Fig. 4.

Chromatographic separation by UPLC-ESI-MS with monitoring at 430 nm (UPLC condition a). A: Human RPE/choroid (same chromatogram as in Fig. 2A). B: A synthetic sample derived from the incubation of alkyl ether lysoGPE(O-18:0/0:0) with all-trans-retinal. Peak 7 corresponds to the equivalent peaks in A and Fig. 2A. Peak 7 in the human RPE sample elutes at the same Rt as the synthetic alkyl ether lysoA2PE(O-18:0/0:0) (m/z 998.7) in B. Insets top and bottom: UV-visible absorbance and mass spectra corresponding to indicated peaks (arrows)