Margaric acid

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Structural formula
Structural formula of margaric acid
General
Surname Margaric acid
other names
  • Heptadecanoic acid
  • n -Heptadecanoic acid
  • Daturic acid
Molecular formula C 17 H 34 O 2
Brief description

colorless leaflets

External identifiers / databases
CAS number 506-12-7
EC number 208-027-1
ECHA InfoCard 100.007.298
PubChem 10465
Wikidata Q902204
properties
Molar mass 270.45 g mol −1
Physical state

firmly

density

0.8532 (60 ° C)

Melting point

59-61.1 ° C

boiling point

227 ° C (at 13.3 kPa), 364 ° C

solubility
  • practically insoluble in water
  • slightly soluble in alcohol
  • soluble in ether, chloroform and acetone
Refractive index

1.4342 (60 ° C)

safety instructions
GHS labeling of hazardous substances
07 - Warning

Caution

H and P phrases H: 315-319
P: 302 + 352-280-305 + 351 + 338
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

The margaric acid (from French acid margarique from Greek μάργαρον, márgaron or μαργαρίτης, margarítēs "pearl"), according to IUPAC n -heptadecanoic acid, belongs to the group of alkanoic acids . It is a saturated fatty acid with an odd number of 17 carbon atoms. Their salts and esters are systematically called heptadecanoates .

history

This compound got its name from the French chemist Michel Eugène Chevreul . When investigating the saponification of lard with potash in 1814, he believed that he had discovered a new fatty acid. He named this compound, which was in the form of pearly shimmering crystals , based on the Greek word márgaron (“pearl”), as acid margarique (hence the word oléomargarine “ margarine ”).

In addition to oleic acid , margaric acid was examined more closely by the German chemist Franz Varrentrapp during his doctorate with Justus von Liebig . Liebig also mentioned margaric acid several times in his "Chemical Letters". He writes about her in the 19th letter:

“So when Innocent's churchyard was moved from the interior of the city to the gates of Paris, most of the corpses were apparently turned into fat. The substance of the skin, muscles, cells and sinews had completely disappeared down to the bones, only the fat of the corpses, which had resisted decomposition the longest, was left as margaric acid, of which hundreds of cents were then processed into lights and soap by the soap makers in Paris . "

However, by developing new separation methods, Wilhelm Heinrich Heintz discovered that the natural compound previously described as margaric acid was not a pure substance , but a mixture of palmitic and stearic acid . At the same time, Heintz succeeded in synthesizing margaric acid.

Occurrence

For a long time it was assumed that margaric acid does not occur naturally, since only fatty acids with an even carbon number could be isolated. This presumption was refuted in 1957 when margaric acid was isolated from butterfat . However, it occurs naturally in various lipids of many plant species, mostly only in low concentration, it can also be found in milk fat and animal fat , in cattle sebum and pork lard it is about 2% by weight.

Extraction and presentation

Probably the first description of the synthesis of margaric acid in the laboratory dates back to 1958.

pharmacology

A comparatively high proportion of margaric acid , like pentadecanoic acid , in the phospholipids of the blood plasma - a marker for a high consumption of high-fat milk products - is associated with a lower risk of developing type 2 diabetes mellitus in observational studies .

Individual evidence

  1. ↑ a b c d e data sheet margaric acid at Acros, accessed on June 10, 2016.
  2. ↑ a b c d e f David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 96th edition. (Internet version:), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-288.
  3. ↑ Entry on margaric acid. In: Römpp Online . Georg Thieme Verlag, accessed on July 4, 2018.
  4. ↑ Article margarin in the Online Etymology Dictionary
  5. ^ Chemical letters from Justus von Liebig, sixth edition, 1878.
  6. ↑ RP Hansen, FB Shorland, N. June Cooke: Occurence in Butterfat of n-Heptadecanoic Acid (margaric acid). In: Nature . 179 (98), 1957, p. 98, doi : 10.1038 / 179098a0 ; PMID 13400103 .
  7. ↑ Heptadecanoic acid at PlantFA Database, accessed November 6, 2017.
  8. ↑ HP Kaufmann, W. Stamm: The synthesis of long-chain fatty acids II. Straight-chain alkanoic acids. In: Chemical Reports . 91 (10), 1958, pp. 2121-2126 doi : 10.1002 / cber.19580911018 .
  9. ↑ NZ Herald News : Slice of good news for cheese lovers , August 7, 2014.

Web links

Wiktionary: margaric acid  - explanations of meanings, word origins, synonyms, translations