[Composition and structure of galactomannan from the seed of Gleditsia ferox Desf].
Galactomannan, a heteropolysaccharide with a molecular weight of 1660 kDa, was isolated form the seed of Gleditsia ferox Desf., introduced in Russia, with a yield of 18.9%. Its aqueous solutions were optically active ([alpha]D = +30.5 degrees) and highly viscous ([eta] = 1430 ml/g). Analysis of the heteropolysaccharide using chemical, enzymatic, and chromatographic procedures showed that it consists of D-mannopyranose and D-galactopyranose residues (molar ratio, 2.54:1). The main chain of this galactomannan consists of 1,4-beta-D-mannopyranose residues, 39.2% of which are substituted at C6 with single residues of alpha-D-galactopyranose. The probability of occurrence of mannobiose units differentially substituted with galactose was determined by 13C-NMR data and equaled, respectively, 0.37, 0.47, and 0.16 for non-substituted Man-Man units, monosubstituted Gal(Man-Man) and (Man-Man)Gal units taken together, and for the disubstituted Gal(Man-Man)Gal units.
Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr. 33, Moscow, 117071 Russia.
A V
AV
Egorov
N M
NM
Mestechkina
V D
VD
Shcherbukhin
D005690:Galactose / Q000737:chemistry / Q000031:analogs & derivatives; D031501:Gleditsia / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008351:Mannans / Q000032:analysis / Q000737:chemistry*; D008358:Mannose / Q000737:chemistry; D008970:Molecular Weight; D012639:Seeds / Q000737:chemistry; D012996:Solutions; D014783:Viscosity; D014867:Water
D008351:Mannans; D012996:Solutions; D014867:Water; C012990:galactomannan; D008358:Mannose; D005690:Galactose