L-Carnitine

L-Carnitine is a quaternary ammonium compound synthesized in mammals from lysine-derived trimethyllysine and best known as the carrier that moves activated fatty acids and acetyl groups across the inner mitochondrial membrane. Researchers have examined L-carnitine in studies of the carnitine palmitoyltransferase system, acetyl-CoA buffering by carnitine acetyltransferase in mouse muscle, and gut-microbial conversion of dietary L-carnitine to trimethylamine N-oxide in mice. Research Market supplies L-carnitine in 200 mg, 400 mg and 600 mg sizes, with lot data on the certificate of analysis. It is sold strictly for laboratory research use.

Chemical structure and identification

• Molecular formula: C₇H₁₅NO₃
• Molecular weight: 161.20 g/mol
• CAS number: 541-15-1
• PubChem CID: 10917
• Synonyms: levocarnitine, (−)-carnitine, vitamin BT
• Form: Supplied in a sealed research vial; sizes 200 mg, 400 mg and 600 mg
• Analytical methods: Identity and purity data reported on the batch certificate of analysis

Research applications

• Carnitine metabolism: Reviewed for its biosynthesis from lysine via trimethyllysine and butyrobetaine, its uptake by tissues and its function as a carrier of activated fatty acids and activated acetate across the inner mitochondrial membrane [1]
• Mitochondrial fatty acid import: Reviewed as part of the CPT-I, carnitine:acylcarnitine translocase and CPT-II transport system for long-chain fatty acids, including malonyl-CoA regulation of CPT-I [2]
• Acetyl-group buffering: In mice lacking carnitine acetyltransferase in skeletal muscle, tissue acetyl-CoA rose and diet-induced lysine acetylation of mitochondrial proteins increased, pointing to a role for CrAT and L-carnitine in the muscle acetylproteome [3]
• Gut-microbial metabolism: In mice, chronic dietary L-carnitine altered cecal microbial composition and increased TMA and TMAO synthesis and atherosclerosis, which did not occur when intestinal microbiota were suppressed [4]

Reference citations

1. Bremer J. (1983). Carnitine–metabolism and functions. Physiol Rev, 63(4):1420–1480. PMID 6361812 · DOI
2. Kerner J. et al. (2000). Fatty acid import into mitochondria. Biochim Biophys Acta, 1486(1):1–17. PMID 10856709 · DOI
3. Davies M.N. et al. (2016). The Acetyl Group Buffering Action of Carnitine Acetyltransferase Offsets Macronutrient-Induced Lysine Acetylation of Mitochondrial Proteins. Cell Rep, 14(2):243–254. PMID 26748706 · DOI
4. Koeth R.A. et al. (2013). Intestinal microbiota metabolism of L-carnitine, a nutrient in red meat, promotes atherosclerosis. Nat Med, 19(5):576–585. PMID 23563705 · DOI

Compound data from PubChem CID 10917. Literature summaries describe published preclinical research and are not claims about this product’s effects in humans or animals.