Galactomannans

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Galactomannans (or galactomannans ) are starch- like substances made from branched carbohydrate chains. The main chain consists of mannose , with short side chains of one galactose molecule each occurring at various intervals .

structure

The main chain of the polysaccharide consists of D- mannose units, which, analogous to the amylose of starch, form a helical screw structure . The monomers are only linked β-1,4-glycosidically . Side chains from individual galactose molecules appear at irregular intervals; these are α-6,1-glycosidically bound to mannose.

Occurrence and meaning

The main component of the guar bean , from which the thickener guar gum is made, is a galactomannan. Carob gum from the carob tree Ceratonia siliqua also contains the galactomannan " Carubin ".

Galactomannans are also found in the Aspergillus cell wall and can be found in the blood of patients with invasive aspergillosis . Among other things, an ELISA test is available for the detection of galactomannans, in order to detect an infection with Aspergillus as early as possible in patients with immunosuppression .

The devil's tongue Amorphophallus konjac supplies the food additive " Konjak " (E 425), which primarily contains glucomannans and little or no galactomannans.

Individual evidence

  1. ↑ a b c Wissenschaft-Online-Lexika: Entry on galactomannans in the Lexicon of Nutrition , accessed on May 14, 2009.
  2. ↑ E. Reiss E, PF Lehmann: Galactomannan antigenemia in invasive aspergillosis. In: Infection and Immunity . 1979 Jul; 25 (1): 357-65, PMID 383620 .
  3. ↑ JP Latgé, H. Kobayashi, JP Debeaupuis, M. Diaquin, J. Sarfati, JM Wieruszeski, E. Parra, JP Bouchara, B. Fournet: Chemical and immunological characterization of the extracellular galactomannan of Aspergillus fumigatus. Infect Immune. 1994 December; 62 (12): 5424-5433, PMID 7960122 , PMC 303284 (free full text).
  4. ↑ JM Scotter, P. Campbell, TP Anderson, DR Murdoch, ST Chambers, WN Patton: Comparison of PCR-ELISA and galactomannan detection for the diagnosis of invasive aspergillosis. In: Pathology , 2005 Jun; 37 (3): 246-53, PMID 16175901 .