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Record Information
StatusDetected and Quantified
Creation Date2010-02-22 12:02:22 UTC
Update Date2021-04-12 19:32:10 UTC
Secondary Accession Numbers
  • HMDB13336
Metabolite Identification
Common Name3-Hydroxyhexadecanoylcarnitine
Description3-Hydroxyhexadecanoylcarnitine is an acylcarnitine. More specifically, it is an 3-hydroxyhexadecanoic acid ester of carnitine. Acylcarnitines were first discovered more than 70 year ago (PMID: 13825279 ). It is believed that there are more than 1000 types of acylcarnitines in the human body. The general role of acylcarnitines is to transport acyl-groups (organic acids and fatty acids) from the cytoplasm into the mitochondria so that they can be broken down to produce energy.  This process is known as beta-oxidation. According to a recent review [Dambrova et al. 2021, Physiological Reviews], acylcarnitines (ACs) can be classified into 9 different categories depending on the type and size of their acyl-group: 1) short-chain ACs; 2) medium-chain ACs; 3) long-chain ACs; 4) very long-chain ACs; 5) hydroxy ACs; 6) branched chain ACs; 7) unsaturated ACs; 8) dicarboxylic ACs and 9) miscellaneous ACs. Short-chain ACs have acyl-groups with two to five carbons (C2-C5), medium-chain ACs have acyl-groups with six to thirteen carbons (C6-C13), long-chain ACs have acyl-groups with fourteen to twenty once carbons (C14-C21) and very long-chain ACs have acyl groups with more than 22 carbons. 3-Hydroxyhexadecanoylcarnitine is therefore classified as a long chain AC. As a long-chain acylcarnitine 3-hydroxyhexadecanoylcarnitine is generally formed through esterification with long-chain fatty acids obtained from the diet. The main function of most long-chain acylcarnitines is to ensure long chain fatty acid transport into the mitochondria (PMID: 22804748 ). Altered levels of long-chain acylcarnitines can serve as useful markers for inherited disorders of long-chain fatty acid metabolism. In particular 3-hydroxyhexadecanoylcarnitine is elevated in the blood or plasma of individuals with type 2 diabetes mellitus (PMID: 24358186 , PMID: 32708684 , PMID: 24837145 ), long-chain 3-hydroxy acyl CoA dehydrogenase deficiency (PMID: 25888220 ), and mitochondrial trifunctional protein deficiency (PMID: 19880769 ). It is also decreased in the blood or plasma of individuals with psoriasis (PMID: 33391503 ). 3-Hydroxyhexadecanoylcarnitine can be found in urine and faces as well. Carnitine palmitoyltransferase I (CPT I, EC: is involved in the synthesis of long-chain acylcarnitines (more than C12) on the mitochondrial outer membrane.  Elevated serum/plasma levels of long-chain acylcarnitines are not only markers for incomplete FA oxidation but also are indicators of altered carbohydrate and lipid metabolism. High serum concentrations of long-chain acylcarnitines in the postprandial or fed state are markers of insulin resistance and arise from insulin's inability to inhibit CPT-1-dependent fatty acid metabolism in muscles and the heart (PMID: 19073774 ). Increased intracellular content of long-chain acylcarnitines is thought to serve as a feedback inhibition mechanism of insulin action (PMID: 23258903 ). In healthy subjects, increased concentrations of insulin effectively inhibits long-chain acylcarnitine production. Several studies have also found increased levels of circulating long-chain acylcarnitines in chronic heart failure patients (PMID: 26796394 ). The study of acylcarnitines is an active area of research and it is likely that many novel acylcarnitines will be discovered in the coming years. It is also likely that many novel roles in health and disease will be uncovered. An excellent review of the current state of knowledge for acylcarnitines is available at [Dambrova et al. 2021, Physiological Reviews].
(3R)-3-[(3-Hydroxyhexadecanoyl)oxy]-4-(trimethylazaniumyl)butanoic acidGenerator
Chemical FormulaC23H45NO5
Average Molecular Weight415.615
Monoisotopic Molecular Weight415.329773553
IUPAC Name(3R)-3-[(3-hydroxyhexadecanoyl)oxy]-4-(trimethylazaniumyl)butanoate
Traditional Name(3R)-3-[(3-hydroxyhexadecanoyl)oxy]-4-(trimethylammonio)butanoate
CAS Registry Number195207-76-2
InChI Identifier
Chemical Taxonomy
Description belongs to the class of organic compounds known as acyl carnitines. These are organic compounds containing a fatty acid with the carboxylic acid attached to carnitine through an ester bond.
KingdomOrganic compounds
Super ClassLipids and lipid-like molecules
ClassFatty Acyls
Sub ClassFatty acid esters
Direct ParentAcyl carnitines
Alternative Parents
  • Acyl-carnitine
  • Beta-hydroxy acid
  • Dicarboxylic acid or derivatives
  • Hydroxy acid
  • Tetraalkylammonium salt
  • Quaternary ammonium salt
  • Carboxylic acid ester
  • Carboxylic acid salt
  • Secondary alcohol
  • Carboxylic acid derivative
  • Carboxylic acid
  • Organic nitrogen compound
  • Organonitrogen compound
  • Organooxygen compound
  • Organic zwitterion
  • Organic salt
  • Hydrocarbon derivative
  • Organic oxide
  • Organopnictogen compound
  • Carbonyl group
  • Organic oxygen compound
  • Amine
  • Alcohol
  • Aliphatic acyclic compound
Molecular FrameworkAliphatic acyclic compounds
External DescriptorsNot Available

Biological location:


Physical Properties
Experimental Properties
Melting PointNot AvailableNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Predicted Properties
Water Solubility8.9e-05 g/LALOGPS
pKa (Strongest Acidic)4.1ChemAxon
pKa (Strongest Basic)-2.8ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count4ChemAxon
Hydrogen Donor Count1ChemAxon
Polar Surface Area86.66 ŲChemAxon
Rotatable Bond Count20ChemAxon
Refractivity138.59 m³·mol⁻¹ChemAxon
Polarizability50.99 ųChemAxon
Number of Rings0ChemAxon
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Not Available
Biological Properties
Cellular LocationsNot Available
Biospecimen Locations
  • Blood
  • Feces
  • Urine
Tissue LocationsNot Available
Normal Concentrations
BloodDetected but not QuantifiedNot QuantifiedAdult (>18 years old)BothNormal details
BloodDetected and Quantified0.0050-0.0200 uMAdult (>18 years old)Both
FecesDetected and Quantified0.26 +/- 0.14 nmol/g wet fecesAdult (>18 years old)Both
FecesDetected and Quantified0.24 +/- 0.1 nmol/g wet fecesAdult (>18 years old)Both
UrineDetected and Quantified0.0015 (0.0006-0.0050) umol/mmol creatinineAdult (>18 years old)Both
UrineDetected but not QuantifiedNot QuantifiedAdult (>18 years old)BothNormal details
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDNot Available
Phenol Explorer Compound IDNot Available
FooDB IDFDB029396
KNApSAcK IDNot Available
Chemspider IDNot Available
KEGG Compound IDNot Available
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia LinkNot Available
METLIN IDNot Available
PubChem Compound126456228
PDB IDNot Available
ChEBI IDNot Available
Food Biomarker OntologyNot Available
MarkerDB ID
Synthesis ReferenceNot Available
Material Safety Data Sheet (MSDS)Not Available
General References
  1. FRITZ IB: Action of carnitine on long chain fatty acid oxidation by liver. Am J Physiol. 1959 Aug;197:297-304. doi: 10.1152/ajplegacy.1959.197.2.297. [PubMed:13825279 ]
  2. Reuter SE, Evans AM: Carnitine and acylcarnitines: pharmacokinetic, pharmacological and clinical aspects. Clin Pharmacokinet. 2012 Sep 1;51(9):553-72. doi: 10.1007/BF03261931. [PubMed:22804748 ]
  3. Mai M, Tonjes A, Kovacs P, Stumvoll M, Fiedler GM, Leichtle AB: Serum levels of acylcarnitines are altered in prediabetic conditions. PLoS One. 2013 Dec 16;8(12):e82459. doi: 10.1371/journal.pone.0082459. eCollection 2013. [PubMed:24358186 ]
  4. Hameed A, Mojsak P, Buczynska A, Suleria HAR, Kretowski A, Ciborowski M: Altered Metabolome of Lipids and Amino Acids Species: A Source of Early Signature Biomarkers of T2DM. J Clin Med. 2020 Jul 16;9(7). pii: jcm9072257. doi: 10.3390/jcm9072257. [PubMed:32708684 ]
  5. Zhang X, Zhang C, Chen L, Han X, Ji L: Human serum acylcarnitine profiles in different glucose tolerance states. Diabetes Res Clin Pract. 2014 Jun;104(3):376-82. doi: 10.1016/j.diabres.2014.04.013. Epub 2014 Apr 28. [PubMed:24837145 ]
  6. Karall D, Brunner-Krainz M, Kogelnig K, Konstantopoulou V, Maier EM, Moslinger D, Plecko B, Sperl W, Volkmar B, Scholl-Burgi S: Clinical outcome, biochemical and therapeutic follow-up in 14 Austrian patients with Long-Chain 3-Hydroxy Acyl CoA Dehydrogenase Deficiency (LCHADD). Orphanet J Rare Dis. 2015 Feb 22;10:21. doi: 10.1186/s13023-015-0236-7. [PubMed:25888220 ]
  7. Park HD, Kim SR, Ki CS, Lee SY, Chang YS, Jin DK, Park WS: Two novel HADHB gene mutations in a Korean patient with mitochondrial trifunctional protein deficiency. Ann Clin Lab Sci. 2009 Fall;39(4):399-404. [PubMed:19880769 ]
  8. Chen C, Hou G, Zeng C, Ren Y, Chen X, Peng C: Metabolomic profiling reveals amino acid and carnitine alterations as metabolic signatures in psoriasis. Theranostics. 2021 Jan 1;11(2):754-767. doi: 10.7150/thno.51154. eCollection 2021. [PubMed:33391503 ]
  9. Bruce CR, Hoy AJ, Turner N, Watt MJ, Allen TL, Carpenter K, Cooney GJ, Febbraio MA, Kraegen EW: Overexpression of carnitine palmitoyltransferase-1 in skeletal muscle is sufficient to enhance fatty acid oxidation and improve high-fat diet-induced insulin resistance. Diabetes. 2009 Mar;58(3):550-8. doi: 10.2337/db08-1078. Epub 2008 Dec 10. [PubMed:19073774 ]
  10. Schooneman MG, Vaz FM, Houten SM, Soeters MR: Acylcarnitines: reflecting or inflicting insulin resistance? Diabetes. 2013 Jan;62(1):1-8. doi: 10.2337/db12-0466. [PubMed:23258903 ]
  11. Ahmad T, Kelly JP, McGarrah RW, Hellkamp AS, Fiuzat M, Testani JM, Wang TS, Verma A, Samsky MD, Donahue MP, Ilkayeva OR, Bowles DE, Patel CB, Milano CA, Rogers JG, Felker GM, O'Connor CM, Shah SH, Kraus WE: Prognostic Implications of Long-Chain Acylcarnitines in Heart Failure and Reversibility With Mechanical Circulatory Support. J Am Coll Cardiol. 2016 Jan 26;67(3):291-9. doi: 10.1016/j.jacc.2015.10.079. [PubMed:26796394 ]