Pectic acid arabinose units

Arabinans, minor lateral branches of acid pectic substances, consist of short arabinose chains, bonded in a-(l,5), with ramifications of individual arabinose units on C3 (Figure 3.20). 

The most abundant hemicelluloses in cotton are pectic substances. Those in wood consist of relatively short heteropolymers of glucose, xylose, galactose, mannose, and arabinose, as well as uronic acids of glucose and galactose. These monosaccharide units and derivatives are linked together by 1 3, 1 6, and 1 -> 4 glycosidic bonds. Most are... 

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