Abstract

• The main aim of the research is to study the deacetylation of chitin extracted from prawn shell by enzymatic method and to evaluate scientifically on some biological activities. The isolation of chitin deacetylase producing Bacillus thermoleovorans from soil and bioconversion of chitin to chitosan and water soluble chitosan (WS-chitosan) was converted from the prepared E-chitosan by oxidative depolymerization method. Some pharmacological activities such as antimicrobial activity, antitumor activity, antioxidant activity, acute toxicity, weight loss activity and antilipidemic activity of water soluble chitosan (WS-chitosan) were currently assayed. The antimicrobial activity of WS-chitosan was more effective on gram positive bacteria than gram negative bacteria. The antitumor activity of WS-chitosan was assayed by potato crown gall (PCG) method. It was found that, the different concentration ranges of chitosan have different inhibited tumor growth manner. In the determination of antioxidant activity of WS-chitosan, the IC50 was found to be 4.20 g/mL. The acute toxicity test of WS-chitosan on albino mice done by the method of the Litchfield and Wilcoxon indicated no toxic effect. According to the study on the weight loss activity of WSchitosan on albino mice carried out by the method of Han et al., 1999, the 600 mg/kg b. wt dose of WS-chitosan is the most eligible dose to reduce the body weight of male and female albino mice. In the investigation of antilipidemic activity of WS-chitosan on albino rats, it was observed the significantly decrease in the “bad” cholesterol: LDL cholesterol and increase in “good”cholesterol : HDL cholesterol. Treatment with WS-chitosan (600mg/kg b.wt) significantly decreased in levels at TC by 59 % , TG by 62 % and LDL by 40 % and 26 % increased in HDL levels at 21 days.