Structural characterization and rheological behavior of a heteroxylan extracted from Plantago notata Lagasca (Plantaginaceae) seeds

Plantago notata (Plantaginaceae) is a spontaneous plant from Septentrional Algerian Sahara currently used by traditional healers to treat stomach disorders, inflammations or wound healing. A water-soluble polysaccharide, called PSPN (PolySaccharide fraction from Plantago Notata), was extracted and purified from the seeds of this semi-arid plant. The structural features of this mucilage were evaluated by colorimetric assays, Fourier transformed infrared spectroscopy (FT-IR), gas chromatography coupled to mass spectrometry (GC/MS) and H-1/C-13 Nuclear Magnetic Resonance (NMR) spectroscopy. PSPN is a heteroxylan with a backbone composed of beta-(1,3)-D-Xylp and beta-(1,4)-D-Xylp highly branched, through (0)-2 and (0)-3 positions of beta-(1,4)-D-Xylp by various side chains and terminal monosaccharides such as alpha-L-Araf-(1,3)-beta-d-Xylp, beta-D-Xylp (1,2)-beta-D-Xylp, terminal Xylp or terminal Araf. The physico-chemical and rheological analysis of this polysaccharide in dilute and semi diluted regimes showed that PSPN exhibites a molecular weight of 2.3 x 10(6) g/mol and a pseudoplastic behavior. (C) 2017 Elsevier Ltd. All rights reserved.