Record Information
Creation date2010-04-08 22:04:37 UTC
Update date2019-11-26 02:55:01 UTC
Primary IDFDB000572
Secondary Accession NumbersNot Available
Chemical Information
FooDB NameL-carnitine
DescriptionUsed in sport and infant nutrition. Carnitine is a quaternary ammonium compound biosynthesized from the amino acids lysine and methionine. In living cells, it is required for the transport of fatty acids from the cytosol into the mitochondria during the breakdown of lipids (or fats) for the generation of metabolic energy. It is often sold as a nutritional supplement. Carnitine was originally found as a growth factor for mealworms and labeled vitamin Bt. Carnitine exists in two stereoisomers: its biologically active form is L-carnitine, while its enantiomer, D-carnitine, is biologically inactive.; Carnitine is not an essential amino acid; Levocarnitine is a carrier molecule in the transport of long chain fatty acids across the inner mitochondrial membrane. It also exports acyl groups from subcellular organelles and from cells to urine before they accumulate to toxic concentrations. Lack of carnitine can lead to liver, heart, and muscle problems. Carnitine deficiency is defined biochemically as abnormally low plasma concentrations of free carnitine, less than 20 µmol/L at one week post term and may be associated with low tissue and/or urine concentrations. Further, this condition may be associated with a plasma concentration ratio of acylcarnitine/levocarnitine greater than 0.4 or abnormally elevated concentrations of acylcarnitine in the urine. Only the L isomer of carnitine (sometimes called vitamin BT) affects lipid metabolism. The "vitamin BT" form actually contains D,L-carnitine, which competitively inhibits levocarnitine and can cause deficiency. Levocarnitine can be used therapeutically to stimulate gastric and pancreatic secretions and in the treatment of hyperlipoproteinemias.; There is a close correlation between changes in plasma levels of osteocalcin and osteoblast activity and a reduction in osteocalcin plasma levels is an indicator of reduced osteoblast activity, which appears to underlie osteoporosis in elderly subjects and in postmenopausal women. Administration of a carnitine mixture or propionyl-L-carnitine is capable of increasing serum osteocalcin concentrations of animals thus treated, whereas serum osteocalcin levels tend to decrease with age in control animals.; it can be synthesized in the body. However, it is so important in providing energy to muscles including the heart-that some researchers are now recommending carnitine supplements in the diet, particularly for people who do not consume much red meat, the main food source for carnitine. Carnitine has been described as a vitamin, an amino acid, or a metabimin, i.e., an essential metabolite. Like the B vitamins, carnitine contains nitrogen and is very soluble in water, and to some researchers carnitine is a vitamin (Liebovitz 1984). It was found that an animal (yellow mealworm) could not grow without carnitine in its diet. However, as it turned out, almost all other animals, including humans, do make their own carnitine; thus, it is no longer considered a vitamin. Nevertheless, in certain circumstances-such as deficiencies of methionine, lysine or vitamin C or kidney dialysis--carnitine shortages develop. Under these conditions, carnitine must be absorbed from food, and for this reason it is sometimes referred to as a "metabimin" or a conditionally essential metabolite. Like the other amino acids used or manufactured by the body, carnitine is an amine. But like choline, which is sometimes considered to be a B vitamin, carnitine is also an alcohol (specifically, a trimethylated carboxy-alcohol). Thus, carnitine is an unusual amino acid and has different functions than most other amino acids, which are most usually employed by the body in the construction of protein. Carnitine is an essential factor in fatty acid metabolism in mammals. It's most important known metabolic function is to transport fat into the mitochondria of muscle cells, including those in the heart, for oxidation. This is how the heart gets most of its energy. In humans, about 25% of carnitine is synthesized in the liver, kidney and brain from the amino acids lysine and methionine. Most of the carnitine in the body comes from dietary sources such as red meat and dairy products. Inborn errors of carnitine metabolism can lead to brain deterioration like that of Reye's syndrome, gradually worsening muscle weakness, Duchenne-like muscular dystrophy and extreme muscle weakness with fat accumulation in muscles. Borurn et al. (1979) describe carnitine as an essential nutrient for pre-term babies, certain types (non-ketotic) of hypoglycemics, kidney dialysis patients, cirrhosis, and in kwashiorkor, type IV hyperlipidemia, heart muscle disease (cardiomyopathy), and propionic or organic aciduria (acid urine resulting from genetic or other anomalies). In all these conditions and the inborn errors of carnitine metabolism, carnitine is essential to life and carnitine supplements are valuable. carnitine therapy may also be useful in a wide variety of clinical conditions. carnitine supplementation has improved some patients who have angina secondary to coronary artery disease. It may be worth a trial in any form of hyperlipidemia or muscle weakness. carnitine supplements may be useful in many forms of toxic or metabolic liver disease and in cases of heart muscle disease. Hearts undergoing severe arrhythmia quickly deplete their stores of carnitine. Athletes, particularly in Europe, have used carnitine supplements for improved endurance. carnitine may improve muscle building by improving fat utilization and may even be useful in treating obesity. carnitine joins a long list of nutrients which may be of value in treating pregnant women, hypothyroid individuals, and male infertility due to low motility of sperm. Even the Physician's Desk Reference gives indication for carnitine supplements as "improving the tolerance of ischemic heart disease, myocardial insufficiencies, and type IV hyperlipoproteinemia. carnitine deficiency is noted in abnormal liver function, renal dialysis patients, and severe to moderate muscular weakness with associated anorexia." ( Carnitine is a biomarker for the consumption of meat. L-carnitine is found in pulses and common pea.
CAS Number541-15-1
L CarnitineMeSH
Vitamin BTMeSH
(R)-(3-Carboxy-2-hydroxypropyl)trimethylammonium hydroxidebiospider
3-Carboxy-2-hydroxy-N,N,N-trimethyl-1-propanaminium hydroxide, inner saltChEBI
3-hydroxy-4-trimethylammoniobutanoic acidbiospider
Carniking 50HMDB
Carnipass 20HMDB
Carnitine, INN; L-formdb_source
Levocarnitine, BAN, INN, USANdb_source
Predicted Properties
Water Solubility5.33 g/LALOGPS
pKa (Strongest Acidic)4.2ChemAxon
pKa (Strongest Basic)-3.6ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count1ChemAxon
Polar Surface Area60.36 ŲChemAxon
Rotatable Bond Count4ChemAxon
Refractivity63.49 m³·mol⁻¹ChemAxon
Polarizability16.76 ųChemAxon
Number of Rings0ChemAxon
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Chemical FormulaC7H15NO3
IUPAC name3-hydroxy-4-(trimethylazaniumyl)butanoate
InChI IdentifierInChI=1S/C7H15NO3/c1-8(2,3)5-6(9)4-7(10)11/h6,9H,4-5H2,1-3H3
Isomeric SMILESC[N+](C)(C)CC(O)CC([O-])=O
Average Molecular Weight161.1989
Monoisotopic Molecular Weight161.105193351
Description Belongs to the class of organic compounds known as carnitines. These are organic compounds containing the quaternary ammonium compound carnitine.
KingdomOrganic compounds
Super ClassOrganic nitrogen compounds
ClassOrganonitrogen compounds
Sub ClassQuaternary ammonium salts
Direct ParentCarnitines
Alternative Parents
  • Carnitine
  • Beta-hydroxy acid
  • Short-chain hydroxy acid
  • Fatty acid
  • Hydroxy acid
  • Tetraalkylammonium salt
  • 1,2-aminoalcohol
  • Carboxylic acid salt
  • Secondary alcohol
  • Carboxylic acid derivative
  • Carboxylic acid
  • Monocarboxylic acid or derivatives
  • Organic oxygen compound
  • Organooxygen compound
  • Organic zwitterion
  • Organic salt
  • Hydrocarbon derivative
  • Organic oxide
  • Carbonyl group
  • Organopnictogen compound
  • Amine
  • Alcohol
  • Aliphatic acyclic compound
Molecular FrameworkAliphatic acyclic compounds
External Descriptors


Physico-Chemical Properties - Experimental
Physico-Chemical Properties - Experimental
Physical stateSolid
Physical DescriptionNot Available
Mass CompositionC 52.16%; H 9.38%; N 8.69%; O 29.78%DFC
Melting PointMp 196-198°DFC
Boiling PointNot Available
Experimental Water SolubilityNot Available
Experimental logPNot Available
Experimental pKa3.8
Isoelectric pointNot Available
ChargeNot Available
Optical Rotation[a]25D -31.3 (c, 10 in H2O) (>99% op)DFC
Spectroscopic UV DataNot Available
DensityNot Available
Refractive IndexNot Available
TypeDescriptionSplash KeyView
Predicted GC-MSCarnitine, non-derivatized, Predicted GC-MS Spectrum - 70eV, Positivesplash10-00di-9100000000-cb5ff6f49357fa7dac62Spectrum
Predicted GC-MSCarnitine, 1 TMS, Predicted GC-MS Spectrum - 70eV, Positivesplash10-00di-9100000000-c15eaa190d1e28a4839aSpectrum
TypeDescriptionSplash KeyView
Predicted MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-01ox-0900000000-3bffd5143cf8b072299e2017-10-06View Spectrum
Predicted MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-00kf-0900000000-e68f553bcb15d3ef5b472017-10-06View Spectrum
Predicted MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-00di-9200000000-c5b43723951af6da48cf2017-10-06View Spectrum
Predicted MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-03di-1900000000-dd1b1a023937cdcb11af2017-10-06View Spectrum
Predicted MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-114i-3900000000-9f24d3bc535736149e2a2017-10-06View Spectrum
Predicted MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-0a4l-9000000000-632ef17d9dde385869902017-10-06View Spectrum
NMRNot Available
ChemSpider ID2006614
KEGG Compound IDC00318
Pubchem Compound ID10917
Pubchem Substance IDNot Available
ChEBI ID16347
Phenol-Explorer IDNot Available
DrugBank IDDB00583
CRC / DFC (Dictionary of Food Compounds) IDBDS79-T:BDS82-P
Dr. Duke IDNot Available
BIGG ID34600
KNApSAcK IDNot Available
Food Biomarker OntologyNot Available
VMH IDNot Available
Flavornet IDNot Available
GoodScent IDNot Available
SuperScent IDNot Available
Wikipedia IDL-Carnitine
Phenol-Explorer Metabolite IDNot Available
Duplicate IDSNot Available
Old DFC IDSNot Available
Associated Foods
FoodContent Range AverageReference
Biological Effects and Interactions
Health Effects / BioactivitiesNot Available
NameGene NameUniProt ID
Carnitine O-acetyltransferaseCRATP43155
Peroxisomal carnitine O-octanoyltransferaseCROTQ9UKG9
Carnitine O-palmitoyltransferase 1, muscle isoformCPT1BQ92523
Carnitine O-palmitoyltransferase 1, liver isoformCPT1AP50416
Carnitine O-palmitoyltransferase 2, mitochondrialCPT2P23786
Carnitine O-palmitoyltransferase 1, brain isoformCPT1CQ8TCG5
Liver carboxylesterase 1CES1P23141
Mitochondrial carnitine/acylcarnitine carrier proteinSLC25A20O43772
Beta Oxidation of Very Long Chain Fatty AcidsSMP00052 map01040
Carnitine SynthesisSMP00465 Not Available
Mitochondrial Beta-Oxidation of Long Chain Saturated Fatty AcidsSMP00482 Not Available
Mitochondrial Beta-Oxidation of Short Chain Saturated Fatty AcidsSMP00480 Not Available
Oxidation of Branched Chain Fatty AcidsSMP00030 Not Available
MetabolismNot Available
BiosynthesisNot Available
Organoleptic Properties
FlavoursNot Available
Synthesis ReferenceNot Available
General ReferenceNot Available
Content Reference