Galactomannan, of carob

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

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-... 

C18H32O16 504.441 Isol. from partial acid hydrolysates of Cassia tora, lucerne (Medicago sativa) and from the galactomannan of Leucaena leucocephala from enzymatic hydrolysates of guar (Cyamopsis tetragonoloba), carob (Ceratonia siliqua) galactomannans. 

Fig. 6.5. (A) Depletion of galactomannan in carob (x), lucerne ( ) and soybean (o). Redrawn from McCleary and Matheson, 1976 [99]. (B) Differences between the amounts of galactose and mannose released and accumulated during hydrolysis of galactomannan...

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. 

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. 

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