生物氧化还原.PPT

Study on hydroxylation of oleanolic acid by microbes Introduction Approaches to improve its bioavailability Make its salts to improve its water-solubility. Reform its molecule with active group (OH, NH2, NO2, glucoside, etc) by chemical synthesis. Preparation of 11-oxooleanolic acid and its derivatives Aim of the present project Main contents of the research project 1.Selection of the desired strain with high activity of hydroxylase. Selection of the desired strain The strain candidates: Several fungi strains possessing the hydroxylation capacity preserved in our lab Methods: Initial selection and mutation Initial selection Selection of cosolvents for hydroxylation Effect of ethanol on microbial growth Effect of ethanol on hydroxylation Effect of quantity and addition time of the inducer Effect of quantity and addition time of the inducer Effect of substrate feeding mode on hydroxylation of OA Discussion on the fed batch mode The inhibition of OA on P450. OA is almost insoluble in water. Therefore, the substrate was fed in batch mode with a small dosage to keep the appropriate low content of OA in the medium. Characterization of the productby MS Characterization of the productby MS Conclusion Aspergillus ochraceus NG1203 was selected as the desired strain Optimal conditions: (1) 2mg/L OA as inducer was added after incubation 20h. (2) The content of ethanol as the cosolvent in the medium was 3% (V/V). (3) The substrate was added sequentially with a small dosage, and the content of OA was finally 200mg/L. Prospect The characterization of the product is still at work; The further optimization of hydroxylation is studied to enhance the yield of hydroxylation; The further derivative reaction is in the preparation; Prospect The problem how to release the inhibition of OA on P450 is still at work. The regeneration of coenzyme NADPH is the key problem to continue hydroxylation. Oleanolic Acid (OA) Pharmacological activities Antiinflammation Anti