Water-soluble diiron hexacarbonyl complex as a CO-RM: controllable CO-releasing, releasing mechanism and biocompatibility

Abstract

A water soluble diiron hexacarbonyl complex, [Fe2{μ-SCH2CH(OH)CH2(OH)}2(CO)6] (1), was synthesised by reacting thioglycol with Fe3(CO)12 in THF. This diiron complex was employed as carbon monoxide releasing molecule (CO-RM). The CO-releasing was initiated via substitution of the bound CO by cysteamine (CysA, a clinic medicine). Further decomposition of the substituted products led to at least partially the formation of monoiron(II) dicarbonyl species via oxidative process while releasing more CO under inert atmosphere. Three intermediates generated in the CO-releasing process were spectroscopically identified. The kinetics of the decomposition of complex 1 was first-order process for both the complex and CysA, respectively. Under open atmosphere, the CO-releasing mechanism altered due to the involvement of oxygen in the decomposition of complex 1. The system showed minimal cytotoxicity in two selected arbitrarily cell lines, QSG-7701 and HepG2, with IC50 at the scale of 100 μmol L(-1).

PhotoCORMs: CO release moves into the visible

“…Facilitating this solution may involve modification of the core molecule architecture with groups to promote this, such as alcohol functionality. 25 Such modification may lead to an increased mass of the pro-drug, which reduces the overall active content available.…”

“…Complexes similar in structure to 24 have been studied by Liu and co-workers as chemically-triggered CORMs. [25][26][27] Complexes of the form fac-[Re(bpy)(CO) 3 …”

“…Enzyme-triggered CORMs (ET-CORMs) make use of the presence of esterases in cells to bring about CO release at metal centres. [21][22][23][24] Triggering using small molecules is also possible, with the combination of a CORM with a second chemical agent [25][26][27] allowing temporal control of release. More exotic approaches have also been explored, for example release triggered by electromagnetic heating.…”

Introducing polyethyleneimine (PEI) into the electrospun fibrous membranes containing diiron mimics of [FeFe]-hydrogenase: Membrane electrodes and their electrocatalysis on proton reduction in aqueous media

“…One of the causes is probably that the amine N of PEI can react with the diiron mimics to replace the bound CO. In a mimicking system, such a substitution reaction can readily proceed [51]. Such substitution reactions will lead to complete decomposition of the diiron mimics at the end [51].…”

Gasotransmitter delivery via self-assembling peptides: Treating diseases with natural signaling gases

“…While recently reported iron-based CO donors suggest progress on this front [86,87], most studies on CO delivery are carried out using ruthenium and manganese-based donors. Efforts to evaluate the toxicity of common CORMs show mixed results.…”