Figure 3
From: Theoretical study on the glycosidic C–C bond cleavage of 3’’-oxo-puerarin
Possible metabolism of puerarin (1) by the mechanism of GH4 and 109 enzymes. The carbanion species, its endiolate tautomer is shown at (C), is the key intermediate in the mechanism. In the case of puerarin (1) metabolism, DgpA produces 3-oxo-puerarin (2) (A,B) and the next reactions (B,D) are catalyzed by DgpBC to produce hexose enediolone (blue in (D)) and aglycone. R in the structures may be O-, C-, or N-glycosides.
