Preparation and properties of reduced chitooligomers

In order to prevent the browning of the chitooligomer product prepared from enzymatic hydrolysis, the chitooligomers were reduced by potassium borohydride. The chemical structures and physical properties of the reduced chitooligomers were characterized by magnetic resonance spectra, X-ray diffraction, UV-spectrophotometry, thermogravimetric analysis, differential thermal analysis. The chemical stability of the chitooligomers increased after reduction. The reduced chitooligomers had no oral acute toxicity, and they had almost the same inhibition effect against the sarcoma 180 tumor cells in mice by intraperitoneal injection as the fresh chitooligomers.