Spectroscopic study of natural and synthetic polysaccharide sulfate structures

Abstract

Sulfate-containing polysaccharides are a diverse group of natural products and many of them have shown biological activity. Therefore, a growing interest has focused on the chemical preparation of sulfated derivatives from common polysaccharides. The analysis of these complicated, synthetically prepared polysaccharide sulfates typically requires the utilization of several methods. NMR and IR spectroscopy are routinely used to follow the progress of the sulfation reactions and to confirm the presence of covalently bonded sulfate groups in the products.

Synthesis and characterization of starch sulfates obtained by the sulfamic acid-urea complex

“…The presence of absorption bands at 808-817 cm -1 and 859-867 cm -1 , which are absent in the FTIR spectrum of the initial starch, indicates the presence of primary and secondary sulfates of the sodium salt of starch (Fig. 5), which is consistent with the data presented in the works [36][37][38].…”

Applications of infrared spectroscopy in polysaccharide structural analysis: Progress, challenge and perspective

“…IR spectroscopy is a reliable analytical method used to confirm existences of different substitution groups in polysaccharides, due to its sensitivity, quick readout, and minimal sample requirement ( Caputo et al, 2019 ). It can also be applied to follow the progress of substitution reaction of synthetic substituted polysaccharides, as the attachment of substitution groups to polysaccharide backbone results in new absorption bands in the IR spectra ( Korva, Karkkainen, Lappalainen, & Lajunen, 2016 ). Some common substituent groups in polysaccharides including sulfonyl, acetyl, phosphoryl and carboxymethyl groups and their characteristic wavenumbers are summarized in Table S1 .…”

Sulfated Polysaccharide from the Marine Sponge Callyspongia vaginalis

“…Estes polissacarídeos naturais ocorrem com frequência em algas vermelhas, possuem estrutura dimérica, formada por unidades D-galactopiranose com padrões glicosídicos α1→3 e β1→4. Os tipos mais comuns de carrageninas são ι (lota), κ (kappa) e λ (lambda) que se distinguem entre si pelo padrão de substituição do grupo sulfato e teor 3,6 de anidrogalactose, [28][29][30] conforme apresentado na Figura 4.…”