the identification of N-benzoylglycine (hippurate) as a mammalian metabolite (10). N-arachidonoylglycine was the first longchain N-acylglycine identified from a mammalian source and was determined to have anti-nociceptive and antiinflammatory effects in rat models of pain (11). Since