Site-Specific Photochemical Reaction for Improved C=C Location Analysis of Unsaturated Lipids by Ultraviolet Photodissociation
Profiles of unsaturated PCs and corresponding photoproducts of the bovine liver polar extract (a) before and (b) after PB reaction with 4-CF3-Bzp for 10 s. The PB products are annotated with “PBPC.” Zoomed-in spectra over the range of 782–790 and 1031.5–1039.5 were shown in insets. All the labeled peaks were assigned as protonated PC lipids or photoproducts. UVPD MS/MS spectra of photoproducts of (c) PC 36 : 4 and (d) PC 34 : 1 at 260 nm and (e) PE 32 : 1 at 225 nm, as well as (f) PG 34 : 1 at 210 nm after 2 pulses. indicates the site(s) of unsaturation in the acyl chain, but the C=C geometry (viz cis/trans) is unknown.