Thiosulfate Ligands Research Articles

Adducts of bovine serum albumin and binuclear nitrosyl iron complex with thiosulfate ligands: a molecular docking and quantum chemical study

Adducts of bovine serum albumin and binuclear nitrosyl iron complex with thiosulfate ligands: a molecular docking and quantum chemical study

Effects of Nitrosyl Iron Complexes with Thiol, Phosphate, and Thiosulfate Ligands on Hemoglobin.

Nitrosyl iron complexes are remarkably multifactorial pharmacological agents. These compounds have been proven to be particularly effective in treating cardiovascular and oncological diseases. We evaluated and compared the antioxidant activity of tetranitrosyl iron complexes (TNICs) with thiosulfate ligands and dinitrosyl iron complexes (DNICs) with glutathione (DNIC-GS) or phosphate (DNIC-PO4-) ligands in hemoglobin-containing systems. The studied effects included the production of free radical intermediates during hemoglobin (Hb) oxidation by tert-butyl hydroperoxide, oxidative modification of Hb, and antioxidant properties of nitrosyl iron complexes. Measuring luminol chemiluminescence revealed that the antioxidant effect of TNICs was higher compared to DNIC-PO4-. DNIC-GS either did not exhibit antioxidant activity or exerted prooxidant effects at certain concentrations, which might have resulted from thiyl radical formation. TNICs and DNIC-PO4- efficiently protected the Hb heme group from decomposition by organic hydroperoxides. DNIC-GS did not exert any protective effects on the heme group; however, it abolished oxoferrylHb generation. TNICs inhibited the formation of Hb multimeric forms more efficiently than DNICs. Thus, TNICs had more pronounced antioxidant activity than DNICs in Hb-containing systems.

Development of a Peroral Dosage Form of a Nitrosyl Iron Complex with Thiosulfate Ligands, an Exogenous Nitric Oxide (NO) Donor

Development of a Peroral Dosage Form of a Nitrosyl Iron Complex with Thiosulfate Ligands, an Exogenous Nitric Oxide (NO) Donor

Effect of Nitrosyl Iron Complex with 3,4-Dichlorothiophenolyls on the Level of Cyclic Nucleotide In Vitro.

The effect of a promising NO donor, a binuclear nitrosyl iron complex (NIC) with 3,4-dichlorothiophenolyls [Fe2(SC6H3Cl2)2(NO)4], on the adenylate cyclase and soluble guanylate cyclase enzymatic systems was studied. In in vitro experiments, this complex increased the concentration of important secondary messengers, such as cAMP and cGMP. An increase of their level by 2.4 and 4.5 times, respectively, was detected at NIC concentration of 0.1 mM. The ligand of the complex, 3,4-dichlorothiophenol, produced a less pronounced effect on adenylate cyclase. It was shown that the effect of this complex on the activity of soluble guanylate cyclase was comparable to the effect of anionic nitrosyl complex with thiosulfate ligands that exhibits vasodilating and cardioprotective properties.

Nitrosyl iron complex with thiosulfate ligands: reaction with glutathione

Nitrosyl iron complex with thiosulfate ligands: reaction with glutathione

Influence of Nitrosyl Iron Complex with Thiosulfate Ligands on Therapeutically Important Targets Related to Type 2 Diabetes Mellitus.

The high prevalence of type 2 diabetes mellitus (T2DM), and the lack of effective therapy, determine the need for new treatment options. The present study is focused on the NO-donors drug class as effective antidiabetic agents. Since numerous biological systems are involved in the pathogenesis and progression of T2DM, the most promising approach to the development of effective drugs for the treatment of T2DM is the search for pharmacologically active compounds that are selective for a number of therapeutic targets for T2DM and its complications: oxidative stress, non-enzymatic protein glycation, polyol pathway. The nitrosyl iron complex with thiosulfate ligands was studied in this work. Binuclear iron nitrosyl complexes are synthetic analogues of [2Fe-2S] centers in the regulatory protein natural reservoirs of NO. Due to their ability to release NO without additional activation under physiological conditions, these compounds are of considerable interest for the development of potential drugs. The present study explores the effects of tetranitrosyl iron complex with thiosulfate ligands (TNIC-ThS) on T2DM and its complications regarding therapeutic targets in vitro, as well as its ability to bind liposomal membrane, inhibit lipid peroxidation (LPO), and non-enzymatic glycation of bovine serum albumin (BSA), as well as aldose reductase, the enzyme that catalyzes the reduction in glucose to sorbitol in the polyol pathway. Using the fluorescent probe method, it has been shown that TNIC-ThS molecules interact with both hydrophilic and hydrophobic regions of model membranes. TNIC-ThS inhibits lipid peroxidation, exhibiting antiradical activity due to releasing NO (IC50 = 21.5 ± 3.7 µM). TNIC-ThS was found to show non-competitive inhibition of aldose reductase with Ki value of 5.25 × 10-4 M. In addition, TNIC-ThS was shown to be an effective inhibitor of the process of non-enzymatic protein glycation in vitro (IC50 = 47.4 ± 7.6 µM). Thus, TNIC-ThS may be considered to contribute significantly to the treatment of T2DM and diabetic complications.

Organo-rhodium and -iridium complexes containing the thiosulfate (S2O32−) ligand

• Rhodium and iridium complexes of the thiosulfate (S 2 O 3 2- ) anion synthesised and characterised. • X-ray structure of (Ph 3 PCH 2 Ph) 2 [Rh 2 (μ-S 2 O 3 ) 2 (cod) 2 ] reported, confirming the presence of a Rh 2 S 2 core with S-bridging thiosulfates. • ESI mass spectrometry used to explore fragmentation of complexes in the gas phase. Reaction of the complexes [M 2 (μ -Cl) 2 (cod) 2 ] (M = Rh, Ir) with sodium thiosulfate pentahydrate gives the dinuclear thiosulfate complexes [M 2 (μ -S 2 O 3 ) 2 (cod) 2 ] 2- , which were isolated as their Ph 3 PCH 2 Ph + salts. An X-ray structure determination on the Rh complex confirms the dimeric nature of the complex, with the two Rh(I) centres bridged by the terminal sulfurs of the thiosulfate ligands. Using ESI mass spectrometry, the dimer [M 2 (μ -S 2 O 3 ) 2 (cod) 2 ] 2- and monomer [M(S 2 O 3 )(cod)] - are both observed, depending on the metal and capillary exit voltage. Reaction of sodium thiosulfate pentahydrate with the complexes trans -[RhCl(CX)(PPh 3 ) 2 ] (X = O or S) gave the anionic complexes Na[Rh(S 2 O 3 )(CX)(PPh 3 )], which were characterised by 31 P{ 1 H} NMR and IR spectroscopies, ESI MS, and in the case of the thiocarbonyl complex, by elemental analysis. Pentamethylcyclopentadienyl (Cp*) rhodium(III) and iridium(III) thiosulfate complexes [(Cp*M) 2 (μ -S 2 O 3 ) 3 ] 2- were also synthesised by reaction of the chloride-bridged dimers [Cp*MCl 2 ] 2 with sodium thiosulfate, and isolated as their Ph 3 PCH 2 Ph + salts. The complexes gave the expected parent dianions in ESI mass spectra, which underwent fragmentation of a thiosulfate ligand at higher capillary exit voltages to give ions [(Cp*M) 2 (S 2 O 3 ) 2 S + H] - .

Synthesis, structure and antibacterial activity of dinitrosyl iron complexes (DNICs) dimers functionalized with 5-(nitrophenyl) -4-H-1,2,4-triazole-3-thiolyls

Synthesis, electronic and crystal structures for new binuclear iron (1+) complexes of “µ-SCN-family” nitrosyl ferredoxins mimics with prospective antibacterial activity have been studied for the first time. This work aims at the synthesis and investigation of a new series of antibacterial agents, viz dimers of dinitrosyl iron complexes (DNICs) of [Fe 2 (SR) 2 (NO) 4 ] composition, where R is 5-(2-nitrophenyl)-4- H -1,2,4-triazole-3-thiolyl ( I ), 5-(3-nitrophenyl)-4- H -1,2,4-triazole-3-thiolyl ( II ), 5-(4-nitrophenyl)-4- H -1,2,4-triazole-3-thiolyl ( III ), that are nitric oxide (NO) donors, easily obtained by replacement of thiosulfate ligands in [Fe(S 2 O 3 ) 2 (NO) 2 ] 2- anion. Based on investigation of the structures of I and its isostructural analogs II and III (X-ray analysis, quantum-chemical calculations in the frame of DFT using NBO and QTAIM methods), data have been obtained on molecular interactions stabilizing DNIC dimer of µ–N–C–S structural type functionalized by 5-(2-nitrophenyl)-4- H -1,2,4-triazole-3-thiolyl. NBO calculations provided the assessment of bond energy for the Fe-S and Fe-N bonds incorporated in the µ–N–C–S bridge. From QTAIM analysis, detailed information on the nature and covalence of the forming bonds has been obtained. Assessment of antibacterial activity of I-III with respect to gram-negative ( Escherichia coli ) and gram-positive ( Micrococcus luteus ) bacteria has been performed.

The thiosulfate (S2O32−) ion; a neglected but simple hetero-donor ligand towards platinum(II), palladium(II) and nickel(II)

• Series of Pt(II), Pd(II) and Ni(II) complexes, including some cyclopalladated complexes, of the thiosulfate (S 2 O 3 2− ) anion synthesised and characterised. • The thiosulfate ligand coordinates through S and O in a bidentate chelating mode. • Fragmentation of the thiosulfate ligand was explored using ESI mass spectrometry. Reactions of the thiosulfate ligand (as sodium thiosulfate, Na 2 S 2 O 3 ·5H 2 O) with phosphine complexes of the group 10 metals Ni(II), Pd(II) and Pt(II) resulted in five neutral thiosulfate complexes, [Ni(S 2 O 3 )(dppe)] (dppe = Ph 2 PCH 2 CH 2 PPh 2 ), [Pd(S 2 O 3 )(dppe)], [Pd(S 2 O 3 )(dppf)] (dppf = Fe(C 5 H 4 PPh 2 ) 2 ), [Pd(S 2 O 3 )(PPh 3 ) 2 ] and [Pt(S 2 O 3 )(PPh 3 ) 2 ]. X-ray structure determinations of [Pd(S 2 O 3 )(dppf)], [Pd(S 2 O 3 )(PPh 3 ) 2 ] and [Pt(S 2 O 3 )(PPh 3 ) 2 ] confirmed that thiosulfate ligand coordinates as a bidentate chelating ligand via both sulfur and oxygen donor atoms. In addition, reactions of the thiosulfate ligand with dinuclear chloride-bridged cyclopalladated complexes gave four mononuclear anionic complexes [Pd(S 2 O 3 )(damp)] − (damp = N,N -dimethylbenzylamino, (CH 3 ) 2 NCH 2 C 6 H 4 ), [Pd(S 2 O 3 )(ptpy)] − (ptpy = p -tolylpyridyl), ]Pd(S 2 O 3 )(bzpy)] − (bzpy = 2-benzylpyridyl) and [Pd(S 2 O 3 ))pap)] − (pap = 2-(phenylazo)phenyl). The structure of (Ph 3 PCH 2 Ph)[Pd(S 2 O 3 )(pap)] by X-ray crystallography revealed the ability of thiosulfate ligand to cleave the bridging chloride ligand on the starting complexes by acting as an S,O -donor chelating ligand. An ESI mass spectrometric investigation showed that the coordinated thiosulfate ligand undergoes fragmentation at elevated capillary exit voltages.

Albumin as a prospective carrier of the nitrosyl iron complex with thiourea and thiosulfate ligands under aerobic conditions

The decomposition product of NICs with thiourea and thiosulfate ligands under aerobic conditions can form the high-molecular-weight product Fe(Cys34)(His39)(NO)(NO2).

Effects of albumin-bound nitrosyl iron complex with thiosulfate ligands on lipid peroxidation and activities of mitochondrial enzymes in vitro

Nitric oxide (NO) mediates diverse physiological processes in living organisms. Small molecular NO donors usually lack stability and have a short half-life in human tissues, limiting the therapeutic application. The anionic tetranitrosyl iron complex with thiosulfate ligands (TNIC) is one of the most promising NO donors. This study shows that bovine serum albumin (BSA) can effectively stabilize the TNIC complex under aerobic (physiological) conditions, which contributes to its prolonged action as NO donor. Our results demonstrated that TNIC-BSA inhibits formation of TBARS - standard biomarker for the lipid peroxidation induced oxidative stress. Also, it was found that TNIC-BSA inhibits the catalytic activity of mitochondrial membrane-bound enzymes: cytochrome c oxidase and monoamine oxidase A. Together, these results demonstrate that, stabilization of TNIC with BSA opens up the possibility of its practical application in chemotherapy of socially significant diseases.

Effect of embedded chalcogenide quantum dots in PbBr2 film on CsPbBr3 inorganic perovskite solar cells

Abstract Inorganic perovskite solar cells (PSCs) are considered prospective alternatives to organic PSCs due to their efficiency and relative stability. Cesium lead bromide (CsPbBr3) has a complete perovskite structure, is phase stable, exhibits a wide bandgap energy of 2.3 eV under operating conditions, and is regarded as a suitable material not only for stable PSCs, but also for semi-transparent PSCs. In this study, we synthesize Cu–Zn–In–S–Se (CZISSe) quantum dots (QDs) and demonstrate their novel use for improving the performance of PSC devices. QDs are embedded through ligand-exchange, which replaces long organic chains with thiosulfate (–S2O3) ligands and disperses the S2O3-capped QDs in the PbBr2 solution to prepare QD-blended precursor inks. The QDs promote the crystallization of CsPbBr3 and hole extraction from the photoactive layer. As a result, the optimized power conversion efficiency (PCE) of the QD-incorporated PSC is 5.37%, which is a 22.6% enhancement compared to those of the control devices. This work provides an effective and simple process for enhancing the performance of CsPbBr3-based PSCs.

Arrhenius Equation in Analysis of the Mechanism of Erythrocyte Hemolysis

The effect of temperature on the kinetics of erythrocyte hemolysis induced by tert-butyl hydroperoxide and dinitrosyl iron complex with thiosulfate ligands was studied. The inverse of the time needed to achieve 50% hemolysis was used as an estimate of the rate of hemolysis. This has afforded us an opportunity to present the obtained experimental data in the form of linear graphs of Arrhenius. The slope for tert-butyl hydroperoxide was 2.4 times higher. This means that erythrocyte hemolysis induced by tert-butyl hydroperoxide is more thermosensitive and, probably, proceeds through a different chemical mechanism. The hemolysis of red blood cells induced by tert-butyl hydroperoxide was preceded by a concentration-dependent increase in the level of thiobarbituric acid reactive substances the erythrocyte membranes, indicating the activation of lipid peroxidation. This effect was not observed in the case of dinitrosyl iron complex with thiosulfate ligands. This confirms the difference in the mechanisms of hemolytic action of tert-butyl hydroperoxide and dinitrosyl iron complexes and is consistent with the results of the analysis of the temperature dependences of the rate of hemolysis according to the Arrhenius equation.

Identification of the Products of the Reaction of Nitrosyl Iron Complexes with Phosphoenolpyruvic Acid by Mass Spectrometry

The reaction of the tetranitrosyl iron complex containing the thiosulfate ligand (TNIC) (NO donor) with phosphoenolpyruvic acid (PEP), which is one of the main biological macroergic compounds, was studied by mass spectrometry. The use of mass spectrometry made it possible to perform studies in an aqueous medium, separate the substances, and quantitatively correlate the peak intensities with the concentrations of the substances. The products of the reaction of PEP with TNIC were identified by IR spectroscopy and mass spectrometry. The reaction product was found to have a Fe–O–C bond. Among the reaction products, the ions with m/z = 318 and 256 belong to the compounds [O3S2–Fe–PEP]–2, and [S-Fe–PEP]–2, respectively.

Influence of hemoglobin and albumin on the NO donation effect of tetranitrosyl iron complex with thiosulfate

The effects of deoxyhemoglobin (Hb) and albumin on the NO-donor activity of the anionic tetranitrosyl iron complex with thiosulfate ligands (1) were studied for the first time. It was shown that Hb significantly stabilizes complex 1; in its presence, NO generation from the complex proceeds at a noticeably slower rate. A similar effect is observed when complex 1 is bound to albumin, in which case complex 1 decomposes 27 times slower than in the absence of albumin in the solution. The observed effects provide a prolonged action of complex 1 as NO-donor, which may enhance its potential pharmacological efficacy.

Antioxidant activity of tetra nitrosyl iron complex with thiosulfate ligands and its effect on catalytic activity of mitochondrial enzymes in vitro

The antioxidant and antiradical properties of the tetra nitrosyl iron complex with thiosulfate ligands (TNIC) in the mouse brain homogenates in vitro were also studied. It was found for the first time that TNIC is an effective antioxidant. The effect of TNIC on the catalytic activity of mitochondrial enzymes: cytochrome c oxidase and monoamine oxidase A has been studied. It was shown for the first time that TNIC is an inhibitor of the catalytic activity of cytochrome c oxidase and monoamine oxidase A in the brain mitochondria isolated from animals in vitro.

Antioxidant Activity of Tetranitrosyl Iron Complex with Thiosulfate Ligands and Its Effect on Catalytic Activity of Mitochondrial Enzymes In vitro.

The antioxidant and antiradical properties of the tetra nitrosyl iron complex with thiosulfate ligands (TNIC) were studied in vitro in mouse brain homogenates. It was found for the first time that TNIC is an effective antioxidant. The effect of TNIC on the catalytic activity of mitochondrial enzymes cytochrome c oxidase and monoamine oxidase A was studied. It was shown for the first time that TNIC is an inhibitor of the catalytic activity of cytochrome c oxidase and monoamine oxidase A in animal brain mitochondria in vitro.

Synthesis of Alkanethiolate-Capped Metal Nanoparticles Using Alkyl Thiosulfate Ligand Precursors: A Method to Generate Promising Reagents for Selective Catalysis.

Evaluation of metal nanoparticle catalysts functionalized with well-defined thiolate ligands can be potentially important because such systems can provide a spatial control in the reactivity and selectivity of catalysts. A synthetic method utilizing Bunte salts (sodium S-alkylthiosulfates) allows the formation of metal nanoparticles (Au, Ag, Pd, Pt, and Ir) capped with alkanethiolate ligands. The catalysis studies on Pd nanoparticles show a strong correlation between the surface ligand structure/composition and the catalytic activity and selectivity for the hydrogenation/isomerization of alkenes, dienes, trienes, and allylic alcohols. The high selectivity of Pd nanoparticles is driven by the controlled electronic properties of the Pd surface limiting the formation of Pd–alkene adducts (or intermediates) necessary for (additional) hydrogenation. The synthesis of water soluble Pd nanoparticles using ω-carboxylate-S-alkanethiosulfate salts is successfully achieved and these Pd nanoparticles are examined for the hydrogenation of various unsaturated compounds in both homogeneous and heterogeneous environments. Alkanethiolate-capped Pt nanoparticles are also successfully synthesized and further investigated for the hydrogenation of various alkynes to understand their geometric and electronic surface properties. The high catalytic activity of activated terminal alkynes, but the significantly low activity of internal alkynes and unactivated terminal alkynes, are observed for Pt nanoparticles.

Bis(4-nitrobenzenethiolato)tetranitrosyldiiron: synthesis, structure, and pharmacological activity of a new nitric oxide (NO) donor

A preparative procedure was developed for the synthesis of new binuclear tetranitrosyl iron complex of the “μ-S” structural type, [Fe2(SC6H4NO2)2(NO)4] (1), comprising the replacement of the thiosulfate ligands in Na2[Fe2(S2O3)2(NO)4]•4H2O by anions of the 4-nitrobenzenethiolate hydrazinium salt. The salt was obtained by the reduction of bis(4-nitrophenyl) disulfide with hydrazine hydrate in ethanol. The physicochemical properties of the complex in the solid state were studied by IR and Mossbauer spectroscopy. According to amperometric measurements in aqueous solutions, the complex generates NO in a protic medium without additional photo, thermal, or redox activation, providing prolonged release of NO, since the para-positioned nitro group in the aromatic ligand functions as an additional NO source. A study of the pharmacological activity by the MTT assay showed that the complex possesses a high cytotoxic activity against the MCF7 human breast cancer cells (IC50 = 47 μmol L–1) and an antibacterial activity against gram-negative (E. coli, BB strain) and gram-positive (M. luteus, 21/26 strain) microorganisms.

Investigation of the reaction between phosphoenolpyruvic acid and thiosulfate-nitrosyl iron complex

Reaction between the nitric oxide donor, tetranitrosyl iron complex with thiosulfate ligand (TNIC), and phosphoenolpyruvic acid (PEP) was studied. Formation of products of the reaction between PEP and TNIC was confirmed by UV-, IR-spectroscopy, and mass spectrometry methods. Also, ions with mass numbers m/z 318 and m/z 256 were identi-fied among the reaction products, belonging to the compounds [O3S2—Fe—PEP]2– and [S—Fe—PEP]2–, respectively.