Nebraskanic acid

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Nebraskanic acid
Nebraskanic acid.svg
Names
Preferred IUPAC name
(7R,15Z,18R)-7,18-Dihydroxytetracos-15-enoic acid
Other names
(7R,15Z,18R)-7,18-Dihydroxytetracosa-15-monoenoic acid
7,18-di-OH-24:1-delta-15c
Identifiers
3D model (JSmol)
  • InChI=1S/C24H46O4/c1-2-3-4-12-17-22(25)18-13-9-7-5-6-8-10-14-19-23(26)20-15-11-16-21-24(27)28/h9,13,22-23,25-26H,2-8,10-12,14-21H2,1H3,(H,27,28)/b13-9-/t22-,23-/m1/s1
    Key: XTSZRMFZUAMBRN-FIIQTUGESA-N
  • CCCCCC[C@H](C/C=C\CCCCCCC[C@H](CCCCCC(=O)O)O)O
Properties
C24H46O4
Molar mass 398.628 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Nebraskanic acid ((7R,15Z,18R)-7,18-dihydroxytetracosa-15-monoenoic acid[1]) is a 24-carbon dihydroxy fatty acid with the chemical formula C
24
H
46
O
4
and molecular weight 398.6 g/mol.[2][3]

Nebraskanic acid was identified as a major component of the seed oil of Chinese violet cress (Orychophragmus violaceus L. O.E.Schulz).[4] This fatty acid also occurs in Chinese violet cress oil with a second 24-carbon dihydroxy fatty acid wuhanic acid [(7R,15Z,18R,21Z)-7,18-dihydroxytetracosa-15,21-dienoic acid]. Nebraskanic and wuhanic acids were named in recognition of the location of their co-discoverers at the University of Nebraska-Lincoln and Huazhong Agricultural University, Wuhan, Hubei, China.

Biosynthesis[edit]

Discontinuous fatty acid elongation pathway for nebraskanic acid biosynthesis.

The proposed biosynthetic pathway of nebraskanic acid is based on biochemical and genetic data obtained from Chinese violet cress seeds.[4] These data are consistent with a biosynthetic pathway that originates from the 12-hydroxylation of oleoyl-CoA by a variant fatty acid desaturase 2 (FAD2) enzyme, followed by partial elongation to a C20 3-OH-CoA intermediate. This intermediate is pulled from the elongation cycle through a process termed "discontinuos elongation" by a variant 3-keotacyl-CoA synthetase or FAE1 and elongated through a continuous or complete cycle. The resulting C22 5-OH fatty acyl-CoA then goes through a continuous elongation cycle that results in the hydroxyl group at the C-7 carbon of the 24-carbon fatty acid chain. This pathway for the biosynthesis of the C-7 hydroxyl group of nebraskanic acid is conceptually similar to the anaerobic pathway for fatty acid desaturation in bacteria.[5] This pathway is genetically supported by the reconstruction of nebraskanic acid synthesis in Arabidopsis seeds by co-expression of a 12-fatty acid hydroxylase gene and a variant FAE1 gene from Orychophragmus violaceus.

Functionality[edit]

Tribology tests of nebraskanic acid- and wuhanic acid-rich Chinese violet cress oil conducted in the BioDiscovery Institute at the University of North Texas showed that this oil has superior high temperature lubricant properties compared to castor oil for metal-on-metal wear at 100 °C.[4] It was speculated that the hydroxyl groups of nebraskanic acid and wuhanic acid allow formation of additional fatty acid esters or estolides on the triacylglycerol molecules in Chinese violet cress oil.[4]

References[edit]

  1. ^ "PlantFAdb: 7,18-di-OH-24:1-delta-15c; Nebraskanic acid; (7R,18R)-7,18-dihydroxy-15-tetracosenoic acid, (15Z)-; 7,18-Dihydroxy-15-tetracosenoic acid, (15Z)-". plantfadb.org.
  2. ^ PubChem. "XTSZRMFZUAMBRN-FIIQTUGESA-N". pubchem.ncbi.nlm.nih.gov. U.S.: U.S. National Library of Medicine, National Center for Biotechnology Information. Retrieved 2019-03-29.
  3. ^ "Proposed biosynthetic pathway for nebraskanic acid The pathway shown is..." ResearchGate. Retrieved 2019-03-29.
  4. ^ a b c d Li, Xiangjun; Teitgen, Alicen M.; Shirani, Asghar; Ling, Juan; Busta, Lucas; Cahoon, Rebecca E.; Zhang, Wei; Li, Zaiyun; Chapman, Kent D.; Berman, Diana; Zhang, Chunyu; Minto, Robert E.; Cahoon, Edgar B. (27 August 2018). "Discontinuous fatty acid elongation yields hydroxylated seed oil with improved function". Nature Plants. 4 (9): 711–720. doi:10.1038/s41477-018-0225-7. PMID 30150614. S2CID 52095084.
  5. ^ NORRIS, AT; BLOCH, K (September 1963). "On the Mechanism of the Enzymatic Synthesis of Unsaturated Fatty Acids in Escherichia Coli". The Journal of Biological Chemistry. 238 (9): 3133–4. doi:10.1016/S0021-9258(18)51880-9. PMID 14081939.