Ricinoleic acid
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| General | ||||||||||||||||||||||
| Surname | Ricinoleic acid | |||||||||||||||||||||
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| Molecular formula | C 18 H 34 O 3 | |||||||||||||||||||||
| Brief description |
Yellowish, viscous liquid |
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| properties | ||||||||||||||||||||||
| Molar mass | 298.47 g · mol -1 | |||||||||||||||||||||
| Physical state |
liquid |
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| density |
0.94 g cm −3 |
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| Melting point |
5.5 ° C |
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| boiling point |
245 ° C (13 h Pa ) |
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| solubility |
almost insoluble in water, easily soluble in ethanol , glacial acetic acid , diethyl ether and chloroform |
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| Refractive index |
1.4716 (21 ° C) |
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C | ||||||||||||||||||||||
Ricinoleic acid (according to IUPAC : (9 Z , 12 R ) -12-hydroxyoctadec-9-enoic acid) is an unsaturated, linearly built omega-9 fatty acid with the empirical formula C 18 H 34 O 3 . At room temperature, the compound is an oily, yellow, water- insoluble liquid . It has a hydroxyl group on the 12th C atom . The double bond between the 9th and 10th carbon atom has a cis configuration.
Occurrence and extraction
It occurs in the seed oil of several plant species, the largest source is the miracle tree ( Ricinus communis ), its common name is also derived from the plant. But it also occurs in smaller amounts in several other plant species, e.g. B. in Lesquerella species and also in flax species. Ricinoleic acid is the only natural fatty acid that is commercially available in large quantities and that carries a hydroxyl group. It is obtained by hydrolysis of castor oil , in which 85 to 92 % of the substance occurs in the form of triglycerides . To biosynthesis are relevant investigations.
Lesquerolic acid (11 Z , 14 R ) -14-hydroxy-11-icosenoic acid, which is two carbon atoms longer, is a homologue and is also in industrial demand.
Analytics
The qualitative and quantitative determination in the various test materials succeeds after appropriate sample preparation by gas chromatography of the methyl esters or the trimethylsilyl ethers ( derivatisation of the OH group). The coupling of gas chromatography with mass spectrometry is also suitable for the reliable detection of traces of ricinoleic acid.
use
The zinc salt of ricinoleic acid (English: Zinc Ricinoleate) is used as a deodorant additive in deodorants and as an odor binder in creams, lotions and foot care products. In deodorants, it does not inhibit natural perspiration, but the foul-smelling odorous substances that result from the bacterial decomposition of sweat are coated, bound and therefore no longer perceived as unpleasant.
Ricinoleic acid is responsible for the effects of castor oil , which as a laxative (laxative) and in obstetrics as a so-called labor cocktail to be given birth pangs trigger. In both cases the acid acts on prostaglandin receptors .
Hydrogenation of the double bond gives 12-hydroxystearic acid (12-hydroxyoctadecanoic acid), which is used on a large scale for the production of soap thickeners for lubricating greases.
Individual evidence
- ↑ Entry on RICINOLEIC ACID in the CosIng database of the EU Commission, accessed on May 26, 2020.
- ↑ a b c d e Entry on ricinoleic acid. In: Römpp Online . Georg Thieme Verlag, accessed on November 11, 2014.
- ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-296.
- ↑ a b Data sheet ricinoleic acid from Sigma-Aldrich , accessed on April 22, 2011 ( PDF ).
- ↑ 9-Octadecenoic acid, 12-hydroxy- at PlantFA Database, accessed October 29, 2017.
- ↑ AT James, HC Hadaway, JP Webb: The Biosynthesis of Ricinoleic Acid. In: Biochem J. 95, May 1965, pp. 448-452. PMID 14340094
- ↑ C. Franzmann, J. Wächter, N. Dittmer, HU Humpf: Ricinoleic acid as a marker for ergot impurities in rye and rye products. In: J Agric Food Chem. 58 (7), Apr 14, 2010, pp. 4223-4229. PMID 20297816
- ↑ RW Walenga, S. Boone, MJ Stuart: Analysis of blood HETE levels by selected ion monitoring with ricinoleic acid as the internal standard. In: Prostaglandins. 34 (5), Nov 1987, pp. 733-748. PMID 3432563
- ↑ K. Yamamoto, A. Kinoshita, A. Shibahara: Ricinoleic acid in common vegetable oils and oil seeds. In: Lipids. 43 (5), May 2008, pp. 457-460. PMID 18288512
- ↑ Antje Findeklee: The effect of castor oil on the labor force has been clarified. at: Spektrum.de , May 21, 2012.
- ↑ Sorin Tunaru, Till F. Althoff, Rolf M. Nüsing, Martin Diener, Stefan Offermanns: Castor oil induces laxation and uterine contraction via ricinoleic acid activating prostaglandin EP 3 receptors. In: Proc. Natl. Acad. Sci. April 25, 2012, doi: 10.1073 / pnas.1201627109 .
