Arabinogalactans chemical structure

Kg. 24. Partial chemical structure of some hemicelluloses A — 0-acetyl-(4-0-methyl-glucurono)xylan from hardwood B = arabino-(4-0-methylglucurono)xylan from softwood C = 0-acetyl-galactoglucomannan D = arabinogalactan from larch wood (138). 

Arabinogalactans form a family of polysaccharides with a branched framework made up predominately of (l- 3)-linked jff-D-galactopyranosyl units with varying amounts of (1 6)-linked )ff-D-galactopyranosyl units. Their structures are often complex, with an apparent random distribution of side chains in at least some. They often occur as a mixture of components that differ widely in both molecular weight and chemical structure. 

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