원문정보
초록
영어
Silk fibroin (Bombyx mori ) is a structure protein with low solubility limiting its applications in aqueous environments. In order to improve its solubility, in this report, regenerated fibroin was sulfated using aqueous sulfuric acid. The reaction temperature and sulfuric acid concentration were varied for the investigation of optimum sulfation condition.
The sulfated fibroin samples were neutralized by alkali, followed by dialysis and freeze drying. Their FT-IR spectra proved varying degree of introduction of sulfate group during the sulfation reaction, showing a strong absorption at 1145 cm-1 corresponding to the stretching vibration of S=O bond. NMR spectra indicated that sulfation occurred mainly at serine residues. This result agreed well with the previous reports1)2).
The maximum yield was obtained at 70℃ and the degree of sulfation increased with sulfuric acid concentration. A sharp absorption peak at 997 cm-1 was appeared above 15% of sulfuric acid, suggesting an unidentified sulfation reaction occurs at high sulfate concentration. The ratio of sulfated groups also increased with the reaction time. The recovery yield of sulfated fibroin was around 50% in a small scale experiment in alaboratory. A successive large scale experiment produced 36.97g of sulfated fibroin with 72.5% weight yield.