Approach for oilgochitosan via chitinase system and the chemical modification

Abstract

Chitinase was prepared from bacteria, Staphylococcus species strain TU005 (E), found in Thailand soil. The activity was 18 mU/mg as determined by colorimetric assay at 37℃. Oligochitosan obtained from enzymatic degradation was found to be one-third of the starting chitosan as clarified by intrinsic viscosity. N-Phthaloylation at C-2 position was conducted to protect amino group. The compound showed the characteristic peaks of phthalimido group at 1714 and 1775 cm-1 by FT-IR. The product became well dissolved in DMF, DMSO, and pyridine. The precursor, O-tosylation of oligochitosan, was successfully prepared at room temperature under homogeneous system as confirmed from the tosyl peak at 817, 1599, and 1173 cm-1. The conjugation of long chain alkyl onto the precursors was prepared to obtain O-Lauryl-N-Phthaloyloligochitosan as evidenced from the significant peak at 2926 cm-1. The XRD patterns of these oligochitosan derivatives implied that the reaction decreased the crystallinity of the starting oligochitosan.