Biotransformation of puerarin into puerarin-6″-O-phosphate by Bacillus cereus.

The biotransformation of puerarin catalyzed by Bacillus cereus NT02 was studied. A primary screening was carried out using 307 strains of bacteria isolated from soil which were able to grow in the presence of puerarin. Strain NT02, identified as B. cereus, was able to convert puerarin into puerarin-6″-O-phosphate. Under the optimum conditions, resting cells of B. cereus NT02 converted 27% of added 0.4 g/l puerarin into puerarin-6″-O-phosphate that was characterized by MS, ¹³C NMR, ³¹P NMR. The activity of puerarin-6″-O-phosphate was 25 times higher than that of puerarin in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging system. The water solubility of puerarin-6″-O-phosphate was 85.4 times higher than that of puerarin.