[Study of galactoglucomannans from the seed of Cercis canadensis L].

Galactoglucomannans were isolated by selective precipitation from aqueous and alkaline extracts of endosperm and hulls of Cercis canadensis, a member of the family Fabaceae. Their monosaccharide composition (Man: Gal: Glu) was as follows: 10.4: 0.9: 1 (polysaccharide from the endosperm) and 4.5: 0.9: 1 (polysaccharide from the hulls). The identity of IR spectra was indicative of the commonness of their structure. Analysis of the structure of the galactoglucomannan from endosperm by 13C NMR spectroscopy showed that its main chain consisted of 1,4-beta-D-manno- and 1,4-beta-D-glucopyranose. Part of mannose residues in the chain were substituted at C6 with single residues of alpha-D-galactopyranose. Galactoglucomannans are located in different part of the seed and implement different functions.

[Galactomannan from ambiguous Crazyweed (Oxytropis ambigua (Pall) DC)]. / Galaktomannan ostrolodochnika skhodnogo (Oxytrophis ambigua (Pall) DC).

A galactomannan with a molecular weight of 735 kDa was first isolated and purified from seeds of ambiguous crazyweed Oxytropis ambigua (Pall) DC. (family Leguminosae) with a yield of 3.6%. Its aqueous solutions displayed an optical activity ([alpha]D = 73.32 degrees) and high viscosity ([eta] = 644 ml g-1). Chemical analysis and 13C-NMR spectroscopy revealed the presence in the heteropolysaccharide of D-mannopyranose and D-glucopyranose at a molar ratio of 1.39:1. The linear backbone of its macromolecule consists of 1.4-beta-D-mannopyranose residues. Single beta-D-galactose residues substitute 72% of mannoses to form branches.

[Composition and structure of a galactomannan macromolecules from seeds of Astragalus lehmannianus Bunge]. / Sostav i struktura makromolekuly galaktomannana semian Astragalus lehmannianus Bunge.

The composition and structure of a galactomannan from seeds of Astragalus lehmannianus, an endemic legume species, is reported for the first time. The purified galactomannan (yield, 4.8%) contained 55% D-mannose and 45% D-galactose and had a molecular weight of 997.03 kDa. Its aqueous solutions were optically active and highly viscous (the specific rotation, [alpha]D, equaled +81.3 degrees; the characteristic viscosity, [eta], 868.4 ml/g). Chemical, chromatographic, and spectral (IR and 13C-NMR spectroscopy) methods were used to demonstrate that the main chain of the molecule is formed by residues of 1,4-beta-D-mannopyranose, 78% of which are substituted at position 6 with single alpha-D-galactopyranose. The distribution of galactose along the chain was calculated from NMR spectra: frequencies of occurrence, per pair of neighboring mannose units, of (1) two substituents, (2) one substituent, and (3) no substituents were 65.3, 31.5, and 3.2%, respectively. The specific rotation of galactomannans was shown to correlate with their content of galactose.