Mechanism of sulfonation-induced chain scission of selectively oxidized polysaccharides

One-step synthesis of gold nanoparticles for catalysis and SERS applications using selectively dicarboxylated cellulose and hyaluronate

“…For 13 C and 1 H- 13 C NMR spectra of DCC and DCH, as well as full signal assignment, see our previous works. [24,29,31] Obtained 1 H NMR spectra well illustrate the different nature of each DCP. The presence of four distinct signals of H1, H4, H5, and H6 (there are no protons on C2 and C3) in the spectra of DCC indicates a well-defined structure composed of 2,3-oxidized AGU units connected by β-(1→4) glycosidic linkages.…”

“…DO of oxidized cellulose, i.e. the percentage of AGU converted to 2,3-dicarboxylated cellulose units, was determined from 1 H NMR spectra by comparing the average of H4 and H5 signal intensities (3.98-4.03 ppm, signals of oxidized units) with the sum of the signals at 4.43 ppm and 4.95 ppm, which were identified as H1' of non-oxidized cellulose units neighboring charged oxidized moieties (4.95 ppm) [29,31] and as H1' of non-oxidized cellulose units with non-oxidized neighbors [32]. The DO of prepared DCH samples was determined by the comparison of signal intensities of H4 and H5 from oxidized glucuronic acid units (4.07 and 4.19 ppm) and well-separated signal H5' (3.48 ppm) of intact N-acetyl-D-glucosamine unit, which is resistant to periodate oxidation.…”

“…The use of DCPs has several key advantages over the current methods employing only the periodate-oxidized dialdehyde polysaccharides (DAPs), such as dialdehyde nanocelluloses [25][26][27], which feature a highly complex composition composed of a mixture of various intra-and intermolecular hemiacetals [28]. Further oxidation used in DCP preparation i) improves the material composition by disrupting the hemiacetals in DAPs [29], ii) introduces a pair of -COOH groups in each oxidized unit capable of efficient stabilization of Au clusters and nanoparticles [30], iii) allows for easy control over the molecular weight of DCPs. The last is achieved by the recently developed sulfonation-induced chain scission method based on the addition of sulfamic acid into the reaction mixture, which leads to controlled hydrolysis of DCP chains [24,29].…”

“…Further oxidation used in DCP preparation i) improves the material composition by disrupting the hemiacetals in DAPs [29], ii) introduces a pair of -COOH groups in each oxidized unit capable of efficient stabilization of Au clusters and nanoparticles [30], iii) allows for easy control over the molecular weight of DCPs. The last is achieved by the recently developed sulfonation-induced chain scission method based on the addition of sulfamic acid into the reaction mixture, which leads to controlled hydrolysis of DCP chains [24,29]. Hence, by the careful selection of source materials, modification of primary (periodate) oxidation, which dictates the degree of oxidation (DO), and by the adjustment of molecular weight during secondary oxidation, one could obtain DCPs featuring the well-defined structure of oxidized units, distinctly different architecture of macromolecular chains, variable DO and adjustable molecular weight, all of which can influence the growth of AuNPs.…”

Polysaccharides from Russula: a review on extraction, purification, and bioactivities

“…Moreover, the sulfated polysaccharides derived from R. virescens have been found to effectively combat the growth of Escherichia coli , primarily due to a magnification of the intrinsic anti-bacterial potency of the unmodified polysaccharides ( 14 ). Specifically, sulfonic acid groups (–SO 3 H) can be incorporated into polysaccharide molecules to replace the hydroxyl group (–OH) after sulfonation ( 97 ). This modification enhances the affinity between the sulfated polysaccharide from Russula virescens and bacterial receptors, improving its recognition and binding ability by altering the spatial structure and conformation of the polysaccharide ( 98 ).…”