Palmitoyl-L-carnitine-d₃is intended for use as an internal standard for the quantification of palmitoyl-L-carnitine by GC- or LC-MS. Palmitoyl-L-carnitine is a naturally occurring long-chain acylcarnitine and the L-enantiomer of palmitoyl-DL-carnitine .¹In cells, palmitoyl-L-carnitine is transported into mitochondriaviacarnitine palmitoyl transferase II to deliver palmitate for fatty acid oxidation and energy production.²It also inhibits lecithin:cholesterol acyltransferase activity in rat, but not human, plasma when used at a concentration of 500 ?M.³In vivo, palmitoyl-L-carnitine increases intestinal absorption of the antibiotic cefoxitin in rat intestine.⁴

1.Bezaire, V., Bruce, C.R., Heigenhauser, G.J.F., et al.Identification of fatty acid translocase on human skeletal muscle mitochondrial membranes: Essential role in fatty acid oxidationAm. J. Physiol. Endocrinol. Metab.290(3)E509-E515(2006) 2.El-Hayek, R., Valdivia, C., Valdivia, H.H., et al.Activation of the Ca2+ release channel of skeletal muscle sarcoplasmic reticulum by palmitoyl carnitineBiophys. J.65(2)779-789(1993) 3.Bell, F.P.Carnitine esters: Novel inhibitors of plasma lecithin: Cholesterol acyltransferase in experimental animals but not in man (Homo sapiens)Int. J. Biochem.15(2)133-136(1983) 4.Sutton, S.C., LeCluyse, E.L., Cammack, L., et al.Enhanced bioavailability of cefoxitin using palmitoyl L-carnitine. I. Enhancer activity in different intestinal regionsPharm. Res.9(2)191-194(1992)