biostudies-literatureSikora ANHLBI NIH HHSMedical Research Council856-67https://www.ebi.ac.uk/biostudies/studies/S-EPMC3700382biostudies-literatureUnknown26(6)Aromatic boronic acids react rapidly with peroxynitrite (ONOO(-)) to yield phenols as major products. This reaction was used to monitor ONOO(-) formation in cellular systems. Previously, we proposed that the reaction between ONOO(-) and arylboronates (PhB(OH)2) yields a phenolic product (major pathway) and a radical pair PhB(OH)2O(•-)···(•)NO2 (minor pathway). [Sikora, A. et al. (2011) Chem. Res. Toxicol. 24, 687-697]. In this study, we investigated the influence of a bulky triphenylphosphonium (TPP) group on the reaction between ONOO(-) and mitochondria-targeted arylboronate isomers (o-, m-, and p-MitoPhB(OH)2). Results from the electron paramagnetic resonance (EPR) spin-trapping experiments unequivocally showed the presence of a phenyl radical intermediate from meta and para isomers, andChemical research in toxicologyReaction between peroxynitrite and triphenylphosphonium-substituted arylboronic acid isomers: identification of diagnostic marker products and biological implications.PMC3700382R01 HL063119MC_U105663142Zielonka JDebski DJoseph JMurphy MPMichalowski BHartley RCSikora ADybala-Defratyka AKalyanaraman BAdamus JfalseReaction between peroxynitrite and triphenylphosphonium-substituted arylboronic acid isomers: identification of diagnostic marker products and biological implications.Aromatic boronic acids react rapidly with peroxynitrite (ONOO(-)) to yield phenols as major products. This reaction was used to monitor ONOO(-) formation in cellular systems. Previously, we proposed that the reaction between ONOO(-) and arylboronates (PhB(OH)2) yields a phenolic product (major pathway) and a radical pair PhB(OH)2O(•-)···(•)NO2 (minor pathway). [Sikora, A. et al. (2011) Chem. Res. Toxicol. 24, 687-697]. In this study, we investigated the influence of a bulky triphenylphosphonium (TPP) group on the reaction between ONOO(-) and mitochondria-targeted arylboronate isomers (o-, m-, and p-MitoPhB(OH)2). Results from the electron paramagnetic resonance (EPR) spin-trapping experiments unequivocally showed the presence of a phenyl radical intermediate from meta and para isomers, and2013-01-01T00:00:00Z2013 Jun2025-04-26T10:32:06.826Z2019-03-27T01:12:27ZS-EPMC37003822361133810.1021/tx300499c