Figure 4. Determination of inhibition of VC and the theaflavins against AP.

The reaction mixtures comprise 10 μL AP buffer and 2 U AP in a final volume of 100 μL, DXP was added (final conc. 1 mM) to start the reaction. The reaction mixtures were incubated at 37 °C for 120 min and subsequently derivatized with DNPH and analyzed with the HPLC method. For VC assay, 2 mM VC was added before the addition of DXP. For assays of the theaflavins, the compounds were added separately before the addition of DXP (two concentrations, 20 and 500 μM for each compound were applied).