Galactomannans biosynthesis

The amount of substitution, and tendencies in the pattern of substitution, of galactomannans can be related to possible effects in the biosynthesis.116... 

The details of the metabolism of plant polysaccharides that contain a-D-galactopyranosyl residues are limited to D-galactomannans.12 However, published data on the exact mechanism of biosynthesis are still not available. 

It has been suggested that a similar mechanism of D-galactosyl transfer may be involved in the biosynthesis of galactomannan, with the participation of GDP-D-mannose.143,146 Courtois and coworkers145 have, in fact, detected UDP-D-galactose and GDP-D-mannose in fenugreek seeds. 

Mohnen D (1999) Biosynthesis of pectins and galactomannans. In Pinto BM (ed) Carbohydrates and their derivatives including tannins, cellulose, and related lignins, vol 3, Comprehensive natural products chemistry. Elsevier, Amsterdam, chap 3.15... 

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. 

---