Isolation and Characterization of Alginate from Hizikia fusiformis and Preparation of its Oligosaccharides

Abstract

In this study, alginate was isolated from the residues of Hizikia fusiformis, after extraction of the fucoidan. The yield, total carbohydrate, uronic acid, ash and moisture of alginate was 2.6% (based on wet material), 85.2, 80.5, 12.1 and 2.2%, respectively. The molecular mass of alginate was calculated to be about 7.0×10⁴. The ¹H- and ¹³C-NMR and IR spectra of alginate from H. fusiformis were in agreement with those of standard alginate. From the integral of the anomeric proton signals of D-mannuronic (M) and L-guluronic (G) acid residues in the ¹H-NMR spectrum, the molar ratio of both residues was calculated to be M: G=0.53: 1. Eight alginate oligosaccharides were also isolated by gel permeation chromatography after using commercially available enzymes and were characterized by 2 D NMR techniques and ESI-MS spectrometry as Δ(4-deoxy-L-erythro-hex-4-enopyranosyluronate) GGGG, ΔGGG, ΔGG, ΔG, ΔMMMM, ΔMMM, ΔMM and ΔM.