Laminarin

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Structural formula
Laminarin
Typical section from the polysaccharide chain with one branch
General
Surname Laminarin
other names

Laminaran

CAS number 9008-22-4
Monomers / partial structures Laminaribiosis
PubChem 46173707
Brief description

beige powder

properties
Physical state

firmly

solubility

water soluble and water insoluble form

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 .

Laminarin is a chemical compound that occurs frequently in nature . It is a to the (1 → 3) -β- D - glucans belonging depending on the form of water-soluble polysaccharide . In its polymerized form, it serves algae , especially brown algae and diatoms, as an energy store, similar to the starch in land plants.

construction

The main chain of laminarin is branched in an irregular sequence, with another glucose molecule being β- (1 → 6) -linked. The ratio of β- (1 → 3) and β- (1 → 6) -glycosidically linked glucose molecules is 15: 1. Other sources report a degree of branching of 3: 1.

Both soluble ( Laminaria digitata ) and water-insoluble forms ( Laminaria cloustoni and Laminaria hyperborea ) have been found in various types of brown algae . The degree of branching determines whether the compound is water soluble; the little branched laminarin is soluble. The water-soluble form consists of 23-25 ​​glucose units. For every 37 (water-soluble form) or 57 (water-insoluble form) glucose units, the reducing chain end is glycosidically masked with one molecule of mannitol .

The dimer of two glucose units that are (1 → 3) -β-linked is the laminaribiose .

Extraction

Laminarin is obtained in large quantities from the fingertip ( Laminaria digitata ).

Use and biological importance

In animals, laminarin generates a response from the respective immune system. Like many algae polysaccharides, sulfated laminarines are potent anticoagulants . Laminarin was also previously used as a drug to treat nervous disorders.

In brown algae, laminarin is a reserve carbohydrate with a similar function to the starch in land plants or the glycogen in animals. The enzyme laminarinase ( endo -1,3 (4) -β-glucanase) breaks down polysaccharides with β-1,3- and β-1,4- glycosidically linked glucose building blocks.

Individual evidence

  1. ↑ a b c Datasheet Laminarin from Laminaria digitata at Sigma-Aldrich , accessed on October 17, 2016 ( PDF ).
  2. ↑ a b c J.B. Harborne, H. Baxter: Phytochemical Dictionary: A Handbook of Bioactive Compounds from Plants , 1999, CRC Press , ISBN 0-7484-0620-4 .
  3. ^ PM Collins: Dictionary of carbohydrates with CD-ROM. 2nd edition, CRC Press, 2006, ISBN 978-0-8493-3829-8 , p. 679.
  4. ↑ a b c Rudolf Hansel, Otto Sticher: Pharmakognosie. Phytopharmazie 9th edition, Springer, 2009, ISBN 978-3-642-00962-4 , pp. 570-571.
  5. ^ A. Beattie, EL Hirst, E. Percival: Studies on the metabolism of the Chrysophyceae. Comparative structural investigations on leucosine (chrysolaminarin) separated from diatoms and laminarin from the brown algae. In: The Biochemical journal. Volume 79, June 1961, pp. 531-537, PMID 13688276 . PMC 1205682 (free full text).
  6. ↑ Nisizawa K, Yamaguchi T, Handa N, Maeda M, Yamazaki H: Chemical nature of a uronic acid-containing polysaccharide in the peritrophic membrane of the silkworm . In: Oxford University Press for Japanese Biochemical Society (Ed.): Journal of Biochemistry . 54, Japan, November 1963, pp. 419-426. PMID 14089735 .
  7. ^ Waldemar Ternes: Food Lexicon. 4th edition, Behr's Verlag, 2005, ISBN 978-3-89947-165-6 , p. 1033.
  8. ↑ R. Hegnauer: Chemotaxonomy of Plants: Volume 1: Thallophyten, Bryophyten, Pteridophyten und Gymnospermen. Birkhäuser, 1962, ISBN 978-3-7643-0164-4 , p. 60.
  9. ↑ KH Kim et al .: Anti-apoptotic activity of laminarin polysaccharides and their enzymatically hydrolyzed oligosaccharides from Laminaria japonica. In: Biotechnology letters. Volume 28, Number 6, March 2006, pp. 439-446, doi: 10.1007 / s10529-005-6177-9 . PMID 16614911 .
  10. ↑ M. Shanmugan and KH Mody: Heparinoid-active sulphated polysaccharides from marine algae as potential blood anticoagulant agents. Current Science 79/12/ 2000 p 1672-1683; Online version ( Memento of the original from August 18, 2005 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 129 kB). @1@ 2Template: Webachiv / IABot / tejas.serc.iisc.ernet.in
  11. ↑ H.-D. Belitz, W. Grosch, P. Schieberle: Textbook of food chemistry. 6th edition, 2007, Springer, ISBN 978-3-540-73201-3 , p. 341.