Résumé
Rhamnogalacturonan II (RG-II), a small complex pectic polysaccharide is released from Agave pulquero stems (Agave mapisaga), after the production period of aguamiel. RG-II was obtained by treatment with two commercial liquefying enzyme preparations, it was isolated by size-exclusion chromatography and characterized. RG-IIs contains diagnostic sugars such as apiose, 2-O-methyl-L-fucose, 2-O-methyl-D-xylose, aceric acid, Kdo and Dha. Glycosyl-linkage compositions of the Agave pulquero RG-II like structures are similar to the theoretical model described through sycamore RG-II structure. The presence of T-linked apiose indicates that the obtained juice from Agave pulquero plant contains the free RG-II dimer. Thus, when pectinolytic enzyme preparations are used to process Agave pulquero (A. mapisaga), RG-II is released as one of the main soluble polysaccharide fraction.