Structural Characterization and Cytotoxic Properties of a 4-O-Methylglucuronoxylan from Castanea sativa

Abstract

A glucuronoxylan was purified from a delignified holocellulose alkaline extract of Castanea sativa (Spanish chestnut) and its structure analyzed by means of FT-IR, GC of the per-trimethylsilylated methylglycoside derivatives, and 1H and 13C NMR spectroscopy. The results supported a structure based on a linear polymer of xylopyranose units linked with beta(1-->4) bonds in which, on average, one out of every six units is substituted at C-2 by a 4-O-methylglucuronic acid unit; this structure is typical of a hardwood acidic 4-O-methylglucuronoxylan (MGX) with an estimated degree of polymerization of 200. The MGX from C. sativa inhibited the proliferation of A431 human epidermoid carcinoma cells with an IC50 value of 50 microM. In addition, this xylan inhibited A431 cell migration and invasion. Preliminary experiments showing that secretion of metalloproteinases MMP2 and MMP9 by A431 tumor cells was inhibited by the purified C. sativa MGX strongly suggest that this mechanism of action may play a role in its antimigration and anti-invasive properties.

Simultaneous production of endo-β-1,4-xylanase and branched xylooligosaccharides by Thermomyces lanuginosus

“…In contrast to earlier papers Nacos et al, 2006), our signal assignment is complete (Table 1) and corresponds to the structure MeGlcA 3 Xyl 4 . The assignment is in full agreement with the signal assignment of glucuronoxylans (Kardošová et al, 1998;Moine et al, 2007) and of shorter aldouronic acids synthesized chemically (Kováč et al, 1980;Hirsch et al, 1981;Cavagna et al, 1984;Excoffier et al, 1986).…”

Structural Patterns of Rhamnogalacturonans Modulating Hsp-27 Expression in Cultured Human Keratinocytes

“…Thus, the size of these polysaccharides, as well as their characteristic monosaccharidic composition, seems to modulate their biological activity. These conclusions are supported by several reports [6,18,19,20] in which similar structure/function relationships have been observed. In their review dedicated to bioactive polysaccharides [7], Paulsen and Barsett pointed out that most of these molecules presented a typical rhamnogalacturonan I backbone.…”

Chemical Characterization of Non-Saccharidic and Saccharidic Components of Rapeseed Hulls and Sunflower Shells

“…The detection of signals assigned to 4-O-methylglucuronic acid residues not detected by ionic chromatography, in addition to xylan signals, reveals that glucuronoxylan was the principal hemicellulose of SS. The chemical shifts of both residues were in accordance with those described for glucuronoxylans from other materials (Moine 2007). The presence of a small amount of pectic galacturonans was also detected.…”

“…Pectin can also be used in polymeric/oligomeric/monomeric forms in the food industry (Ciriminna et al 2015). Pectins and hemicelluloses can be extracted from biomass using traditional solidliquid extraction in aqueous acid or basic media, respectively (May 1990;Moine 2007).…”