Exogenous markers for the characterization of human diseases associated with oxidative stress

► Synthetic designed markers are described constructed from endogenous subunits. ► These subunits are tyrosine, linoleic acid and guanosine (or cholesterol). ► The subunits are connected covalently and under oxidative stress (OS) oxidized. ► Their oxidized form characterize the OS and analyzed by LC/MS. ► They were used in vitro, ex and in vivo: Parkinson, diabetics atherosclerosis.