Decroos, Christophe published the artcileToward Stable Electron Paramagnetic Resonance Oximetry Probes: Synthesis, Characterization, and Metabolic Evaluation of New Ester Derivatives of a Tris-(para-carboxyltetrathiaaryl)methyl (TAM) Radical, Computed Properties of 55788-44-8, the publication is Chemical Research in Toxicology (2013), 26(10), 1561-1569, database is CAplus and MEDLINE.
Tris-(p-carboxyltetrathiaaryl)-Me (TAM) radicals, such as 1a (“Finland” radical), are useful EPR probes for oximetry. However, they are rapidly metabolized by liver microsomes in the presence of NADPH, with the formation of diamagnetic quinone-methide metabolites resulting from an oxidative decarboxylation of one of their carboxylate substituents. In an effort to obtain TAM derivatives potentially more metabolically stable in vivo, the authors synthesized four new TAM radicals in which the carboxylate substituents of 1a have been replaced with esters groups bearing various alkyl chains designed to render them water-soluble The new compounds were completely characterized by UV-visible and EPR spectroscopies, high resolution mass spectrometry (HRMS), and electrochem. Two of them were water-soluble enough to undergo detailed microsomal metabolic studies in comparison with 1a. They are stable in the presence of the esterases present in rat liver microsomes and cytosol, and, contrary to 1a, stable to oxidation in the presence of NADPH-supplemented microsomes. A careful study of their possible microsomal reduction under anaerobic or aerobic conditions showed that they were more easily reduced than 1a, in agreement with their higher reduction potentials. They were reduced into the corresponding anions not only under anaerobic conditions but also in the presence of dioxygen. These anions were much more stable than that of 1a and could be characterized by UV-visible spectroscopy, MS, and at the level of their protonated product. However, they were oxidized by O2, giving back to the starting ester radicals and catalyzing a futile cycle of O2 reduction Such reactions should be considered in the design of future stable EPR probes for oximetry in vivo.
Chemical Research in Toxicology published new progress about 55788-44-8. 55788-44-8 belongs to bromides-buliding-blocks, auxiliary class Bromide,Salt,Aliphatic hydrocarbon chain,Aliphatic hydrocarbon chain, name is Sodium 3-bromopropane-1-sulfonate, and the molecular formula is C3H6BrNaO3S, Computed Properties of 55788-44-8.
Referemce:
https://en.wikipedia.org/wiki/Bromide,
bromide – Wiktionary