Capric acid

Not to be confused with Caproic acid or Caprylic acid.

Capric acid, also known as decanoic acid or decylic acid, is a saturated fatty acid, medium-chain fatty acid (MCFA), and carboxylic acid. Its formula is CH₃(CH₂)₈COOH. Salts and esters of decanoic acid are called caprates or decanoates. The term capric acid is derived from the Latin "caper / capra" (goat) because the sweaty, unpleasant smell of the compound is reminiscent of goats.^[9]

Decanoic acid

Names
Preferred IUPAC name Decanoic acid
Other names Caprinic acid; Caprynic acid; Decoic acid; Decylic acid; 1-Nonanecarboxylic acid; C10:0 (Lipid numbers)
Identifiers
CAS Number	334-48-5 Y 1002-62-6 (sodium salt) Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:30813 Y
ChEMBL	ChEMBL107498 Y
ChemSpider	2863 Y
DrugBank	DB03600 N
ECHA InfoCard	100.005.798
EC Number	206-376-4
IUPHAR/BPS	5532
KEGG	C01571 Y
PubChem CID	2969
RTECS number	HD9100000
UNII	4G9EDB6V73 Y 4I820XKV2A (sodium salt) Y
CompTox Dashboard (EPA)	DTXSID9021554
InChI InChI=1S/C10H20O2/c1-2-3-4-5-6-7-8-9-10(11)12/h2-9H2,1H3,(H,11,12) Y Key: GHVNFZFCNZKVNT-UHFFFAOYSA-N Y InChI=1/C10H20O2/c1-2-3-4-5-6-7-8-9-10(11)12/h2-9H2,1H3,(H,11,12) Key: GHVNFZFCNZKVNT-UHFFFAOYAC
SMILES O=C(O)CCCCCCCCC
Properties
Chemical formula	C10H20O2
Molar mass	172.268 g·mol−1
Appearance	White crystals
Odor	Strong rancid and unpleasant[1]
Density	0.893 g/cm3 (25 °C)[2] 0.8884 g/cm3 (35.05 °C) 0.8773 g/cm3 (50.17 °C)[3]
Melting point	31.6 °C (88.9 °F; 304.8 K)[4]
Boiling point	268.7 °C (515.7 °F; 541.8 K)[5]
Solubility in water	0.015 g/100 mL (20 °C)[5]
Solubility	Soluble in alcohol, ether, CHCl3, C6H6, CS2, acetone[1]
log P	4.09[5]
Vapor pressure	4.88·10−5 kPa (25 °C)[1] 0.1 kPa (108 °C)[5] 2.03 kPa (160 °C)[6][2]
Acidity (pKa)	4.9[1]
Thermal conductivity	0.372 W/m·K (solid) 0.141 W/m·K (liquid)[3]
Refractive index (nD)	1.4288 (40 °C)[1]
Viscosity	4.327 cP (50 °C)[5] 2.88 cP (70 °C)[3]
Structure
Crystal structure	Monoclinic (−3.15 °C)[7]
Space group	P21/c[7]
Lattice constant	a = 23.1 Å, b = 4.973 Å, c = 9.716 Å[7] α = 90°, β = 91.28°, γ = 90°
Thermochemistry
Heat capacity (C)	475.59 J/mol·K[6]
Std enthalpy of formation (ΔfH⦵298)	−713.7 kJ/mol[5]
Std enthalpy of combustion (ΔcH⦵298)	6079.3 kJ/mol[6]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Medium toxicity
Ingestion hazards	May be toxic
Inhalation hazards	May cause irritation
Skin hazards	May be toxic on contact
GHS labelling:
Pictograms	[2]
Signal word	Warning
Hazard statements	H315, H319, H335[2]
Precautionary statements	P261, P305+P351+P338[2]
NFPA 704 (fire diamond)	[8] 2 1 0
Flash point	110 °C (230 °F; 383 K)[2]
Lethal dose or concentration (LD, LC):
LD50 (median dose)	10 g/kg (rats, oral)[8]
Safety data sheet (SDS)	External MSDS
Related compounds
Related fatty acids	Nonanoic acid, Undecanoic acid
Related compounds	Decanol Decanal
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Occurrence

Capric acid occurs naturally in coconut oil (about 10%) and palm kernel oil (about 4%), otherwise it is uncommon in typical seed oils.^[10] It is found in the milk of various mammals and to a lesser extent in other animal fats.^[4]

Two other acids are named after goats: caproic acid (a C6:0 fatty acid) and caprylic acid (a C8:0 fatty acid). Along with capric acid, these total 15% in goat milk fat.^[11]

Production

Capric acid can be prepared from oxidation of the primary alcohol decanol by using chromium trioxide (CrO₃) oxidant under acidic conditions.^[12]

Neutralization of capric acid or saponification of its triglyceride esters with sodium hydroxide yields sodium caprate, CH₃(CH₂)₈CO−2Na⁺. This salt is a component of some types of soap.

Uses

Capric acid is used in the manufacture of esters for artificial fruit flavors and perfumes. It is also used as an intermediate in chemical syntheses. It is used in organic synthesis and industrially in the manufacture of perfumes, lubricants, greases, rubber, dyes, plastics, food additives and pharmaceuticals.^[8]

Pharmaceuticals

Caprate ester prodrugs of various pharmaceuticals are available. Since capric acid is a fatty acid, forming a salt or ester with a drug will increase its lipophilicity and its affinity for adipose tissue. Since distribution of a drug from fatty tissue is usually slow, one may develop a long-acting injectable form of a drug (called a depot injection) by using its caprate form. Some examples of drugs available as a caprate ester include nandrolone (as nandrolone decanoate),^[13] fluphenazine (as fluphenazine decanoate),^[14] bromperidol (as bromperidol decanoate),^[15] and haloperidol (as haloperidol decanoate).^[15]

Effects

Capric acid acts as a non-competitive AMPA receptor antagonist at therapeutically relevant concentrations, in a voltage- and subunit-dependent manner, and this is sufficient to explain its antiseizure effects.^[16] This direct inhibition of excitatory neurotransmission by capric acid in the brain contributes to the anticonvulsant effect of the MCT ketogenic diet.^[16] Decanoic acid and the AMPA receptor antagonist drug perampanel act at separate sites on the AMPA receptor, and so it is possible that they have a cooperative effect at the AMPA receptor, suggesting that perampanel and the ketogenic diet could be synergistic.^[16]

Capric acid may be responsible for the mitochondrial proliferation associated with the ketogenic diet, and that this may occur via PPARγ receptor agonism and its target genes involved in mitochondrial biogenesis.^[17][18] Complex I activity of the electron transport chain is substantially elevated by decanoic acid treatment.^[17]

It should however be noted that orally ingested medium chain fatty acids would be very rapidly degraded by first-pass metabolism by being taken up in the liver via the portal vein, and are quickly metabolized via coenzyme A intermediates through β-oxidation and the citric acid cycle to produce carbon dioxide, acetate and ketone bodies.^[19] Whether the ketones, β-hydroxybutyrate and acetone have direct antiseizure activity is unclear.^{[16][20][21][22]}

See also

• List of saturated fatty acids
• List of carboxylic acids
• Undecylic acid
• Pelargonic acid, a medium-chain fatty acid, also with antiseizure activity

References

1. CID 2969 from PubChem
2. Sigma-Aldrich Co., Decanoic acid. Retrieved on 2014-06-15.
3. Mezaki, Reiji; Mochizuki, Masafumi; Ogawa, Kohei (2000). Engineering Data on Mixing (1st ed.). Elsevier Science B.V. p. 278. ISBN 978-0-444-82802-6.
4. Beare-Rogers, J. L.; Dieffenbacher, A.; Holm, J.V. (1 January 2001). "Lexicon of lipid nutrition (IUPAC Technical Report)". Pure and Applied Chemistry. 73 (4): 685–744. doi:10.1351/pac200173040685. S2CID 84492006.
5. Lide, David R., ed. (2009). CRC Handbook of Chemistry and Physics (90th ed.). Boca Raton, Florida: CRC Press. ISBN 978-1-4200-9084-0.
6. n-Decanoic acid in Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD) (retrieved 2014-06-15)
7. D. Bond, Andrew (2004). "On the crystal structures and melting point alternation of the n -alkyl carboxylic acids". New Journal of Chemistry. 28 (1): 104–114. doi:10.1039/B307208H.
8. "CAPRIC ACID". chemicalland21.com. AroKor Holdings. Archived from the original on 2018-10-19. Retrieved 2014-06-15.
9. "capri-, capr- +". Archived from the original on 2017-12-23. Retrieved 2012-09-28.
10. David J. Anneken, Sabine Both, Ralf Christoph, Georg Fieg, Udo Steinberner, Alfred Westfechtel "Fatty Acids" in Ullmann's Encyclopedia of Industrial Chemistry, 2006, Wiley-VCH, Weinheim. doi:10.1002/14356007.a10_245.pub2
11. Hilditch, T. P.; Jasperson, H. (1944). "The component acids of milk fats of the goat, ewe and mare". Biochemical Journal. 38 (5): 443–447. doi:10.1042/bj0380443. PMC 1258125. PMID 16747831.
12. McMurry, John (2008). Organic Chemistry (7th ed.). Thompson - Brooks/Cole. p. 624.
13. "ROLON 250mg/ml Solution for Injection - Summary of Product Characteristics (SmPC) - (emc)". www.medicines.org.uk. Archived from the original on 2020-09-22. Retrieved 2020-10-09.
14. "fluphenazine decanoate". The American Society of Health-System Pharmacists. Archived from the original on 8 December 2015. Retrieved 1 December 2015.
15. J. Elks, ed. (14 November 2014). The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies. Springer. pp. 182–. ISBN 978-1-4757-2085-3. OCLC 1058412474.
16. Chang, Pishan; Augustin, Katrin; Boddum, Kim; Williams, Sophie; Sun, Min; Terschak, John A.; Hardege, Jörg D.; Chen, Philip E.; Walker, Matthew C.; Williams, Robin S. B. (February 2016). "Seizure control by decanoic acid through direct AMPA receptor inhibition". Brain. 139 (2): 431–443. doi:10.1093/brain/awv325. PMC 4805082. PMID 26608744.
17. Hughes, Sean David; Kanabus, Marta; Anderson, Glenn; Hargreaves, Iain P.; Rutherford, Tricia; Donnell, Maura O’; Cross, J. Helen; Rahman, Shamima; Eaton, Simon; Heales, Simon J. R. (May 2014). "The ketogenic diet component decanoic acid increases mitochondrial citrate synthase and complex I activity in neuronal cells". Journal of Neurochemistry. 129 (3): 426–433. doi:10.1111/jnc.12646. PMID 24383952. S2CID 206089968.
18. Malapaka, Raghu R. V.; Khoo, SokKean; Zhang, Jifeng; Choi, Jang H.; Zhou, X. Edward; Xu, Yong; Gong, Yinhan; Li, Jun; Yong, Eu-Leong; Chalmers, Michael J.; Chang, Lin; Resau, James H.; Griffin, Patrick R.; Chen, Y. Eugene; Xu, H. Eric (2 January 2012). "Identification and Mechanism of 10-Carbon Fatty Acid as Modulating Ligand of Peroxisome Proliferator-activated Receptors". Journal of Biological Chemistry. 287 (1): 183–195. doi:10.1074/jbc.M111.294785. PMC 3249069. PMID 22039047.
19. Chang, Pishan; Terbach, Nicole; Plant, Nick; Chen, Philip E.; Walker, Matthew C.; Williams, Robin S.B. (June 2013). "Seizure control by ketogenic diet-associated medium chain fatty acids". Neuropharmacology. 69: 105–114. doi:10.1016/j.neuropharm.2012.11.004. PMC 3625124. PMID 23177536.
20. Viggiano, Andrea; Pilla, Raffaele; Arnold, Patrick; Monda, Marcellino; D׳Agostino, Dominic; Coppola, Giangennaro (August 2015). "Anticonvulsant properties of an oral ketone ester in a pentylenetetrazole-model of seizure". Brain Research. 1618: 50–54. doi:10.1016/j.brainres.2015.05.023. PMID 26026798.
21. Rho, Jong M.; Anderson, Gail D.; Donevan, Sean D.; White, H. Steve (22 April 2002). "Acetoacetate, Acetone, and Dibenzylamine (a Contaminant in l-(+)-β-Hydroxybutyrate) Exhibit Direct Anticonvulsant Actions in Vivo". Epilepsia. 43 (4): 358–361. doi:10.1046/j.1528-1157.2002.47901.x. PMID 11952765. S2CID 31196417.
22. Ma, Weiyuan; Berg, Jim; Yellen, Gary (4 April 2007). "Ketogenic Diet Metabolites Reduce Firing in Central Neurons by Opening KATP Channels". The Journal of Neuroscience. 27 (14): 3618–3625. doi:10.1523/JNEUROSCI.0132-07.2007. PMC 6672398. PMID 17409226.