Rhamnetin production based on the rational design of the poplar O-methyltransferase enzyme and its biological activities.

To produce rhamnetin using enzymatic engineering, poplar O-methyltransferase-7 and its mutants were prepared based on the rational enzyme design, and the production of rhamnetin was compared with the results obtained using the wild type enzyme. In addition, the potential of using rhamnetin as a cancer chemopreventive agent was compared with that of quercetin in MDA-MB-231 human breast cancer cells, and their bioavailabilities were tested in Dulbecco's modified Eagle's medium.