Supporting information for "2D NMR spectroscopy allows structure verification of full-sized natrium alginate: case study of Cystoseira barbata"

Abstract Industrial sample of full-sized natrium alginate from Cystoseira barbata was studied by 1D 1H and for the first time by 2D (1H-13C HMQC) NMR spectroscopy. The monomeric composition of alginate was established by means of 1H NMR technique: it contains 43% of D-mannuronic acid (M) and 57% of L-guluronic acid (G). Dimeric blocks content was FMM = 25%, FGG = 39% and FMG = FGM = 18%, hence homopolymeric blocks prevail heteropolymeric once (η = 0,73). The monomeric composition of natrium alginate from Cystoseira barbata is similar to previously reported composition of alginates from Ascophyllum nodosum, Sargassum asperifolium and Sargassum filipendula. The novel data from 2D NMR spectroscopy of full-sized alginate coincides with 2D NMR data obtained earlier for short (≤6) blocks prepared by enzymatic hydrolysis. All twenty H/C correlations of both M and G homopolymers and heteropolymers are clearly distinguishable on the 2D HMQC NMR spectrum at both 45°C and 90°C Data content This archive contains raw NMR data fids, obtained in the publication above