The reducing ability of EEMT and its reference compounds were determined in comparison with ascorbic acid as shown in Fig. 2B and Table 2.
In the range of 10–50 µg/ml, EEMT exhibits reducing effect that increased with increasing extract concentrations, the reducing capacity of EEMT at 50 µg/ml was equivalent to 13.2 µg/ml of ascorbic acid. Further, the reducing activities of the five polyphenols in EEMT are shown in Table 2.
At the concentration of 50 µg/ml, maclurin and morin exhibited superior reducing power to the other three reference components. Since these two compounds were the major polyphenols in EEMT, they should account for the high reduction activity of EEMT.