Physicochemical properties and antioxidant activity of chitosan from the blowfly Chrysomya megacephala larvae

In the present study, we extracted the chitosan from the larvae of blowfly Chrysomya megacephala, a new source of insect chitosan, using chemical methods. We evaluated the physical properties of the blowfly chitosan using a variety of approaches, including preliminary color-change identification, molecular weight determination, elemental analysis (EA), Fourier transform infrared spectroscopy (FTIR), solid-state (13)C cross-polarization and magic-angle-spinning nuclear magnetic resonance spectroscopy ((13)C CP/MAS NMR) and scanning electron microscopy (SEM). Its antioxidant property was examined through 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assays. The results showed that the molecular weight of the blowfly chitosan (501 kDa) was lower than that of the commercial chitosan (989 kDa), and its degree of deacetylation (DDA) (87.9-89.6%) was also higher than that of the commercial chitosan (83.8-85.8%). Furthermore, the blowfly chitosan exhibited excellent antioxidant activity and its IC50 value was 1.2 mg/ml. Therefore, the blowfly larvae could be a novel alternative source of chitosan and might be used as a natural antioxidant.