Chemoselective Stabilized\nTriphenylphosphonium Probes\nfor Capturing Reactive Carbonyl Species and Regenerating Covalent\nInhibitors with Acrylamide Warheads in Cellulo

Reactive carbonyl\nspecies (RCS) are important biomarkers\nof oxidative\nstress-related diseases because of their highly reactive electrophilic\nnature. Despite their potential as triggers for prodrug activation,\nselective labeling approaches for RCS remain limited. Here, we utilized\ntriphenylphosphonium groups to chemoselectively capture RCS via an\naqueous Wittig reaction, forming α,β-unsaturated carbonyls\nthat enable further functionalization. We first designed native (light)\nand deuterated (heavy) probes to facilitate RCS metabolomic identification\nthrough distinct MS isotope patterns. This approach allowed us to\ncapture and relatively quantify several endogenous RCS related to\nadvanced lipoxidation/glycation end products (ALEs/AGEs). Second,\nwe demonstrated that various endogenous RCS can trigger the in situ\ngeneration of acrylamide warheads of targeted covalent inhibitors\n(TCIs) with different substituents. These structural variations influence\ntheir protein binding profiles and consequently alter their cytotoxicity,\nwhich is beneficial for the development of inhibitor cocktails.