Beta-chitosan extracted from Loligo Japonica for a potential use to inhibit Newcastle disease

Abstract

Beta-chitosan has a parallel structure, which differs from alpha-chitosan's antiparallel structure while producing different properties and difficulties. In this paper, we prepared the beta-chitosan through acid and alkali methods and the resultant material was characterized by elemental analysis, FT-IR, HPLC, XRD, NMR and AFS. To increase the solubility and biological activity of the beta-chitosan, we degraded it through microwave-assisted process. After characterization, we determined that the chitosan had not changed its configuration during the reaction with H2O2 under microwave irradiation. The inhibitory activity of the degraded chitosan for Newcastle disease was revealed by a hemagglutination test and RT-PCR. The yield of the beta-chitosan was approximately 30%, and its molecular weight can be degraded to 1000 to 10,000g/mol. Moreover, the degraded β-chitosan has higher antiviral activity, reducing the hemagglutination titre to zero, compared with alpha-chitosan. Therefore, beta-chitosan has good development prospects during the development of veterinary drugs for Newcastle disease.