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Novel arabinan and galactan oligosaccharides from dicotyledonous plants.

Wefers D, Tyl CE, Bunzel M - Front Chem (2014)

Bottom Line: To get a detailed insight into their fine structure, various oligosaccharides were isolated from quinoa, potato galactan, and sugar beet pulp after enzymatic treatment.Additionally, an oligosaccharide with two adjacent arabinofuranose units O2-substituted with two ferulic acid monomers was characterized.The isolated oligosaccharides gave further insight into the structures of pectic side chains and may have an impact on plant physiology and dietary fiber fermentation.

View Article: PubMed Central - PubMed

Affiliation: Department of Food Chemistry and Phytochemistry, Institute of Applied Biosciences, Karlsruhe Institute of Technology Karlsruhe, Germany.

ABSTRACT
Arabinans and galactans are neutral pectic side chains and an important part of the cell walls of dicotyledonous plants. To get a detailed insight into their fine structure, various oligosaccharides were isolated from quinoa, potato galactan, and sugar beet pulp after enzymatic treatment. LC-MS(2) and one- and two-dimensional NMR spectroscopy were used for unambiguous structural characterization. It was demonstrated that arabinans contain β-(1→3)-linked arabinobiose as a side chain in quinoa seeds, while potato galactan was comprised of β-(1→4)-linked galactopyranoses which are interspersed with α-(1→4)-linked arabinopyranoses. Additionally, an oligosaccharide with two adjacent arabinofuranose units O2-substituted with two ferulic acid monomers was characterized. The isolated oligosaccharides gave further insight into the structures of pectic side chains and may have an impact on plant physiology and dietary fiber fermentation.

No MeSH data available.


CID MS2 mass spectrum of compound 3 in negative mode (m/z 765).
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Figure 5: CID MS2 mass spectrum of compound 3 in negative mode (m/z 765).

Mentions: A Viscozyme L hydrolyzate of sugar beet pulp was fractionated by using Sephadex LH-20 chromatography, and compound 3 was obtained from the methanol/water 70/30 eluate. After semipreparative HPLC purification, monosaccharide analysis of the purified compound showed l-arabinose as the only monosaccharide present. ESI-MS showed a quasimolecular ion [M-1]− at m/z 765, corresponding to three arabinose units, esterified with two ferulic acids. The MS2 spectrum yielded mass losses of 60 and 90 Da (m/z 705 and m/z 675), typical for cross ring cleavages through a 5-substituted, reducing arabinose (Figure 5). A weak interglycosidic cleavage fragment (m/z 633) is also present, suggesting that ferulic acid is not attached to the reducing arabinose. The remaining fragments (m/z 499 and m/z 529) may result from a mass loss of 176 Da of the fragments at m/z 705 and m/z 675, corresponding to a loss of an anhydro-ferulic acid. Levigne et al. (2004) isolated a diferuloylated oligosaccharide showing the same quasimolecular ion from sugar beet. The MS2 spectrum of that compound showed different intensities of the fragment ions than the compound analyzed here. It also contained only minor amounts of the fragments at m/z 499 and m/z 529. These fragments were assigned to impurities by the authors. They proposed a structure where an (1→5)-linked arabinotriose is esterified by two ferulic acids at O2 of the (1→5)-linked arabinose and at O5 of the terminal arabinose. The differences in the MS2 spectrum suggest that the positions of esterification could be different in the compound analyzed here.


Novel arabinan and galactan oligosaccharides from dicotyledonous plants.

Wefers D, Tyl CE, Bunzel M - Front Chem (2014)

CID MS2 mass spectrum of compound 3 in negative mode (m/z 765).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4226231&req=5

Figure 5: CID MS2 mass spectrum of compound 3 in negative mode (m/z 765).
Mentions: A Viscozyme L hydrolyzate of sugar beet pulp was fractionated by using Sephadex LH-20 chromatography, and compound 3 was obtained from the methanol/water 70/30 eluate. After semipreparative HPLC purification, monosaccharide analysis of the purified compound showed l-arabinose as the only monosaccharide present. ESI-MS showed a quasimolecular ion [M-1]− at m/z 765, corresponding to three arabinose units, esterified with two ferulic acids. The MS2 spectrum yielded mass losses of 60 and 90 Da (m/z 705 and m/z 675), typical for cross ring cleavages through a 5-substituted, reducing arabinose (Figure 5). A weak interglycosidic cleavage fragment (m/z 633) is also present, suggesting that ferulic acid is not attached to the reducing arabinose. The remaining fragments (m/z 499 and m/z 529) may result from a mass loss of 176 Da of the fragments at m/z 705 and m/z 675, corresponding to a loss of an anhydro-ferulic acid. Levigne et al. (2004) isolated a diferuloylated oligosaccharide showing the same quasimolecular ion from sugar beet. The MS2 spectrum of that compound showed different intensities of the fragment ions than the compound analyzed here. It also contained only minor amounts of the fragments at m/z 499 and m/z 529. These fragments were assigned to impurities by the authors. They proposed a structure where an (1→5)-linked arabinotriose is esterified by two ferulic acids at O2 of the (1→5)-linked arabinose and at O5 of the terminal arabinose. The differences in the MS2 spectrum suggest that the positions of esterification could be different in the compound analyzed here.

Bottom Line: To get a detailed insight into their fine structure, various oligosaccharides were isolated from quinoa, potato galactan, and sugar beet pulp after enzymatic treatment.Additionally, an oligosaccharide with two adjacent arabinofuranose units O2-substituted with two ferulic acid monomers was characterized.The isolated oligosaccharides gave further insight into the structures of pectic side chains and may have an impact on plant physiology and dietary fiber fermentation.

View Article: PubMed Central - PubMed

Affiliation: Department of Food Chemistry and Phytochemistry, Institute of Applied Biosciences, Karlsruhe Institute of Technology Karlsruhe, Germany.

ABSTRACT
Arabinans and galactans are neutral pectic side chains and an important part of the cell walls of dicotyledonous plants. To get a detailed insight into their fine structure, various oligosaccharides were isolated from quinoa, potato galactan, and sugar beet pulp after enzymatic treatment. LC-MS(2) and one- and two-dimensional NMR spectroscopy were used for unambiguous structural characterization. It was demonstrated that arabinans contain β-(1→3)-linked arabinobiose as a side chain in quinoa seeds, while potato galactan was comprised of β-(1→4)-linked galactopyranoses which are interspersed with α-(1→4)-linked arabinopyranoses. Additionally, an oligosaccharide with two adjacent arabinofuranose units O2-substituted with two ferulic acid monomers was characterized. The isolated oligosaccharides gave further insight into the structures of pectic side chains and may have an impact on plant physiology and dietary fiber fermentation.

No MeSH data available.