Plant flavonoids are important medicinal ingredients,whose biological function is closely related to chemical structure,and its stability,protein affinity and bioavailability can be improved by O-methylation modification,thereby enhancing its medicinal activity.O-Methyltransferase（OMT）catalyzes the synthesis of O-methylated derivatives of flavonoids,which is a key modifying enzyme in the flavonoid metabolism.This article reviews the chemical structure,medicinal function,and mechanism of medicinal value enhancement of plant O-methylated flavonoids.It is summarized in this article the biological function,expression regulation,and potential of plant flavonoid O-methyltransferases,in order to provide new ideas and ways for the further research of plant methylated flavonoids.

lavonoids, O-methylation, O-methyltransferases