Carnitine is a quaternary ammonium compound involved in metabolism in most mammals, plants, and some bacteria.[1][2][3][4] In support of energy metabolism, carnitine transports long-chain fatty acids from the cytosol into mitochondria to be oxidized for free energy production, and also participates in removing products of metabolism from cells.[3] Given its key metabolic roles, carnitine is concentrated in tissues like skeletal and cardiac muscle that metabolize fatty acids as an energy source.[3] Generally individuals, including strict vegetarians, synthesize enough L-carnitine in vivo.[1]
Carnitine exists as one of two stereoisomers: the two enantiomers d-carnitine (S-(+)-) and l-carnitine (R-(−)-).[5] Both are biologically active, but only l-carnitine naturally occurs in animals, and d-carnitine is toxic as it inhibits the activity of the l-form.[6] At room temperature, pure carnitine is a whiteish powder, and a water-soluble zwitterion with relatively low toxicity. Derived from amino acids,[7] carnitine was first extracted from meat extracts in 1905, leading to its name from Latin, "caro/carnis" or flesh.[2]
Some individuals with genetic or medical disorders (such as preterm infants) cannot make enough carnitine, requiring dietary supplementation.[1][3][4] Despite common carnitine supplement consumption among athletes for improved exercise performance or recovery, there is insufficient high-quality clinical evidence to indicate it provides any benefit.[3][4]
^ abc"L-Carnitine". Micronutrient Information Center, Linus Pauling Institute, Oregon State University, Corvallis, OR. 2019-12-01. Retrieved 2020-04-29.
^ abcde"Carnitine". Office of Dietary Supplements, US National Institutes of Health. 2017-10-10. Retrieved 2020-04-29.
^ abc"L-carnitine: Uses, benefits and dosage". Drugs.com. 2020-01-20. Retrieved 2020-04-29.
^"Levocarnitine". PubChem, National Library of Medicine, US National Institutes of Health. 2020-04-25. Retrieved 2020-04-29.
^Matsuoka M, Igisu H (July 1993). "Comparison of the effects of L-carnitine, D-carnitine and acetyl-L-carnitine on the neurotoxicity of ammonia". Biochemical Pharmacology. 46 (1): 159–64. doi:10.1016/0006-2952(93)90360-9. PMID 8347126.
^Cox RA, Hoppel CL (December 1973). "Biosynthesis of carnitine and 4-N-trimethylaminobutyrate from 6-N-trimethyl-lysine". The Biochemical Journal. 136 (4): 1083–90. doi:10.1042/bj1361083. PMC 1166060. PMID 4786530.
Carnitine is a quaternary ammonium compound involved in metabolism in most mammals, plants, and some bacteria. In support of energy metabolism, carnitine...
Acetyl-L-carnitine, ALCAR or ALC, is an acetylated form of L-carnitine. It is naturally produced by the human body, and it is available as a dietary supplement...
Carnitine palmitoyltransferase I (CPT1) also known as carnitine acyltransferase I, CPTI, CAT1, CoA:carnitine acyl transferase (CCAT), or palmitoylCoA transferase...
Carnitine palmitoyltransferase II deficiency, sometimes shortened to CPT-II or CPT2, is an autosomal recessively inherited genetic metabolic disorder...
Carnitine O-palmitoyltransferase 2, mitochondrial is an enzyme that in humans is encoded by the CPT2 gene. Carnitine palmitoyltransferase II precursor...
primary carnitine deficiency (SPCD) is an inborn error of fatty acid transport caused by a defect in the transporter responsible for moving carnitine across...
Carnitine palmitoyltransferase I deficiency is a rare metabolic disorder that prevents the body from converting certain fats called long-chain fatty acids(LCFA)...
Carnitine biosynthesis is a method for the endogenous production of L-carnitine, a molecule that is essential for energy metabolism. In humans and many...
membranes. Acyl-carnitine is shuttled inside by a carnitine-acylcarnitine translocase, as a carnitine is shuttled outside. Acyl-carnitine is converted back...
co-A is then exchanged with carnitine (via the enzyme carnitine palmitoyltransferase I) to produce a fatty acid-carnitine complex. This complex is then...
polypeptides, uptake of essential mineral nutrients, and in the production of carnitine, which is key in fatty acid metabolism. Lysine is also often involved...
Vitamin B4: can refer to the distinct chemicals choline, adenine, or carnitine. Choline is synthesized by the human body, but not sufficiently to maintain...
carnitine. This is not due to the drug itself, but to the pivalate anion, which is mostly removed from the body by forming a conjugate with carnitine...
movement. GA1 causes secondary carnitine deficiency, as glutaric acid, like other organic acids, is detoxified by carnitine. Mental retardation may occur...
In enzymology, a carnitine dehydratase (EC 4.2.1.89) is an enzyme that catalyzes the chemical reaction L-carnitine ⇌ {\displaystyle \rightleftharpoons...
Ames, B. N. (2004). "Comparison of the effects of L-carnitine and acetyl-L-carnitine on carnitine levels, ambulatory activity, and oxidative stress biomarkers...
several routes in nature. Well studied are the degradation of choline and carnitine. Trimethylamine is used in the synthesis of choline, tetramethylammonium...
Global Information
(what is this?) (verify)