Fig. 3.

HPLC-DAD analysis of cell extract after incubation with β-apo-8′-carotenal. A: Representative HPLC-DAD chromatogram of the uptake of 1 μM of β-apo-8′-carotenal into fully differentiated Caco-2 cells after incubation at 37°C for 1 h. B: UV-vis spectra of β-apo-8′-carotenal and its cellular metabolites, the major one of which was confirmed as β-apo-8′-carotenoic acid (compound X) and the other we identified as 5,6-epoxy-β-apo-8′-carotenol (compound Y).