Carnitine facilitates the transport of fatty acids into the mitochondria to be used in fatty acid metabolism. It does so by accepting acyl groups from fatty acids complexed with coenzyme A, which yields esterified carnitine or acylcarnitines that enable the transport of fatty acyl groups into the inner mitochondrial matrix. β-Oxidation of fatty acids in mitochondria is inhibited by uncoupling conditions, thus changes in circulating levels of various acylcarnitines have been used to identify alterations in metabolic state.[1] [2] Arachidonoyl-L-carnitine formed from carnitine conjugated to arachidonic acid .
Several different arachidonoyl amino acids, including N-arachidonoyl-L-alanine (NALA), have been isolated and characterized from bovine brain. The glycine congener (NAGly) was further characterized and found to suppress formalin-induced pain in rats. NALA may have activity at cannabinoid receptor and/or VR1, but has not been fully characterized to date.
Linoleoyl-L-carnitine is a naturally occurring long-chain acylcarnitine. Hepatic levels of linoleoyl-L-carnitine are increased following high-dose (200 mg kg) administration of isoniazid in mice.
Isobutyryl-L-carnitine is a member of the class of compounds known as acylcarnitines. Isobutyryl-L-carnitine is a product of the acyl-CoA dehydrogenases.
Carnitine is a quaternary amine that occurs naturally in most mammalian tissue. Carnitine is present in relatively high concentrations in skeletal muscle and heart where it is involved in regulating energy metabolism. It has also been used to allow the en
Palmitoyl-D-carnitine is a long-chain acylcarnitine, an isomer of palmitoyl-L-carnitine , and the D enantiomer of palmitoyl-DL-carnitine . It inhibits carnitine palmitoyltransferase with a Ki value of 2.1 mM for 14C-palmitoylcarnitine synthesis by erythrocyte membranes.
Hexanoyl-L-carnitine is a medium-chain acylcarnitine. It has been used in the synthesis of acylcarnitine benzyl esters.1 1.Gong, X.-w., Li, J.-p., Wu, J.-f., et al.Synthesis of carnitine benzyl esters as prodrugsJ. Chem. Res.2008(6)327-330(2008)
Decanoyl-L-carnitine is an ester derivative of L-carnitine . It increases the formation of C24 fatty acid intermediates, as well as docosapentaenoic and docosahexaenoic acid in rat hepatocytes.
Valeryl-L-carnitine is a short-chain acylcarnitine and a derivative of L-carnitine . Valeryl-L-carnitine levels increase in the serum of rhesus monkeys following exposure to 7 and 10 Gray units (Gy) of ionizing radiation.[1]
N-Arachidonoyl-L-serine (ARA-S), a recently isolated endocannabinoid with a distinct activity profile that diverges from typical endocannabinoids, does not interact with central cannabinoid (CB1), peripheral cannabinoid (CB2) receptors, or vanilloid receptor 1 (VR1). Unlike other compounds, ARA-S (5 mg kg) counteracts the lowering of blood pressure induced by a 10 mg kg intravenous bolus of abnormal cannabidiol (Abn-CBD) in anesthetized rat models. Additionally, akin to Abn-CBD, ARA-S induces relaxation in isolated rat mesenteric arteries and abdominal aorta and promotes phosphorylation of Akt and mitogen-activated protein kinase (MAPK) in human umbilical vein endothelial cells (HUVEC). The mechanisms through which ARA-S and Abn-CBD exert their effects on vascular systems show variations and merit deeper investigation.
[(3R)-3-Hydroxydodecanoyl]-L-carnitine is an endogenous metabolite[1]. [1]. Hunter WG, et al. Metabolomic Profiling Identifies Novel Circulating Biomarkers of Mitochondrial Dysfunction Differentially Elevated in Heart Failure With Preserved Versus Reduced Ejection Fraction: Evidence for Shared Metabolic Impairments in Clinical Heart Failure. J Am Heart Assoc. 2016;5(8):e003190. Published 2016 Jul 29.
trans-2-Hexadecenoyl-L-carnitine is an endogenous metabolite in urine[1]. [1]. Pengxiang She, et al. Leucine and protein metabolism in obese Zucker rats. PLoS One. 2013;8(3):e59443.
trans-2-Octenoyl-L-carnitine is a synthetic carnitine.1It has been used as a standard for the detection of carnitines in human urine. 1.Yang, S., Minkler, P., and Hoppel, C.cis-3,4-methylene-heptanoylcarnitine: Characterization and verification of the C8:1 acylcarnitine in human urineJ. Chromatogr. B. Analyt. Technol. Biomed. Life Sci.857(2)251-258(2007)
Isovaleryl-L-carnitine is a naturally occurring acylcarnitine that is formed via metabolic conversion of L-leucine. It increases survival and decreases apoptosis in hepatocyte growth factor-deprived murine C2.8 hepatocytes when used at a concentration of 1 mM. Isovaleryl-L-carnitine inhibits amino acid deprivation-induced proteolysis and autophagy in isolated perfused rat liver when used at concentrations of 77 and 100 μM, respectively. Increased levels of isovaleryl carnitine are associated with isovaleryl-CoA dehydrogenase deficiency (isovaleric acidemia).
Butyryl-L-carnitine is a butyrate ester of carnitine. It is an inhibitor of intestinal transporters, blocking carnitine uptake by the carnitine transporter and glycine transport by the amino acid transporter in human retinal pigment epithelial (HRPE) cells (IC50s = 1.5 μM and 4.6 mM, respectively).