Structural characterization of mesquite (Prosopis velutina) gum and its fractions.
Structural and physicochemical characteristics of mesquite gum (from Prosopis velutina) were investigated using FT-IR spectroscopic, mass spectrometric and chromatographic methods. Four fractions (F-I, F-IIa, F-IIb and F-III) were isolated by hydrophobic interaction chromatography. The samples were characterized and analyzed for their monosaccharide and oligomers composition by high performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). L-Arabinose (L-Ara) and D-galactose (D-Gal) were found as the main carbohydrate constituent residues in the polysaccharides from mesquite gum and their ratio (L-Ara/D-Gal) varied within the range 2.54 to 3.06 among the various fractions. Small amounts of D-glucose (D-Glc), D-mannose (D-Man) and D-xylose (D-Xyl) were also detected, particularly in Fractions IIa, IIb and III. Infrared spectroscopy identified polysaccharides and protein in all the samples. Data from mass spectrometry (MALDI-TOF MS) was consistent with the idea that the structure corresponding to the periphereal chains of Fraction I is predominantly a chain of pentoses attached to uronic acid.
López-Franco
Yolanda L
YL
Laboratory of Biopolymers, Centro de Investigación en Alimentación y Desarrollo, P.O. Box 1735, Hermosillo, Sonora 83000, Mexico.
de la Barca
Ana M Calderón
AM
Valdez
Miguel A
MA
Peter
Martin G
MG
Rinaudo
Marguerite
M
Chambat
Gérard
G
Goycoolea
Francisco M
FM
D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006601:Hexoses / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods; D053149:Plant Gums / Q000032:analysis*; D029862:Prosopis / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods
D006601:Hexoses; D053149:Plant Gums; C416517:prosopis gum