Structural characteristics of oxalate-soluble polysaccharides of Sosnowsky's hogweed (Heracleum sosnowskyi Manden)

• Published in: Carbohydrate polymers Vol. 153; pp. 66 - 77
• Main Authors: Makarova, Elena N., Shakhmatov, Evgeny G., Belyy, Vladimir A.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 20.11.2016
• Subjects: Arabinogalactan II; Arabinogalactan proteins; Galactans - analysis; Heracleum - chemistry; Heracleum sosnowskyi; Magnetic Resonance Spectroscopy; Mucoproteins - analysis; NMR; Oxalates - chemistry; Pectin; Pectins - analysis; Plant Proteins - analysis; Polysaccharides - analysis; Solubility; Structure; Arabinogalactan II; Arabinogalactan proteins; NMR; Pectin; Structure; Heracleum sosnowskyi
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2016.07.089

•The chemical structure of pectin and AGP of H. sosnowskyi has been characterized.•The side chains of the hogweed pectin are composed of AG-I and 1,5-α-L-arabinan.•AGP consists of 1,3-, 1,6-, 1,3,6-β-Galp, 1,5-, 1,3,5-a-Araf, 4-O-Me-, 1,4-β-GlcpA.•A part of pectin is probably covalently linked to AGP.•AGP is directly linked to the RG-I region of the pectin. Arabinogalactan proteins (AGP) and pectic polysaccharides were isolated from above-ground parts of Heracleum sosnowskyi. The structural study has shown that a linear region of the pectic macromolecules consists of 1,4-α-d-galactopyranosyluronan blocks partially methyl esterified and acetylated. The branched region consists of 3-O- and partially 2-O-acetylated rhamnogalacturonan I. Side chains of the RG-I backbone include the regions of arabinogalactan I and branched 1,5-α-l-arabinan. The carbohydrate part of AGP consists of arabinogalactan II with a 1,3-β-d-Galp main chain. The side chains of the branched area of AG-II are composed of 1,6-β-d-Galp, 1,5-, 1,3,5-α-l-Araf, 4-O-Me-β-d-GlcA and 1,4-β-d-GlcpA, and non-reducing ends residues of β-d-Galp, α-l-Araf, α-l-Rhap and α-l-Fucp. The branch points of the main and side chains are formed by 3,6-di-O-substituted β-d-Galp. It was found that at least a portion of pectin is probably covalently linked to AGP, wherein AGP is linked to RG-I, but not with galacturonan.