Extended Data Fig. 4: pH sensitive keto-enol tautomerization of piceol.

(a) The enol/keto ratio of piceol presented as LC-MS/MS chromatogram produced in reaction buffer with different pH environments. (b) The enol/keto ratio of 4HAP (produced in buffer with pH=8.5) incubated in the buffers with different pH for 2 h in room temperature.