Key Enzymes in Soybean Isoflavones Biosynthesis and Its Metabolic Engineering

Isoflavones were one class of secondary metabolites with C-6/C-3/C-6 skeleton,which possessed anti-oxidant and anti-tumor activities.Isoflavones and flavonoids had similar phenylpropanoid biosynthetic pathway.The majority of natural isoflavones occurred in leguminous plants.At present,more than 12 isoflavones were identified in soybean.The biosynthesis of soybean isoflvones mainly involved three key enzymes,which are CHS(chalcone synthase),CHI(chalcone isomerase),and IFS(isoflavone synthase).summarized The extraction and isolation methods and biosynthesis pathway of soybean isoflavones were summarized,and emphatically reviewed the biological characteristic and functions of CHI,CHS,and IFS as well as isoflovnes metabolic engineering were emphatically reviewed.