Synthesis of S-nitrosoglutathione-alginate for prolonged delivery of nitric oxide in intestines

Figures & data

Figure 1. Reaction scheme for the synthesis of SNA. 1st step: synthesis of an alginate-glutathione conjugate. 2nd step: nitrosation of alginate-glutathione conjugate.

Table 1. Amount of glutathione (SH groups) determined by Ellman’s test (precursor of SNA F1).

Glutathione fraction	Ellman’s method (μmol/g)
Reduced thiols	214 ± 10
Total thiols	711 ± 24
Directly linked thiols	481 ± 22

Table 2. Amount of glutathione (SH groups) determined by Ellman’s test (precursor of SNA F2).

Glutathione fraction	Ellman’s method (μmol/g)
Reduced thiols	711 ± 24
Total thiols	711 ± 24
Directly linked thiols	481 ± 22

Table 3. Amount of nitrites determined by the Griess and Saville tests.

	SNA F1	SNA F2
Nitrites (μmol/g)	174 ± 21	468 ± 23

Figure 2. Stability of SNA F1

SNA F2

in the Ussing chamber without rat intestine at 37 °C (n = 3, mean ± SD).

Figure 3. Stability of SNA F2 at different pH conditions at 4 °C in dark pH 1.2

pH 7.0

and pH 8.4

(n = 3, mean ± SD).

Figure 4. Concentrations of GSNO

NO₂/NO

and NO₃ (

) as the percentage of the initial concentration of the donor chamber (100 μM). Donor chamber; (n = 3, mean value ± SD).

Figure 5. Concentrations of GSNO

NO₂/NO

and NO₃

as the percentage of the initial concentration of the donor chamber (100 μM). Acceptor chamber; (n = 3, mean value ± SD).

Figure 6. Concentrations of SNA F2

NO₂/NO

and NO₃

as the percentage of the initial concentration of the donor chamber (100 μM). Donor chamber; (n = 3, mean value ± SD).

Figure 7. Concentrations of SNA F2

NO₂/NO

and NO₃

as the percentage of the initial concentration of the donor chamber (100 μM). Acceptor chamber; (n = 3, mean value ± SD).

Figure 8. Cell viability of Caco2 cell line after exposure to different concentrations of alginate, alginate-GSH conjugate and SNA F2 (n = 3, mean ± SD). For SNA F2, the concentrations are expressed in μM of NO; for the other polymers, corresponding concentration are used. *Kruskal–Wallis test (comparison with alginate): p < 0.05.