a, Characteristic BME-EFOX fragmentation pattern derived from the EPI of BME-EFOX-D5. b, EFOX-D5 levels in activated RAW264.7 cells grown for 3 days in medium supplemented with the indicated FA. ND indicates not detectable. c, Diagram of NaBH4 reaction. d, MRM scans monitoring for the m/z transitions 343.2/299.2 (13-EFOX-D5/loss of CO2; upper and middle panel) and 345.2/327.2 (hydroxy-DPA/loss of H2O; lower panel) in RAW264.7 cell lysates purified for EFOX-D5 ± NaBH4. e, MS/MS fragmentation of EFOX-D5 purified from activated RAW 264.7 cells and reduced with NaBH4.