Redox mediated carbon monoxide release from a manganese carbonyl—implications for physiological CO delivery by CORMs

We evaluated the dynamics of hydrogen peroxide reactions with metal carbonyls. specifically a water-soluble manganese carbonyl. These files are the raw data for the quantitative mechanistic investigation of the H2O2 oxidation of the water-soluble model complex fac-[Mn(CO)3(Br)(bpCO2)]2–, (A, bpCO22– = 2,2’-bipyridine-4,4’-dicarboxylate dianion). The method of intial rates was utilized in the experimental studies thus raw spectral data for the figures and results presented in RSOS-211022 were included. These data demonstrated pH-dependent kinetics. All the raw absorbance data used to determine the initial reaction rates and observed rate constant from pH 6.1-7.4, 8-32 mM [H2O2]. and 19.5- 42oC are present. For soluble homogenous experiments, UV-Vis, Fluorescence assay, and FT-IR spectral data for conditions included in the manuscript. For insoluble products of the experiments, X-ray diffraction and ICP-AES raw data are included.

There are several untested hypotheses about the mechanisms of the reaction of manganese carbonyl with reactive oxygen species. We found that intracellular pH greatly influences the reaction rate and may be a control for redox-mediated CO release from mangense CORMs. Since the lysosome is more acidic and mitochondrial matrix is more basic than the cytosol it is likely different local rates of CO release would be observed. Furthermore, in considering the localization and diffusion of H2O2 in biological systems, it is likely that a relatively slow reaction with manganese carbonyls (compared to catalase) can exhibit physiological effects. The cytotoxic effects of Mn(I) carbonyls have been associated with the generation of hydroxyl radicals, however we founs no appreciable quantities of hydroxyl radicals compared to known catalysts. Thus we conclude that these cytotoxic effects are more likely due to released CO interacting with heme-proteins vital to cellular respiration. Our mechanistic and kinetic findings provide literature precedence for researchers examining physiological effects of Mn(I) carbonyls.

Methods
The data was collected using primarily UV-Vis scpectroscopy. Some of the data was collected using XRD, NMR, EPR, and IR spectroscopy; as well as GC-TCD and voltammetry.