- a Institute of Chemistry, Komi Science Centre, Urals Branch of the Russian Academy of Sciences, Pervomaiskaya St. 48, Syktyvkar 167982, Russia
- b Institute for Problems of Chemical and Energetic Technologies, Siberian Branch of the Russian Academy of Sciences (IPCET SB RAS), Biysk 659322, Russia
- Received 7 April 2015, Revised 9 October 2015, Accepted 12 October 2015, Available online 22 October 2015
Highlights
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- Heracleum sosnowskyi pectic polysaccharide structures were characterized for the first time.
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- RG-I side chains are formed out of T-β-d-Galp, 1,4-β-d-Galp, 1,6-β-d-Galp.
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- AGP carbohydrate backbone consists of 1,3- and 1,3,6-β-d-Galp residues.
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- AGP side chains consist of 1,6-β-d-Galp, 1,5-α-l-Araf, 4-OMe-β-d-GlcpA.
Abstract
Polymers with different structures were isolated from the aboveground part of Heracleum sosnowskyi Manden. The sequential treatment of Heracleum with water, HCl solution, and (NH4)2C2O4
solution was observed to decrease the arabinogalactan proteins (AGP)
content and increase the pectins content in the extracted
polysaccharides. The linear region of the HSO-I
polysaccharide having the highest yield was found to be composed mainly
of partially methylesterified homogalacturonan fragments, whereas the
branched region was made up of fragments of rhamnogalacturonan I whose
core represents 1,2-α-l-rhamno-1,4-α-d-galacturonan. The carbohydrate side chains of the branched region are linked to the α-l-Rhap core residues via the 1,4-glycosidic bond and consist chiefly of T-β-d-Galp, 1,4-β-d-Galp and 1,6-β-d-Galp residues indicating the presence of the 1,4-β-d-galactan. NMR spectroscopy revealed the carbohydrate moiety of the AGP molecule to consist mainly of 1,3- and 1,3,6-β-d-Galp residues. The side chains comprised 1,6-β-d-Galp, terminal 4-O-Me-β-d-GlcpA, and β-d-Galp.
Keywords
- Heracleum sosnowskyi;
- Pectin;
- Arabinogalactan protein;
- Structure;
- NMR
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