Galactomannans isolation

As with most polysaccharides, galactomannans isolated chemically may be heterogeneous and polydisperse with respect to both... 

Constit. of the galactomannan isol. from the cells of Trypanosoma cruzi, the causative agent of chagas disease. 

Repeating unit in plant galactomannans. Isol. from partial acid hydrolysates of lucerne Medicago saliva), fenugreek (Trigonella foenum-graecum). Palmyra pahn nut Borassus flabellifer), spruce-... 

Immunochemical studies on galactomannans isolated from the mycelia and culture media of Hormodendrum pedrosoi, H. compactum, and H. dermatitidis have indicated that acid-labile D-galactofuranosyl residues are responsible for precipitating antibodies. The galactomannans and their respective core components precipitated anti-(5. cerevisiae) serum, which interacts only with (1 6)-... 

Baron M, Gorin PAJ, lacomini M (1989) Structural studies on a galactomannan isolated from the lichen Stereocaulon ramulosum. Agric Biol Chem 53 1751-1758... 

A galactomannan isolated from the leaves of Symplocos spicata contains residues of L-arabinose and D-galactose (5 3). Methylation and periodate-oxidation studies suggested that this polysaccharide has an unusual structure the main chain is composed of (1 4)-linked jS-L-arabinopyranosyl and (1 3)-... 

A method for purifying certain neutral polysaccharides by precipitation in borate buffer with cetyltrimethylammonium bromide was developed by Stacey and coworkers,118 but it does not appear to have been used for the isolation of galactomannan gums. It has, however, been claimed119 that guar gum and locust-bean gum can be separated by carefully controlled precipitation of the cetylpyridinium bromide complexes by 0.1 M sodium hydroxide. Guar gum is precipitated between pH 7.0 and 8.3, and locust-bean gum between 8.6 and 9.3. 

In a similar series of experiments, Unrau and Choy59 found that the structure of Caesalpinia pulcherima galactomannan differs from the normal type of structure, but to a much lesser extent —4% of the D-mannose units in the main chain are /3-D-(l — 3)-linked, and 2% are ( 1 — 2)-linked. Smith degradation again indicated that isolated and consecutive /8-D-(l — 3)-linkages were present in the main chain. 

The disaccharide epimelibiose [0-a-D-galactopyranosyl-(l— 6)-D-mannopyranose] was first isolated by Whistler and Durso202 from a partial hydrolyzate of the D-galactomannan of guar by acid (see also, Ref. 203), and they also elucidated its structure. This disaccharide constitutes the branch points of the main D-galactomannan chain (see Section V,3). 

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-... 

A highly branched, acidic galactomannan was isolated from the oak lichen Evemia prunastri by extraction with cold alkali, followed by successive purification steps with barium hydroxide and Fehling solutions. The polysaccharide contained nonreducing end-units of galac-topyranose, mannopyranose, and glucopyranosyluronic acid, with 2-O-, 2,6-di-O-, 3-6-di-O-, and 2,3,6-tri-O-substituted mannopyranosyl... 

Reid and Meier201 found that the breakdown of galactomannan in isolated, fenugreek endosperms is strongly inhibited by cycloheximide... 

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