Galactomannans fine structure

Although a considerable amount of effort has gone into the determination of the fine structure of galactomannans, a complete structure has not yet been established. 

Gleditsia gums. This would indicate significant differences in fine structure for these galactomannans. 

Interest in the genetic engineering of both plants and micro-organisms for the production of tailor made amylose, amylopectin and/or starches has also been reported. Furthermore, investigations on the enzymatic modification of starch and its major components, for example the introduction of additional branches composed of glucose and/or other monosaccharides and/or uronic acids as well as amino acids or peptides, to produce carbohydrates of possibly comparable functionality to galactomannans, pectin, gum arable, etc., has been initiated. Also studies on the metabolic fate of carbohydrates in food, the biosynthesis of starch, the fine structure of starch from different sources, the effect of electrolytes on the gelatinization of starch and the development of enzymic methods for starch analyses are still active. 

Details of a number of established chemical methods used in determining various aspects of the fine structures of polysaccharides-for example, the specific degradation of polysaccharides containing uronic acid residues by base-catalysed elimination, the location of acyl substituents, and the distribution of singleunit side-chains of D-galactose in galactomannans by alkaline hydrolysis of 6-deoxy-6-(4-tolylsulphonyl)hexopyranosides -are reported in the latest volume in the series Methods in Carbohydrate Chemistry . 

Edwards, M.E. et ah, The seeds of Lotus japonicus fines transformed with sense, antisense, and sense/ antisense galactomannan galactosyltransferase constructs have structurally altered galactomannans in their endosperm cell walls, Plant Physiol, 134,1153, 2004. 

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