Homoglycans or homopolysaccharides are in contrast to the heteroglycans polysaccharides composed of similar monosaccharides, ie polysaccharides assembled from a single variety of simple sugars. The biochemically important homoglycans are glycogen (own synthesis, meat), and starch ( corn ), and cellulose ( as a dietary fiber, grass, lettuce) from plants and chitin as scaffold material in arthropods and fungi.
Glycogen is composed of Maltosedisacchariden, location is the main muscle. Starch is broken down into the unbranched amylose and the branched amylopectin. The amylose, which accounts for about 20%, consisting of alpha -1-4 -linked, non- branched glucose. The primary structure is a helix, by Iodeinlagerung the color changes to blue. This is the amylose and thus Detection of starch. It is broken down in the digestive tract first in disaccharide ( maltose ). The amylopectin has an average of about 25 glucose molecules branching to. The concatenation is done via α -1-4 bonds, branches by a α -1 -6- side chain with isomaltose as a basic element.
Cellulose, however, is the β -1-4 linked, and therefore can not be degraded by the human organism as a macromolecule.
Homoglycans occur naturally found in almost all living things and form scaffold ( chitin, cellulose) and storage compounds (starch, glycogen).
- Curdlan from Alcaligenes faecalis var myxogenes
- Dextran from Leuconostoc mesenteroides, Leuconostoc and Lactobacillus dextranicum hilgardii
- Sinorhizobium meliloti from Glucuronan
- Lentinan from Lentinus elodes
- Levan from Alcaligenes viscosus, Zymomonas mobilis and Bacillus subtilis
- Mutants of Streptococcus mutans
- Pullulan from Aureobasidium pullulans
- Scleroglucan from Sclerotium rolfsii, Sclerotium delphinii and Sclerotium glucanicum
- Schizophyllan from Schizophyllum commune
- Cellulose from plants and Acetobacter xylinum
- Chitosan from Mucorales
- Chitin from various fungi and arthropods
- Pleuran from Pleurotus ostreatus
- Zymosan from yeasts