Initially, the reaction buffer (100 mM Tris-HCl, 5 mM MgCl2, 0.5 mM DTT, pH 7.5) was added followed by the addition of 2 mM SAM and 5 μΜ of the enzyme. The reaction mixture was incubated in a thermomixer at 25 o C, 750 rpm. The respective substrate (1a-d) in a stock solution of DMSO (200 mM) was added in the appropriate volume to reach the final substrate concentration of 1 mM. Methylation of hydroxycinnamic acids was monitored by HPLC. However, confirmation of the methylation products through HPLC analysis was not possible due to the absence of authentic standards. The appearance of a second peak other than the peak of the confirmed starting material is assigned to the corresponding methylation product.