Figure 5. In the presence of the photostabilizer EHMC (yellow), UVR-induced isomerization of trans-resveratrol is strongly inhibited, although a small amount of the cis- isomer (green) is visible.

Figures 3, 4 and 5 are the relevant portions of the HPLC chromatograms recorded before irradiation with no EHMC, after 5 MED with no EHMC, and after 5 MED with 4% EHMC, respectively.