Preparation and characterization of a chemically sulfated cashew gum polysaccharide

Abstract

A goma do cajueiro (GC) foi sulfatada em piridina:formamida usando ácido clorossulfônico como reagente. A confirmação da sulfatação foi obtida por espectroscopia no infravermelho com transformada de Fourier (FTIR) pelo aparecimento da frequência de vibração em 1259 cm -1 devido ao estiramento assimétrico S=O. Os graus de sulfatação foram de 0,02, 0,24 e 0,88, determinados pela percentagem de enxofre. Os dados de ressonância magnética nuclear (RMN) 1D e 2D mostram que a sulfatação ocorreu nos carbonos primários do polissacarídeo. Um aumento de no mínimo 4% na viscosidade da solução foi observado após a sulfatação. Análise termogravimétrica (TGA) indica que o derivado é estável até cerca de 200 ºC. A comparação entre os derivados sulfatados e carboximetilados foi feita no intuito de verificar a possibilidade de formação de complexos polieletrolíticos, já realizada com os carboximetilados.Cashew gum (CG) was sulfated in pyridine:formamide using chlorosulfonic acid as the reagent. Confirmation of sulfation was obtained by Fourier transform infrared (FTIR) spectroscopy through the presence of an asymmetrical S=O stretching vibration at 1259 cm -1 . The degrees of substitution were 0.02, 0.24 and 0.88 determined from the sulfur percentage. 1D and 2D nuclear magnetic resonance (NMR) data showed that the sulfation occurred at primary carbons. An increase of at least 4% of the solution viscosity was observed due to sulfation. The thermal gravimetric curves (TGA) indicate that the derivatives are stable up to ca. 200 °C. The sulfated CG is compared to carboxymethylated CG in order to verify the possibility of the use of the former in the preparation of polyelectrolyte complexes; the latter is already being used for this application.

Oxidized Cashew Gum Scaffolds for Tissue Engineering

“…The spectra of 1 H‐NMR and 2D 1 H‐ 13 C HSQC of CG ( Figure ) were also collected to confirm the successful production of the oxidized derivatives and the maintenance of the integrity of the polymer backbone. Both uni‐ and bidimensional NMR spectra of CG are in accordance with those previously described in the literature . The HSQC spectrum (Figure b) presents the characteristic protons of CG: α‐ d ‐glucose (δ H /δ C 4.95/100.64), α‐ l ‐rhamnose (δ H /δ C 4.81/101.26), β‐ d ‐galactose (1→3) (δ H /δ C 4.69/104.25 and δ H /δ C 4.44/103.9), β‐ d ‐glucuronic acid (δ H /δ C 4.50/103.77), and β‐ d ‐galactose (1→6) (δ H /δ C 4.39/105.0).…”

“…Both uni‐ and bidimensional NMR spectra of CG are in accordance with those previously described in the literature . The HSQC spectrum (Figure b) presents the characteristic protons of CG: α‐ d ‐glucose (δ H /δ C 4.95/100.64), α‐ l ‐rhamnose (δ H /δ C 4.81/101.26), β‐ d ‐galactose (1→3) (δ H /δ C 4.69/104.25 and δ H /δ C 4.44/103.9), β‐ d ‐glucuronic acid (δ H /δ C 4.50/103.77), and β‐ d ‐galactose (1→6) (δ H /δ C 4.39/105.0). Moreover, the last correlation for β‐ d ‐galactose (1→3) (δ H /δ C 4.69/104.25) on the oxidized derivatives constitutes an evidence that the main chain did not undergo degradation by oxidation.…”

Biopolymer Extracted from Anadenanthera colubrina (Red Angico Gum) Exerts Therapeutic Potential in Mice: Antidiarrheal Activity and Safety Assessment

“…A similar molar mass value was also recorded by De Paula et al [42]. These results show that RAG is dimensionally larger than polysaccharides extracted from the trunk exudates of other species, such as cashew gum (molar mass of 2.35 × 10 4 g/mol), obtained from Anacardium occidentale L., which is chemically and structurally similar to RAG [41,43]. The results of elemental analysis for RAG are presented in Table 1 as well.…”

Characterization and cytotoxic activity of sulfated derivatives of polysaccharides from Agaricus brasiliensis

“…The percentage of sulfur (% S) and carbon (% C) were used to calculate the degree of substitution (DS) according to the formula: $$\text{DS}=2.25\times \%\mathrm{normalS}/\%\mathrm{normalC}.$$[22]…”