Abstract: Flavonoids are naturally occurring organic compounds that have a variety of biological activities such as antioxidant and anticancer function, preventing osteoporosis and modulating immunity. Structural modification of flavonoids by microbial fermentation produces more structurally novel derivatives, improving the bioavailability. Intestinal flora, endogenous microorganisms and strains with good transformation efficiency are commonly used for structural modification of flavonoids, and the types of transformation reactions include glycosylation, methylation, hydroxylation, hydrogenation and hydrolysis reactions. The microbial transformation of flavonoids is dominated by the interconversion of flavonoid glycosides and glycosides, allowing enrichment of glycoside-like components in large quantities. This article summarizes the current status of research on microbial transformation of flavonoids such as those in soybeans, Citri Reticulatae Pericarpium, Scutellaria baicalensis, and Epimedium brevicornum, which may provide some references for research on the transformation of flavonoids and the development of new drugs.

Key words: microbial transformation; soybean isoflavones; Citri Reticulatae Pericarpium flavonoids; Scutellaria baicalensis flavonoids; Epimedium brevicornum flavonoids