Omega hydroxy acids (ω-hydroxy acids) are a class of naturally occurring straight-chain aliphatic organic acids n carbon atoms long with a carboxyl group at position 1 (the starting point for the family of carboxylic acids), and a hydroxyl at terminal position n where n > 3. They are a subclass of hydroxycarboxylic acids. The C16 and C18 omega hydroxy acids 16-hydroxy palmitic acid and 18-hydroxy stearic acid are key monomers of cutin in the plant cuticle.[1][2] The polymer cutin is formed by interesterification of omega hydroxy acids and derivatives of them that are substituted in mid-chain, such as 10,16-dihydroxy palmitic acid.[3][4] Only the epidermal cells of plants synthesize cutin.[5]

Omega hydroxy fatty acids also occur in animals. Cytochrome P450 (CYP450) microsome ω-hydroxylases such as CYP4A11, CYP4A22, CYP4F2, and CYP4F3 in humans, Cyp4a10 and Cyp4a12 in mice, and Cyp4a1, Cyp4a2, Cyp4a3, and Cyp4a8 in rats metabolize arachidonic acid and many arachidonic acid metabolites to their corresponding omega hydroxyl products.[6] This metabolism of arachidonic acid produces 20-hydroxyarachidonic acid (i.e. 20-hydroxyeicosatetraeonic acid or 20-HETE), a bioactive product involved in various physiological and pathological processes;[7] and this metabolism of certain bioactive arachidonic acid metabolites such as leukotriene B4 and 5-hydroxyicosatetraenoic acid produces 20-hydroxylated products which are 100- to 1,000-fold weaker than, and therefore represents the inactivation of, their respective precursors.[8][9][10]

List

The definition for "omega" includes number of carbons (C#) greater or equal to three. Lower numbers are included here to match the formula pattern CnH2nO3.

C# systematic name trivial name melting point

°C

formula SMILES CASNo PubChem CID ChemSpiderID UNII ChEBI occurrence reference
1 Carbonic acid CH2O3 OC(=O)O 463-79-6 767 747 142M471B3J 28976
2 2-Hydroxyethanoic acid Glycolic acid 75 C2H4O3 OCC(=O)O 79-14-1 757 737 0WT12SX38S 17497 plants
3 3-Hydroxypropionic acid β-Lactic acid 139-140 C3H6O3 OCCC(=O)O 503-66-2 68152 61460 most living organisms
4 4-Hydroxybutanoic acid gamma-Hydroxybutyric acid ? C4H8O3 OCCCC(=O)O 591-81-1 10413 9984 30IW36W5B2 30830 human neurotransmitter
5 5-Hydroxypentanoic acid 5-hydroxyvaleric acid C5H10O3 OCCCCC(=O)O 13392-69-3 25945 24171 H5EVV4LP59 45564
6 6-Hydroxyhexanoic acid 6-Hydroxycaproic acid C6H12O3 OCCCCCC(=O)O 1191-25-9 14490 13835 3Y3OX37NM8 17869
7 7-Hydroxyheptanoic acid C7H14O3 OCCCCCCC(=O)O 3710-42-7 138016 121660 79112
8 8-Hydroxyoctanoic acid omega-hydroxycaprylic acid C8H16O3 OCCCCCCCC(=O)O 764-89-6 69820 63018 79162
9 9-Hydroxynonanoic acid 9-hydroxypelargonic acid C9H18O3 OCCCCCCCCC(=O)O 3788-56-5 138052 121694 HV672SU12G 79121
10 10-Hydroxydecanoic acid 10-hydroxy capric acid C10H20O3 OCCCCCCCCCC(=O)O 1679-53-4 74300 66903 NP03XO416B 17409
11 11-Hydroxyundecanoic acid 11-HUDA C11H22O3 OCCCCCCCCCCC(=O)O 3669-80-5 77237 69664 SD6J9LX2XK 79126
12 12-Hydroxydodecanoic acid Sabinic acid C12H24O3 OCCCCCCCCCCCC(=O)O 505-95-3 79034 71366 SUH3LR2K9D 39567 [11]
13 13-Hydroxytridecanoic acid C13H26O3 OCCCCCCCCCCCCC(=O)O 7735-38-8 139065 122656 79166
14 14-Hydroxytetradecanoic acid ω-hydroxy myristic acid C14H28O3 OCCCCCCCCCCCCCC(=O)O 17278-74-9 084276 2341369 77168
15 15-Hydroxypentadecanoic acid C15H30O3 OCCCCCCCCCCCCCCC(=O)O 4617-33-8 78360 70730 FU65P3692T 79169 Angelica archangelica
16 16-hydroxyhexadecanoic acid Juniperic acid C16H32O3 OCCCCCCCCCCCCCCCC(=O)O 506-13-8 10466 10034 55328 plant cuticle [12]
17 17-Hydroxyheptadecanoic acid C17H34O3 OCCCCCCCCCCCCCCCCC(=O)O 13099-34-8 4308451 3513977 79177 Pinus radiata
18 18-Hydroxyoctadecanoic acid ω-hydroxystearic acid C18H36O3 OCCCCCCCCCCCCCCCCCC(=O)O 3155-42-8 5282915 4446042 CCR5P6ICT2 79182 plant cutin
19 19-Hydroxynonadecanoic acid C19H38O3 OCCCCCCCCCCCCCCCCCCC(=O)O 5282917 4446044 79179
20 20-Hydroxyicosanoic acid ω-hydroxyarachidic acid C20H40O3 OCCCCCCCCCCCCCCCCCCCC(=O)O 62643-46-3 5282919 4446046 79190 stem and seed cutin
21 21-Hydroxyhenicosanoic acid C21H42O3 OCCCCCCCCCCCCCCCCCCCCC(=O)O 5282920 4446047 79195
22 22-Hydroxydocosanoic acid 22-hydroxybehenic acid C22H44O3 OCCCCCCCCCCCCCCCCCCCCCC(=O)O 506-45-6 5282922 4446049 76322
23 23-Hydroxytricosanoic acid C23H46O3 OCCCCCCCCCCCCCCCCCCCCCCC(=O)O 61658-18-2 11760442 9935141 cutin
24 24-Hydroxytetracosanoic acid C24H48O3 OCCCCCCCCCCCCCCCCCCCCCCCC(=O)O 75912-18-4 5312780 4472205
25 25-Hydroxypentacosanoic acid C25H50O3 OCCCCCCCCCCCCCCCCCCCCCCCCC(=O)O 82612-07-5 14325176 57507583
26 26-Hydroxyhexacosanoic acid ω-hydroxycerotic acid C26H52O3 OCCCCCCCCCCCCCCCCCCCCCCCCCC(=O)O 506-47-8 5312785 4472210 76325
27 27-Hydroxyheptacosanoic acid C27H54O3 OCCCCCCCCCCCCCCCCCCCCCCCCCCC(=O)O 14325177 13739624 84861
28 28-Hydroxyoctacosanoic acid C28H56O3 OCCCCCCCCCCCCCCCCCCCCCCCCCCCC(=O)O 52900-17-1 5312786 4472211 84863
29 29-hydroxynonacosanoic acid omega-Hydroxynonacosanoic acid C29H58O3 OCCCCCCCCCCCCCCCCCCCCCCCCCCCCC(=O)O 14325178 34449103 84865
30 30-Hydroxytriacontanoic acid C30H60O3 OCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC(=O)O 52900-18-2 5312787 4472212 76220

See also

References

  1. ^ Kolattukudy, P. E.; Walton, T. J. (1972). "Structure and biosynthesis of the hydroxy fatty acids of cutin in Vicia faba leaves". Biochemistry. 11 (10): 1897–1907. doi:10.1021/bi00760a026. PMID 5025632.
  2. ^ Soliday, C. L.; Kolattukudy, P. E. (1977). "Biosynthesis of Cutin ω-hydroxylation of fatty acids by a microsomal preparation from germinating Vicia faba". Plant Physiology. 59 (6): 1116–1121. doi:10.1104/pp.59.6.1116. PMC 542517. PMID 16660004.
  3. ^ T.J. Walton TJ and P.E. Kolattukudy (1972) Enzymatic conversion of 16-hydroxypalmitic acid into 10,16-dihydroxypalmitic acid in Vicia faba epidermal extracts. Biochem Biophys Res Communications 46, (1), 16–21
  4. ^ P. J. Holloway (1982) The chemical constitution of plant cutins. p45-85 in In "The Plant Cuticle". ed. by DF Cutler, KL Alvin and CE Price. Academic Press, London. ISBN 0-12-199920-3
  5. ^ Kolattukudy, PE (1996) Biosynthetic pathways of cutin and waxes, and their sensitivity to environmental stresses. In: Plant Cuticles. Ed. by G. Kerstiens, BIOS Scientific publishers, Oxford, pp 83-108
  6. ^ Hoopes SL, Garcia V, Edin ML, Schwartzman ML, Zeldin DC (Jul 2015). "Vascular actions of 20-HETE". Prostaglandins & Other Lipid Mediators. 120: 9–16. doi:10.1016/j.prostaglandins.2015.03.002. PMC 4575602. PMID 25813407.
  7. ^ Annu Rev Pharmacol Toxicol. 2005;45:413-38
  8. ^ Du, L; Yin, H; Morrow, JD; Strobel, HW; Keeney, DS (2009). "20-Hydroxylation is the CYP-dependent and retinoid-inducible leukotriene B4 inactivation pathway in human and mouse skin cells". Archives of Biochemistry and Biophysics. 484 (1): 80–86. doi:10.1016/j.abb.2009.01.012. PMC 2687325. PMID 19467632.
  9. ^ J Immunol. 1986 Nov 15;137(10):3277-83
  10. ^ Powell, WS; Rokach, J (Apr 2015). "Biosynthesis, biological effects, and receptors of hydroxyeicosatetraenoic acids (HETEs) and oxoeicosatetraenoic acids (oxo-ETEs) derived from arachidonic acid". Biochim Biophys Acta. 1851 (4): 340–355. doi:10.1016/j.bbalip.2014.10.008. PMC 5710736. PMID 25449650.
  11. ^ Lycan, W. H.; Adams, Roger (February 1929). "Omega-Hydroxy Aliphatic Acids. Synthesis of Sabinic Acid". Journal of the American Chemical Society. 51 (2): 625–629. doi:10.1021/ja01377a042. ISSN 0002-7863.
  12. ^ Spring, F. S. (March 1945). "Naturally Occurring Polyesters". Nature. 155 (3931): 272. Bibcode:1945Natur.155..272S. doi:10.1038/155272b0. ISSN 0028-0836. S2CID 4108900.
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