Microbial Transformation Of Glycyrrhetinic Acid And Other Bioactive Components From Traditonal Chinese Medicine

Biotransformation is a kind of chemical reaction of structure modification by enzymes from plant cell suspension cultures and microor -ganisms,which modifies the structures of specific substrates.It has such advantages over chemical synthesis as high stereo- and regionselectivity mild reaction conditions,lower cost,as well as less byproducts and pollution.Some reactions which can not be fulfilled by chemical approach are facile process by biotransformation.In this thesis,different microorganisms were selected to biotransf -orm glycyrrhetinic acid,andrographolide,neoandrographolide,deoxyandrographolide and dehydroandrographolide.Mucor Spinosus(AS 3.3450)was chosen to transform Glycyrrhet -inic acid(GA).Four products were isolated and purified.These produ -cts were respectively identified as 24-hydroxyglycyrrhetinic acid,7αhydroxyglycyrrhetinic acid,7β-hydroxyglycyrrhetinic acid,15α-hydroxy -glycyrrhetinic acid.The yield of 7β-hydroxyglycyrrhetinic acid was determined by HPLC and the fermentation conditions were optimized.Microtransformation of andrographolide,neoandrographolide,deoxyandrographolide and dehydroandrographolide was also also inves -tigated in this thesis.Syncephalastrum racemosum(AS3.264)and Mucor polymorphosporus(AS3.3443)were selected from 7 strains of microorganisms to transform andrographolide.Syncephalastrum racemo -sum(AS3.264),Mucor polymorphosporus(AS3.3443),Mucor rouxianus(AS3.3447),Rhizopus stolonifer(AS3.3463)and Absidia coerulea(AS3. 3389)were selected from 7 strains of microorganisms to transform neoandrographolide.Syncephalastrum racemosum(AS3.264),Mucor polymorphosporus(AS3.3443),Mucor rouxianus(AS3.3447),Rhizopus stolonifer(AS3.3463)and Absidia coerulea(AS3.3389)were selected from 7 strains of microorganisms to transform deoxyandrographolide. Syncephalastrum racemosum(AS3.264),Mucor rouxianus(AS3.3447),Rhizopus stolon-ifer(AS3.3463),Cunninghamella elegans(AS3.2028) and Cunninghame-lla elegans(AS3.1207)were selected from 16 strains of microorganisms to transform dehydroandrographolide.