Search

Oxidative stress due to excess superoxide anion ($${{\bf{O}}}_{{\bf{2}}}^{{\boldsymbol{\cdot }}{\boldsymbol{-}}}$$ O 2 ⋅ − ) produced by dysfunctional mitochondria is a key pathogenic event of aging and ischemia-reperfusion diseases. Here, a new $${{\bf{O}}}_{{\bf{2}}}^{{\boldsymbol{\cdot }}{\boldsymbol{-}}}$$ O 2 ⋅ − -scavenging MnII complex with a new polyamino-polycarboxylate macrocycle (4,10-dimethyl-1,4,7,10-tetraazacyclododecane-1,7-diacetate) containing 2 quinoline units (MnQ2), designed to improve complex stability and cell permeability, was compared to parental MnII complex with methyls replacing quinolines (MnM2). MnQ2 was more stable than MnM2 (log K = 19.56(8) vs. 14.73(2) for the equilibrium Mn2+ + L2−, where L = Q2 and M2) due to the involvement of quinoline in metal binding and to the hydrophobic features of the ligand which improve metal desolvation upon complexation. As oxidative stress model, H9c2 rat cardiomyoblasts were subjected to hypoxia-reoxygenation. MnQ2 and MnM2 (10 μmol L−1) were added at reoxygenation for 1 or 2 h. The more lipophilic MnQ2 showed more rapid cell and mitochondrial penetration than MnM2. Both MnQ2 and MnM2 abated endogenous ROS and mitochondrial $${{\bf{O}}}_{{\bf{2}}}^{{\boldsymbol{\cdot }}{\boldsymbol{-}}}$$ O 2 ⋅ − , decreased cell lipid peroxidation, reduced mitochondrial dysfunction, in terms of efficiency of the respiratory chain and preservation of membrane potential (Δψ) and permeability, decreased the activation of pro-apoptotic caspases 9 and 3, and increased cell viability. Of note, MnQ2 was more effective than MnM2 to exert cytoprotective anti-oxidant effects in the short term. Compounds with redox-inert ZnII replacing the functional MnII were ineffective. This study provides clues which further our understanding of the structure-activity relationships of MnII-chelates and suggests that MnII-polyamino-polycarboxylate macrocycles could be developed as new anti-oxidant drugs.

The diffusion of type 2 diabetes (T2D) throughout the world represents one of the most important health problems of this century. Patients suffering from this disease can currently be treated with numerous oral anti-hyperglycaemic drugs, but none is capable of reproducing the physiological action of insulin and, in several cases, they induce severe side effects. Developing new anti-diabetic drugs remains one of the most urgent challenges of the pharmaceutical industry. Multi-target drugs could offer new therapeutic opportunities for the treatment of T2D, and the reported data on type 2 diabetic mice models indicate that these drugs could be more effective and have fewer side effects than mono-target drugs. α-Glucosidases and Protein Tyrosine Phosphatase 1B (PTP1B) are considered important targets for the treatment of T2D: the first digest oligo- and disaccharides in the gut, while the latter regulates the insulin-signaling pathway. With the aim of generating new drugs able to target both enzymes, we synthesized a series of bifunctional compounds bearing both a nitro aromatic group and an iminosugar moiety. The results of tests carried out both in vitro and in a cell-based model, show that these bifunctional compounds maintain activity on both target enzymes and, more importantly, show a good insulin-mimetic activity, increasing phosphorylation levels of Akt in the absence of insulin stimulation. These compounds could be used to develop a new generation of anti-hyperglycemic drugs useful for the treatment of patients affected by T2D.

Three pseudohalide analogues of the established gold drug auranofin (AF hereafter), of general formula Au(PEt3)X, i.e. Au(PEt3)CN, Au(PEt3)SCN and Au(PEt3)N3 (respectively denoted as AFCN, AFSCN and AFN3), were prepared and characterized. The crystal structure was solved for Au(PEt3)SCN highlighting the classical linear geometry of the 2-coordinate gold(I) center. The solution behaviour of the compounds was then comparatively analysed through 31PNMR providing evidence for an acceptable stability under physiological-like conditions. Afterward, the reaction of these gold compounds with bovine serum albumin (BSA) and consequent adduct formation was investigated by 31PNMR. For all the studied gold compounds, the [Au(PEt3)]+ moiety was identified as the reactive species in metal/protein adducts formation. The cytotoxic effects of the complexes were subsequently measured in comparison to AF against a representative colorectal cancer cell line and found to be still relevant and roughly similar in the three cases though far weaker than those of AF. These results show that the nature of the anionic ligand can modulate importantly the pharmacological action of the gold-triethylphosphine moiety, affecting the cytotoxic potency. These aspects may be further explored to improve the pharmacological profiles of this family of metal complexes.

The study of metal-based drugs represents an important branch of modern bioinorganic chemistry. The growing importance of this field is linked to the large success in medicine of a few metal based drugs, either in clinical use or still experimental. Moreover, these metal-based drugs are frequently used as reference compounds to assess comparatively the behavior of newly synthesized metallodrugs. For the convenience of researchers working in this area we report here a compilation of the relevant analytical and spectroscopic data of ten representative metallodrugs based on Platinum, Ruthenium, Gold and Mercury. The selected compounds, namely Cisplatin, Oxaliplatin, Carboplatin, Auranofin, Sodium Aurothiomalate, NAMI-A, KP1019, Thimerosal, Merbromin and Phenylmercury Acetate, were chosen owing to their importance in the field. We believe that this compilation may turn very helpful to researchers as these data are difficult to find and generally scattered over a large number of (old) publications.

Oxidative stress due to excess superoxide anion (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\bf{O}}}_{{\bf{2}}}^{{\boldsymbol{\cdot }}{\boldsymbol{-}}}$$\end{document}O2⋅−) produced by dysfunctional mitochondria is a key pathogenic event of aging and ischemia-reperfusion diseases. Here, a new \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\bf{O}}}_{{\bf{2}}}^{{\boldsymbol{\cdot }}{\boldsymbol{-}}}$$\end{document}O2⋅−-scavenging MnII complex with a new polyamino-polycarboxylate macrocycle (4,10-dimethyl-1,4,7,10-tetraazacyclododecane-1,7-diacetate) containing 2 quinoline units (MnQ2), designed to improve complex stability and cell permeability, was compared to parental MnII complex with methyls replacing quinolines (MnM2). MnQ2 was more stable than MnM2 (log K = 19.56(8) vs. 14.73(2) for the equilibrium Mn2+ + L2−, where L = Q2 and M2) due to the involvement of quinoline in metal binding and to the hydrophobic features of the ligand which improve metal desolvation upon complexation. As oxidative stress model, H9c2 rat cardiomyoblasts were subjected to hypoxia-reoxygenation. MnQ2 and MnM2 (10 μmol L−1) were added at reoxygenation for 1 or 2 h. The more lipophilic MnQ2 showed more rapid cell and mitochondrial penetration than MnM2. Both MnQ2 and MnM2 abated endogenous ROS and mitochondrial \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\bf{O}}}_{{\bf{2}}}^{{\boldsymbol{\cdot }}{\boldsymbol{-}}}$$\end{document}O2⋅−, decreased cell lipid peroxidation, reduced mitochondrial dysfunction, in terms of efficiency of the respiratory chain and preservation of membrane potential (Δψ) and permeability, decreased the activation of pro-apoptotic caspases 9 and 3, and increased cell viability. Of note, MnQ2 was more effective than MnM2 to exert cytoprotective anti-oxidant effects in the short term. Compounds with redox-inert ZnII replacing the functional MnII were ineffective. This study provides clues which further our understanding of the structure-activity relationships of MnII-chelates and suggests that MnII-polyamino-polycarboxylate macrocycles could be developed as new anti-oxidant drugs.

The silver(I) N-heterocyclic carbene (NHC) complex bis(1-(anthracen-9-ylmethyl)-3-ethylimidazol-2-ylidene) silver chloride ([Ag(EIA)2 ]Cl), bearing two anthracenyl fluorescent probes, has been synthesized and characterized. [Ag(EIA)2 ]Cl is stable in organic solvents and under physiological conditions, and shows potent cytotoxic effects in vitro toward human SH-SY5Y neuroblastoma cells. The interactions of [Ag(EIA)2 ]Cl with a few model biological targets have been studied as well as its ability to be internalized in cells. The in vitro anticancer activity is apparently related to the level of drug internalization. Notably, [Ag(EIA)2 ]Cl does not react with a few model proteins, but is capable of binding the C-terminal dodecapeptide of thioredoxin reductase hTrxR(488-499) and to strongly inhibit the activity of this enzyme. Binding occurs through an unconventional process leading to covalent binding of one or two carbene ligands to the C-terminal dodecapeptide with concomitant release of the silver cation. To the best of our knowledge, this mode of interaction is reported here for the first time for Ag(NHC)2 complexes.