Linoleoyl Ethanolamide-d4 (Synonyms: LEA-d4)

Linoleoyl ethanolamide-d₄ contains four deuterium atoms at the hydroxyethyl 1,1',2, and 2' positions. It is intended for use as an internal standard for the quantification of linoleoyl ethanolamide by GC- or LC-mass spectrometry. Linoleoyl ethanolamide is an endocannabinoid detected in porcine brain and murine peritoneal macrophages which contains linoleate in place of the arachidonate moiety of arachidonoyl ethanolamide (AEA).^1,2 It has weak affinity for the central cannabinoid (CB₁) and peripheral cannabinoid (CB₂) receptors, exhibiting K_i values of 10 µM and 25 µM, respectively.³ However, it is only approximately 4-fold less potent than AEA at causing catalepsy in mice (ED₅₀ of 26.5 mg/kg).⁴ In addition, linoleoyl ethanolamide increases ERK phosphorylation and AP-1-dependent transcription approximately 1.5-fold at 15 µM in a CB-receptor-independent manner.⁵ However, cellular toxicity is readily apparent at concentrations of 10-20 µM. Linoleoyl ethanolamide inhibits human fatty acid amide hydrolase-dependent hydrolysis of AEA with a K_i value of 9.0 µM, but also is hydrolyzed effectively by the enzyme.^6,7

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