Docosahexaenoic acid

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Structural formula
Structural formula of docosahexaenoic acid
General
Surname Docosahexaenoic acid
other names
  • DHA (Docosahexaenoic acid)
  • (4 Z , 7 Z , 10 Z , 13 Z , 16 Z , 19 Z ) -Docosa-4,7,10,13,16,19-hexaenoic acid
  • ( all - Z ) -Docosa-4,7,10,13,16,19-hexaenoic acid
  • Cervonic acid
  • Clupanodonic acid
  • 22: 6 (ω − 3) ( lipid name )
Molecular formula C 22 H 32 O 2
Brief description

light yellow liquid

External identifiers / databases
CAS number 6217-54-5
EC number 612-950-9
ECHA InfoCard 100.118.398
PubChem 445580
ChemSpider 393183
DrugBank DB03756
Wikidata Q423345
properties
Molar mass 328.49 g mol −1
Physical state

liquid

density

0.95 g cm −3

Melting point

−44 ° C

safety instructions
GHS labeling of hazardous substances
no GHS pictograms
H and P phrases H: no H-phrases
P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Docosahexaenoic acid ( DHA ) is a polyunsaturated fatty acid . It belongs to the class of omega-3 fatty acids .

Occurrence

Ready-to-cook salmon, cut as a steak

Docosahexaenoic acid is produced by phototrophic and heterotrophic marine microalgae . It occurs in high concentrations in the species Ulkenia , Pavlova and in the heterotrophic species Schizochytrium . They form the basis for the provision of DHA in the marine food chain. For this reason, fatty sea fish such as salmon ( Salmo salar ) or Atlantic herring ( Clupea harengus ) are most frequently named as a food source for eicosapentaenoic acid (EPA) and DHA. About fish and especially fish meal , fish oil and blubber it enters last into the human food.

Humans synthesize DHA from α-linolenic acid (ALA), which is therefore classified as essential . Studies show that around 5–10% of the ingested α-linolenic acid is converted into EPA and 2–5% into DHA. Other studies speak of conversion rates to EPA and DHA less than 5%. One study comes to the conclusion that the conversion rate of ALA to DHA in infants is 1% and in adults it is less than 1%. According to the International Society for the Study of Fatty Acids and Lipids (ISSFAL), increasing the DHA level in the blood by supplementing additional ALA, EPA or other precursors is not possible. Barcel-Coblijn & Murphy come to the conclusion that the body can produce sufficient DHA if enough α-linolenic acid (> 1200 mg) is consumed per day. A 2016 review examining ALA to DHA conversion rates concluded that ALA is an unsuitable replacement for DHA.

However, it also occurs in small amounts in a few plant species.

properties

Docosahexaenoic acid is a colorless oily liquid. The six double bonds are in the cis form . It is a so-called polyenoic acid and an isolenic acid because the double bonds are separated by a methylene group . It has a very low melting point of −44 ° C.

Analytics

For the reliable qualitative and quantitative determination of docosahexaenoic acid, after appropriate sample preparation, the coupling of gas chromatography , preferably using capillary columns, with mass spectrometry is suitable . Using mass spectrometry, specific questions about the natural or synthetic origin of docosahexaenoic acid can also be answered.

Biological function

Docosahexaenoic acid has important metabolic functions. As a fatty acid component of phospholipids , it is an integral part of membranes , especially nerve cells . Docosahexaenoic acid is particularly found in the brain and retina : up to 97 percent of the omega-3 fatty acids in the brain and up to 93 percent of the omega-3 fatty acids in the retina consist of DHA. Unlike EPA , DHA can lower blood pressure and heart rate. DHA is the starting material for the biosynthesis of docosatrienes , resolvins and neuroprotectins (so-called docosanoids ).

Their biosynthesis in the animal organism is based on the essential omega-3 fatty acid α-linolenic acid via EPA, which is also important for the metabolism. Age, illness and stress as well as an excessive intake of omega-6 fatty acids ( corn oil , sunflower oil , etc.) also impair the conversion into docosahexaenoic acid, e.g. B. if you sear the fish in sunflower oil. The amount consumed therefore also depends on the preparation. Regular consumption of fatty sea fish, for example, which is best steamed, baked or fried in fats low in omega-6 fatty acids, improves the supply of these omega-3 fatty acids.

The tissues in the human body that synthesize docosahexaenoic acid include the mammary glands (breasts). DHA is contained in breast milk , but not in cow's milk, which may be a peculiarity of the human species: The infant receives additional docosahexaenoic acid through breast milk to build the relatively large human brain in contrast to the amount that the infant's liver can synthesize itself.

Recent studies from Italy have shown that the sperm quality seems to go hand in hand with the docosahexaenoic acid content. The determination of the docosahexaenoic acid content could therefore usefully supplement the statements of a spermiogram .

Nutritional supplement

Since the intake of omega-3 fatty acids and especially docosahexaenoic acid in Europe is well below the recommendations, DHA has been offered in the form of capsules and foods fortified with docosahexaenoic acid for several years. For the production of docosahexaenoic acid there are two currently used industrially: the processing of fish oils from fish waste of oily sea fish and the biotechnological extraction by breeding docosahexaenoic acid-forming microalgae (schizochytrium and ulkenia). Fish can produce these fatty acids themselves. The short-chain omega-3 fatty acids ingested are metabolized by desaturases and elongases to docosahexaenoic acid. In addition to the capacity of the fish cells to synthesize the fatty acids themselves, they also accumulate docosahexaenoic acid by absorbing docosahexaenoic acid-containing microalgae and plankton .

An expert commission set up by the EU advises pregnant women to consume at least 200 mg DHA per day, which is said to have a positive effect on the development of the eye and brain functions of the unborn child. A sufficient supply of DHA is also advised, especially in the first two years of life. Meanwhile, some manufacturers of baby food are also adding fish oil to their products to meet the needs of babies for omega-3 fatty acids, which are naturally present in breast milk.

Individual evidence

  1. ^ A b John W. Blunt, Murray HG Munro: Dictionary of Marine Natural Products. Chapman & Hall, 2008, ISBN 978-08493-8216-1 , pp. 701 f.
  2. ↑ HM Rauen: Biochemical Pocket Book. Springer, 1956, ISBN 978-3-642-53241-2 (reprint), p. 232.
  3. ↑ a b c d e data sheet cis-4,7,10,13,16,19-Docosahexaenoic acid, ≥98% from Sigma-Aldrich , accessed on December 19, 2019 ( PDF ).
  4. ↑ a b J. T. Brenna, N. Salem, AJ Sinclair, SC Cunnane: alpha-Linolenic acid supplementation and conversion to n-3 long-chain polyunsaturated fatty acids in humans. In: Prostaglandins, leukotriene, and essential fatty acids. Volume 80, number 2-3, 2009, pp. 85-91, ISSN  0952-3278 , doi: 10.1016 / j.plefa.2009.01.004 , PMID 19269799 .
  5. ↑ Breanne M. Anderson, David WL Ma: Are all n-3 polyunsaturated fatty acids created equal? In: Lipids in Health and Disease. 8, 2009, p. 33, doi: 10.1186 / 1476-511X-8-33 .
  6. ↑ JT Brenna: Efficiency of conversion of alpha-linolenic acid to long chain n-3 fatty acids in man. In: Current opinion in clinical nutrition and metabolic care. Volume 5, Number 2, 2002, pp. 127-132, ISSN  1363-1950 , PMID 11844977 .
  7. ↑ Gwendolyn Barcel-Coblijn, Eric J. Murphy: Alpha-linolenic acid and its conversion to longer chain n-3 fatty acids: Benefits for human health and a role in maintaining tissue n-3 fatty acid levels. In: Progress in Lipid Research. 48, 2009, pp. 355-374, doi: 10.1016 / j.plipres.2009.07.002 .
  8. ↑ EJ Baker, EA Miles, GC Burdge, P. Yaqoob, PC Calder: Metabolism and functional effects of plant-derived omega-3 fatty acids in humans. In: Progress in lipid research. Volume 64, 2016, pp. 30-56, doi: 10.1016 / j.plipres.2016.07.002 , PMID 27496755 (review).
  9. ↑ 4,7,10,13,16,19-Docosahexaenoic acid from PlantFA Database, accessed October 30, 2017.
  10. ^ T. Yi, SM Li, JY Fan et al .: Comparative analysis of EPA and DHA in fish oil nutritional capsules by GC-MS. In: Lipids Health Dis. 13, 2014, 190, PMID 25496531 .
  11. Jump up ↑ J. Wang, D. Wang, H. Zhang et al .: Analysis of docosahexenoic acid in human blood using heterocyclic derivatization-gas chromatography-triple quadrupole mass spectrometry. In: Se Pu. 31 (8), 2013, 734-8, PMID 24369605 , (Chinese).
  12. ^ Y. Schober, HG Wahl, H. Renz, WA Nockher: Determination of red blood cell fatty acid profiles: Rapid and high-confident analysis by chemical ionization-gas chromatography-tandem mass spectrometry. In: J. Chromatogr. B analyte. Technol. Biomed Life Sci. 1040, 2017, 1-7, PMID 27880928 .
  13. ↑ RJS Lacombe, V. Giuliano, SM Colombo et al .: Compound-specific isotope analysis resolves the dietary origin of docosahexaenoic acid in the mouse brain. In: J. Lipid Res. 58 (10), 2017, 2071-2081, PMID 28694298 .
  14. ↑ TA Mori, DQ Bao, V. Burke, IB Puddey, LJ Beilin: Docosahexaenoic acid but not eicosapentaenoic acid lowers ambulatory blood pressure and heart rate in humans. In: Hypertension. 34 (2), 1999, pp. 253-60, PMID 10454450 .
  15. ↑ Michael Lukas: Mutiny at Captain Iglo. Report at DocCheck.com from January 13, 2010.
  16. ↑ C. Zerbinati, L. Caponecchia, R. Rago et al .: Fatty acids profiling reveals potential candidate markers of semen quality. In: Andrology. 4 (6), 2016, 1094-1101, PMID 27673576 .
  17. ↑ Algae Oil: New type of oil made from marine microalgae. Retrieved September 12, 2017 .
  18. ↑ Pahrmiweb.com: New EU Recommendation Suggests Pregnant Women Need Higher Levels of Omega-3. Perinatal Lipid Nutrition group (PeriLip) ( Memento of the original from December 15, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. on pharmiweb.com, August 29, 2007. @1@ 2Template: Webachiv / IABot / www.pharmiweb.com
  19. ↑ toilet Heird: The role of polyunsaturated fatty acids in preterm infants and term and breastfeeding mothers. In: Pediatr. Clin. North Am. 48 (1), 2001, pp. 173-188, PMID 11236724 .
  20. ↑ HiPP BIO Combiotik® initial milk contents . Website manufacturer Hipp. Retrieved November 26, 2014.

literature

Web links