Galactomannans carob

Carob galactomannan. See Galactomannan Carob gum. See Locust bean (Ceratonia siliqua) gum... 

Assay and Purification of p-Mannanases. p-Mannanase can be specifically measured in crude enzyme mixtures with a dye-labelled carob galactomannan substrate (6), This substrate has a galactose content high enough (23%) to impart solubility to the substrate, but sufficiently low as not to interfere with the action of p-mannanases on the D-mannan backbone. The soluble dye-labelled substrate is incubated with enzyme preparation under controlled conditions and the reaction is terminated and unreacted dyed polysaccharide precipitated by ethanol addition. 

Table I. Oligosaccharides produced on hydrolysis of carob galactomannan by p-mannanases...

Like guaran, and the endosperm polysaccharides of other legumes, locust bean (carob)gum [900040-2] is also a galactomannan. Like guaran, it has a linear backbone of (1 — 4)-linked p-D-mannopyranosyl units. However, in locust bean gum, approximately one of every 3.9 p-D-mannopyranosyl units, on the average, is substituted with an a-D-galactopyranosyl unit attached at 0-6. 

In hot-water-soluble, carob galactomannan, the relatively high level of couplets of neighboring D-galactosyl groups would reflect a capacity for a repeat substitution on the opposite side of the mannan chain, once the steric hindrance involved in formation of the enzyme-substrate complex has been... 

Fio. 3.—Fractions of the D-Mannan Chain of Hot-water-soluble Carob Galactomannan (18% Content of D-Galactose) that Occur as Unsubstituted and Substituted D-Mannosyl... 

A way of reconciling the observed proportions of mannobi-, tri-, and tetra-oses and heterosaccharides,16113 released by guar-seed jS-D-mannanase (from hot-water-soluble carob galactomannan), with this model, would be if the enzyme preferentially hydrolyzes appropriate, unsubstituted d-mannosyl residues (as in 31) then, it would only be able to hydrolyze on the reducing side of a substituted D-mannose (as in 32) if there were a... 

Dimethyl-D-mannose has been isolated from the hydrolysis products of the methylated galactomannans from carob seed gum14-18 and from guar gum,16 17 and also from mannocarolose,8t 18 a polysaccharide synthesized by Penicillium charlesii G. Smith. The synthesis of this sugar, which has not been obtained crystalline, has been accom-... 

The polysaccharidic galactomannans which occur94 in the endosperms of guar, locust bean, carob bean, and many other legumes have been... 

Turquois, T., Rochas, C., and Taravel, F. R. (1992). Rheological studies of synergistic kappa carrageenan-carob galactomannan gels. Carbohydr. Polym. 17 263-268. 

Locust bean or carob Thickener exhibits Galactomannan Endosperm of locust... 

Turquois, T, Taravel, F. R, and Rochas, C. 1993. Synergy of the agarose-carob galactomannan blend inferred from mnr and rheological studies. Carbohydr. Res. 238 27-38. 

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