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A new biphenol-dipicolylamine based ligand and its dinuclear Zn 2+ complex as fluorescent sensors for ibuprofen and ketoprofen in aqueous solution. Dalton Trans 2024. [PMID: 38767612 DOI: 10.1039/d4dt00935e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
In this work, the study of the new ligand 3,3'-bis[N,N-bis(pyridine-2-ylmethyl)aminomethyl]-2,2'-dihydroxybiphenyl (L) is reported, where a central 2,2'-biphenol (BPH) fluorophore was functionalized at 3,3'-positions with two dipicolylamine (DPA) side arms as receptor units. Following the synthesis and full chemical-physical characterization, the acid-base and Zn2+-coordination abilities of L were investigated through a combination of potentiometric, UV-Vis, fluorescence, NMR, XRD and DFT measurements. The optical properties of the ligand turned out to be strongly dependent on the pH, being straightforwardly associated with the protonation state of the BPH moiety, whereas its peculiar design allowed to form stable mono and dinuclear Zn2+ complexes. In the latter species, the presence of two Zn2+ ions coordinatively unsaturated and placed at close distance to each other, prompted us to test their usefulness as metallo-receptors for two environmental pollutants of great relevance, ibuprofen and ketoprofen. Potentiometric and fluorescence investigations evidenced that these important non-steroidal anti-inflammatory drugs (NSAIDs) are effectively coordinated by the metallo-receptors and, of relevance, both the stability and the fluorescence properties of the resulting ternary adducts are markedly affected by the different chemical architectures of the two substrates. This study aims at highlighting the promising perspectives arising from the use of polyamino phenolic ligands as chemosensors for H+/Zn2+ and other additional anionic targets in their metal-complexed forms.
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Photosensitizers Based on Bichromophoric Dyads Combining Ru(II)-Polypyridyl Complexes and Dissymmetric Perylene Monoimide Derivatives: The Nontrivial Role of Ligand Substitution. Inorg Chem 2024; 63:6248-6259. [PMID: 38533555 DOI: 10.1021/acs.inorgchem.3c04569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
The covalent modification of Ru(II) polypyridyl complexes (RPCs) with organic chromophores is a powerful strategy to obtain metal-based photosensitizer agents (PSs) with improved performance for application in photodynamic therapy (PDT). In this respect, perylene-imides are of particular interest due to their rich chemical-physical repertoire, and it is therefore quite surprising that their combination with RPCs has been poorly considered so far. Herein, we report on the photophysical behavior of two newly synthesized RPCs bearing a perylene monoimide appendant (PMI-Ad). Differently from the majority of RPCs-perylene-imides dyads, these chromophores are dissymmetric and are tethered to the metal centers through a single C-C bond in the 3- or 5-position of 1,10-phenanthroline (Ru-3PMI-Ad and Ru-5PMI-Ad). Both compounds show excellent singlet oxygen photosensitizing activity, with quantum yields reaching >90% in the case of Ru-3PMI-Ad. A combined spectroscopic and theoretical analysis, also involving transient absorption and luminescence lifetime measurements, demonstrates that both compounds undergo intersystem crossing on a very fast time scale (tens of picoseconds) and with high efficiency. Our results further demonstrate that the increased electron delocalization between the metal center and the PMI-Ad chromophore observed for Ru-3PMI-Ad additionally contributes to increase the singlet oxygen quantum yields by prolonging the lifetime of the triplet state.
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Ruthenium(II) Polypyridyl Complexes and Metronidazole Derivatives: A Powerful Combination in the Design of Photoresponsive Antibacterial Agents Effective under Hypoxic Conditions. Inorg Chem 2023; 62:7716-7727. [PMID: 37163381 DOI: 10.1021/acs.inorgchem.3c00214] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Ruthenium(II) polypyridyl complexes (RPCs) are gaining momentum in photoactivated chemotherapy (PACT), thanks to the possibility of overcoming the classical reliance on molecular oxygen of photodynamic therapy while preserving the selective drug activation by using light. However, notwithstanding the intriguing perspectives, the translation of such an approach in the development of new antimicrobials has been only barely considered. Herein, MTZH-1 and MTZH-2, two novel analogues of metronidazole (MTZ), a mainstay drug in the treatment of anaerobic bacterial infections, were designed and inserted in the strained ruthenium complexes [Ru(tpy)(dmp)(MTZ-1)]PF6 (Ru2) and [Ru(tpy)(dmp)(MTZ-2)]PF6 (Ru3) (tpy = terpyridine, dmp = 2,9-dimethyl-1,10-phenanthroline) (Chart 1). Analogously to the parental compound [Ru(tpy)(dmp)(5NIM)]PF6 (Ru1) (5-nitroimidazolate), the Ru(II)-imidazolate coordination of MTZ derivatives resulted in promising Ru(II) photocages, capable to easily unleash the bioactive ligands upon light irradiation and increase the antibacterial activity against Bacillus subtilis, which was chosen as a model of Gram-positive bacteria. The photoreleased 5-nitroimidazole-based ligands led to remarkable phototoxicities under hypoxic conditions (<1% O2), with the lead compound Ru3 that exhibited the highest potency across the series, being comparable to the one of the clinical drug MTZ. Besides, the chemical architectures of MTZ derivatives made their interaction with NimAunfavorable, being NimA a model of reductases responsible for bacterial resistance against 5-nitroimidazole-based antibiotics, thus hinting at their possible use to combat antimicrobial resistance. This work may therefore provide fundamental knowledge in the design of novel photoresponsive tools to be used in the fight against infectious diseases. For the first time, the effectiveness of the "photorelease antimicrobial therapy" under therapeutically relevant hypoxic conditions was demonstrated.
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A New Family of Macrocyclic Polyamino Biphenolic Ligands: Acid-Base Study, Zn(II) Coordination and Glyphosate/AMPA Binding. Molecules 2023; 28:molecules28052031. [PMID: 36903278 PMCID: PMC10003900 DOI: 10.3390/molecules28052031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/16/2023] [Accepted: 02/17/2023] [Indexed: 02/25/2023] Open
Abstract
In this study, the ligands 23,24-dihydroxy-3,6,9,12-tetraazatricyclo[17.3.1.1(14,18)]eicosatetra-1(23),14,16,18(24),19,21-hexaene, L1, and 26,27-dihidroxy-3,6,9,12,15-pentaazatricyclo[20.3.1.1(17,21)]eicosaepta-1(26),17,19,21(27),22,24-hexaene, L2, were synthesized: they represent a new class of molecules containing a biphenol unit inserted into a macrocyclic polyamine fragment. The previously synthesized L2 is obtained herein with a more advantageous procedure. The acid-base and Zn(II)-binding properties of L1 and L2 were investigated through potentiometric, UV-Vis, and fluorescence studies, revealing their possible use as chemosensors of H+ and Zn(II). The new peculiar design of L1 and L2 afforded the formation in an aqueous solution of stable Zn(II) mono (LogK 12.14 and 12.98 for L1 and L2, respectively) and dinuclear (LogK 10.16 for L2) complexes, which can be in turn exploited as metallo-receptors for the binding of external guests, such as the popular herbicide glyphosate (N-(phosphonomethyl)glycine, PMG) and its primary metabolite, the aminomethylphosphonic acid (AMPA). Potentiometric studies revealed that PMG forms more stable complexes than AMPA with both L1- and L2-Zn(II) complexes, moreover PMG showed higher affinity for L2 than for L1. Fluorescence studies showed instead that the L1-Zn(II) complex could signal the presence of AMPA through a partial quenching of the fluorescence emission. These studies unveiled therefore the utility of polyamino-phenolic ligands in the design of promising metallo-receptors for elusive environmental targets.
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Characterization of a Ruthenium(II) Complex in Singlet Oxygen-Mediated Photoelectrochemical Sensing. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:679-689. [PMID: 36574357 PMCID: PMC9835978 DOI: 10.1021/acs.langmuir.2c03042] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/13/2022] [Indexed: 06/17/2023]
Abstract
A water-soluble ruthenium(II) complex (L), capable of producing singlet oxygen (1O2) when irradiated with visible light, was used to modify the surface of an indium-tin oxide (ITO) electrode decorated with a nanostructured layer of TiO2 (TiO2/ITO). Singlet oxygen triggers the appearance of a cathodic photocurrent when the electrode is illuminated and biased at a proper reduction potential value. The L/TiO2/ITO electrode was first characterized with cyclic voltammetry, impedance spectroscopy, NMR, and Raman spectroscopy. The rate constant of singlet oxygen production was evaluated by spectrophotometric measurements. Taking advantage of the oxidative process initiated by 1O2, the analysis of phenolic compounds was accomplished. Particularly, the 1O2-driven oxidation of hydroquinone (HQ) produced quinone moieties, which could be reduced back at the electrode surface, biased at -0.3 V vs Ag/AgCl. Such a light-actuated redox cycle produced a photocurrent dependent on the concentration of HQ in solution, exhibiting a limit of detection (LOD) of 0.3 μmol dm-3. The L/TiO2/ITO platform was also evaluated for the analysis of p-aminophenol, a commonly used reagent in affinity sensing based on alkaline phosphatase.
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Ruthenium(II) Polypyridyl Complexes with π‑Expansive Ligands: Synthesis and Cubosome Encapsulation for Photodynamic Therapy of Non-Melanoma Skin Cancer. Inorg Chem Front 2023. [DOI: 10.1039/d2qi02678c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Abstract
In photodynamic therapy (PDT), Ru(II) polypyridyl complexes (RPCs) featuring the popular π-expansive benzo[i]dipyrido[3,2-a:2′,3′-c]phenazine (dppn) ligand have attracted much attention, mainly due to the good singlet oxygen sensitizing properties imparted by...
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Ferritin nanocomposites for the selective delivery of photosensitizing ruthenium-polypyridyl compounds to cancer cells. Inorg Chem Front 2022. [DOI: 10.1039/d1qi01268a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Human ferritin platforms containing Ru(ii)-polypyridyl-based photosensitizers effectively target cancer cells and provide cytotoxic effects upon light-activation.
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Nitroimidazole-Based Ruthenium(II) Complexes: Playing with Structural Parameters to Design Photostable and Light-Responsive Antibacterial Agents. Inorg Chem 2021; 61:6689-6694. [PMID: 34793162 DOI: 10.1021/acs.inorgchem.1c03032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
5-Nitroimidazole (5NIMH), chosen as a molecular model of nitroimidazole derivatives, which represent a broad-spectrum class of antimicrobials, was incorporated into the ruthenium complexes [Ru(tpy)(phen)(5NIM)]PF6 (1) and [Ru(tpy)(dmp)(5NIM)]PF6 (2) (tpy = terpyridine, phen = phenanthroline, dmp = 2,9-dimethyl-1,10-phenanthroline). Besides the uncommon metal coordination of 5-nitroimidazole in its imidazolate form (5NIM), the different architectures of the spectator ligands (phen and dmp) were exploited to tune the "mode of action" of the resulting complexes, passing from a photostable compound where the redox properties of 5NIMH are preserved (1) to one suitable for the nitroimidazole phototriggered release (2) and whose antibacterial activity against B. subtilis, chosen as cellular model, is effectively improved upon light exposure. This study may provide a fundamental knowledge on the use of Ru(II)-polypyridyl complexes to incorporate and/or photorelease biologically relevant nitroimidazole derivatives in the design of a novel class of antimicrobials.
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Ibuprofen as linker for calcium(II) in a 1D-coordination polymer: A solid state investigation complemented with solution studies. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2021.120319] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Exploring the potential of highly charged Ru(II)- and heteronuclear Ru(II)/Cu(II)-polypyridyl complexes as antimicrobial agents. J Inorg Biochem 2021; 220:111467. [PMID: 33932708 DOI: 10.1016/j.jinorgbio.2021.111467] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/29/2021] [Accepted: 04/18/2021] [Indexed: 01/18/2023]
Abstract
The antimicrobial potential of two ruthenium(II) polypyridyl complexes, [Ru(phen)2L1]2+ and [Ru(phen)2L2]2+ (phen = 1,10-phenanthroline) containing the 4,4'-(2,5,8,11,14-pentaaza[15])-2,2'-bipyridilophane (L1) and the 4,4'-bis-[methylen-(1,4,7,10-tetraazacyclododecane)]-2,2' bipyridine (L2) units, is herein investigated. These peculiar polyamine frameworks afford the formation of highly charged species in solution, influence the DNA-binding and cleavage properties of compounds, but they do not undermine their singlet oxygen sensitizing capacities, thus making these complexes attractive 1O2 generators in aqueous solution. L1 and L2 also permit to stably host Fenton -active Cu2+ ion/s, leading to the formation of mixed Ru2+/Cu2+ forms capable to further strengthen the oxidative damages to biological targets. Herein, following a characterization of the Cu2+ binding ability by [Ru(phen)2L2]2+, the water-octanol distribution coefficients, the DNA binding, cleavage and 1O2 sensitizing properties of [Ru(phen)2L2]2+ and [Cu2Ru(phen)2L2]6+ were analysed and compared with those of [Ru(phen)2L1]2+ and [CuRu(phen)2L1]4+. The antimicrobial activity of all compounds was evaluated against B. subtilis, chosen as a model for gram-positive bacteria, both under dark and upon light-activation. Our results unveil a notable phototoxicity of [Ru(phen)2L2]2+ and [Cu2Ru(phen)2L2]6+, with MIC (minimal inhibitory concentrations) values of 3.12 μM. This study highlights that the structural characteristics of polyamine ligands gathered on highly charged Ru(II)-polypyridyl complexes are versatile tools that can be exploited to achieve enhanced antibacterial strategies.
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Switching on the Fluorescence Emission of Polypyridine Ligands by Simultaneous Zinc(II) Binding and Protonation. Chempluschem 2020; 85:659-671. [PMID: 32237220 DOI: 10.1002/cplu.201900752] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/11/2020] [Indexed: 11/07/2022]
Abstract
The synthesis and characterization of the two new open-chain ligands 1,15-bis-[6-(2,2'-bipyridyl)]-2,5,8,11,14-pentaaza-octadecane (L1) and 1,15-bis-[2-(1,10-phenanthroline)-9-methyl]-2,5,8,11,14-pentaazaoctadecane (L2), both featuring a tetraethylenpentaamine chain linking via methylene bridges the 6 and 2 positions of two identical 2,2'-bipyridyl (bpy) and 9-methyl-1,10-phenanthroline (9-methyl-phen) moieties respectively, are reported. Their protonation and binding ability for Cu2+ , Zn2+ , Cd2+ and Pb2+ have been studied by coupling potentiometric titrations with UV-vis absorption and fluorescence emission measurements in water. L1 and L2 afford stable mono- and dinuclear complexes, in which the metal ion is bound by a single bpy or 9-methyl-phen unit and the amine groups on the aliphatic chain. However, L1 displays a greater binding ability for Cu2+ and Zn2+ with respect to L2, the stability constants of the [ML1]2+ complexes being 21.8 (Cu2+ ) and 19.4 (Zn2+ ) log units vs 20.34 and 16.8 log. units for the corresponding L2 species. Among all the metal ions tested, only the Zn2+ complex with L2 features an enhanced fluorescence emission at neutral pH, thanks to the simultaneous binding of one Zn2+ ion and H+ ion(s), that inhibits any possible photoinduced electron transfer (PET) process from the amine donors to the excited phen moiety. Binding of a second metal switches off the emission again.
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Playing with Structural Parameters: Synthesis and Characterization of Two New Maltol-Based Ligands with Binding and Antineoplastic Properties. Molecules 2020; 25:molecules25040943. [PMID: 32093219 PMCID: PMC7070877 DOI: 10.3390/molecules25040943] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 02/11/2020] [Accepted: 02/14/2020] [Indexed: 11/30/2022] Open
Abstract
Two maltol-based ligands, N,N′-bis((3-hydroxy-4-pyron-2-yl)methyl)-1,4-piperazine (L1) and N,N′,N′-tris((3-hydroxy-4-pyron-2-yl)methyl)-N-methylethylendiamine (L2), were synthesized and characterized. L1 and L2, containing, respectively, two and three maltol units spaced by a diamine fragment, were designed to evaluate how biological and binding features are affected by structural modifications of the parent compound malten. The acid-base behavior and the binding properties towards transition, alkaline-earth (AE) and rare-earth (RE) cations in aqueous solution, studied by potentiometric, UV-Vis and NMR analysis, are reported along with biological studies on DNA and leukemia cells. Both ligands form stable complexes with Cu(II), Zn(II) and Co(II) that were studied as metallo-receptors for AE and RE at neutral pH. L1 complexes are more affected than L2 ones by hard cations, the L1-Cu(II) system being deeply affected by RE. The structural modifications altered the mechanism of action: L1 partially maintains the ability to induce structural alterations of DNA, while L2 provokes single strand (nicks) and to a lesser extent double strand breaks of DNA.
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Different Antioxidant Efficacy of Two Mn II-Containing Superoxide Anion Scavengers on Hypoxia/Reoxygenation-Exposed Cardiac Muscle Cells. Sci Rep 2019; 9:10320. [PMID: 31311943 PMCID: PMC6635543 DOI: 10.1038/s41598-019-46476-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 06/28/2019] [Indexed: 01/02/2023] Open
Abstract
Oxidative stress due to excess superoxide anion (\documentclass[12pt]{minimal}
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\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}
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\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}
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\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.
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Cover Feature: Highly Charged Ruthenium(II) Polypyridyl Complexes as Effective Photosensitizer in Photodynamic Therapy (Chem. Eur. J. 45/2019). Chemistry 2019. [DOI: 10.1002/chem.201902431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Highly Charged Ruthenium(II) Polypyridyl Complexes as Effective Photosensitizer in Photodynamic Therapy. Chemistry 2019; 25:10606-10615. [PMID: 31107567 DOI: 10.1002/chem.201901570] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Indexed: 11/12/2022]
Abstract
A comparative study between two novel, highly water soluble, ruthenium(II) polypyridyl complexes, [Ru(phen)2 L'] and [Ru(phen)2 Cu(II)L'] (L and L-CuII ), containing the polyaazamacrocyclic unit 4,4'-(2,5,8,11,14-pentaaza[15])-2,2'-bipyridilophane (L'), is herein reported. L and L-CuII interact with calf-thymus DNA and efficiently cleave DNA plasmid when light-activated. They also possess great penetration abilities and photo-induced biological activities, evaluated on an A375 human melanoma cell line, with L-CuII being the most effective. Our study highlights the key role of the Fenton active CuII center within the macrocycle framework, that would play a synergistic role with light activation in the formation of cytotoxic ROS species. Based on these results, an optimal design of RuII polypyridyl systems featuring specific CuII -chelating polyamine units could represent a suitable strategy for the development of novel and effective photosensitizers in photodynamic therapy.
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Spectroscopic and photoacoustic characterization of encapsulated iron oxide super-paramagnetic nanoparticles as a new multiplatform contrast agent. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 199:248-253. [PMID: 29626815 DOI: 10.1016/j.saa.2018.03.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 03/09/2018] [Accepted: 03/10/2018] [Indexed: 05/24/2023]
Abstract
Recently, a number of photoacoustic (PA) agents with increased tissue penetration and fine spatial resolution have been developed for molecular imaging and mapping of pathophysiological features at the molecular level. Here, we present bio-conjugated near-infrared light-absorbing magnetic nanoparticles as a new agent for PA imaging. These nanoparticles exhibit suitable absorption in the near-infrared region, with good photoacoustic signal generation efficiency and high photo-stability. Furthermore, these encapsulated iron oxide nanoparticles exhibit strong super-paramagnetic behavior and nuclear relaxivities that make them useful as magnetic resonance imaging (MRI) contrast media as well. Their simple bio-conjugation strategy, optical and chemical stability, and straightforward manipulation could enable the development of a PA probe with magnetic and spectroscopic properties suitable for in vitro and in vivo real-time imaging of relevant biological targets.
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Optical and Electrochemical Study of Acridine-Based Polyaza Ligands for Anion Sensing. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800298] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Myelin-specific T cells carry and release magnetite PGLA–PEG COOH nanoparticles in the mouse central nervous system. RSC Adv 2018; 8:904-913. [PMID: 35538965 PMCID: PMC9076978 DOI: 10.1039/c7ra11290d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 12/13/2017] [Indexed: 11/21/2022] Open
Abstract
Progress in nanotechnology has determined new strategies concerning drug delivery into the central nervous system for the treatment of degenerative and inflammatory diseases. To date, brain targeting through systemic drug administration, even in a nano-composition, is often unsuccessful. Therefore, we investigated the possibility of loading T lymphocytes with PGLA–PEG COOH magnetite nanoparticles (30 nm), which can be built up to easily bind drugs and monoclonal antibodies, and to exploit the ability of activated T cells to cross the blood–brain barrier and infiltrate the brain parenchyma. Iron oxide nanoparticles have been widely used in biomedical applications due to their theranostic properties and are therefore a well-established nanomaterial. The magnetite core is easily hybridized with polymeric compounds that may enhance the possibility of the nanoparticles entering cells with low phagocytic properties. Taking advantage of these material characteristics, after in vitro assessment of the viability and functionality of nano-loaded MOG35–55 specific T cells, we transferred cells containing the nano-cargo into naïve mice affected by experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis. By means of histological and immunohistological methods, we were able to identify the nano-loaded T cells in the central nervous system. Our data demonstrated that T cells containing nanomaterials hold the possibility of carrying and releasing nanoparticles in the brain. Magnetite nanoparticles enter non-phagocytic myelin-specific T cells and reach the central nervous system after in vivo transfer.![]()
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Methylene blue-containing liposomes as new photodynamic anti-bacterial agents. J Mater Chem B 2017; 5:2788-2797. [DOI: 10.1039/c6tb03367a] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Novel cationic liposomes containing the photo-activatable drug methylene blue (MB) strongly enhance the antibacterial activity of MB towards Gram-negative bacteria and improve biofilm penetration.
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Di- and Triphosphate Recognition and Sensing with Mono- and Dinuclear Fluorescent Zinc(II) Complexes: Clues for the Design of Selective Chemosensors for Anions in Aqueous Media. Chemistry 2016; 22:14890-14901. [PMID: 27573342 DOI: 10.1002/chem.201602079] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Indexed: 11/09/2022]
Abstract
The synthesis of a new ligand (L1) containing two 1,4,7-triazacyclononane ([9]aneN3 ) moieties linked by a 4,5-dimethylenacridine unit is reported. The binding and fluorescence sensing properties toward Cu2+ , Zn2+ , Cd2+ , and Pb2+ of L1 and receptor L2, composed of two [9]aneN3 macrocycles bridged by a 6,6''-dimethylen-2,2':6',2''-terpyridine unit, have been studied by coupling potentiometric, UV/Vis absorption, and emission measurements in aqueous media. Both receptors can selectively detect Zn2+ thanks to fluorescence emission enhancement upon metal binding. The analysis of the binding and sensing properties of the Zn2+ complexes toward inorganic anions revealed that the dinuclear Zn2+ complex of L1 selectively binds and senses the triphosphate anion (TP), whereas the mononuclear Zn2+ complex of L2 displays selective recognition of diphosphate (DP). Binding of TP or DP induces emission quenching of the Zn2+ complexes with L1 and L2, respectively. These results are exploited to discuss the role played by pH, number of coordinated metal cations, and binding ability of the bridging units in metal and/or anion coordination and sensing.
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Effect of the SOD mimetic MnL4 on in vitro and in vivo oxaliplatin toxicity: Possible aid in chemotherapy induced neuropathy. Free Radic Biol Med 2016; 93:67-76. [PMID: 26828020 DOI: 10.1016/j.freeradbiomed.2016.01.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 01/11/2016] [Accepted: 01/27/2016] [Indexed: 01/12/2023]
Abstract
BACKGROUND One of the most discomfortable dose-limiting adverse reactions of effective drugs for the treatment of solid tumors is a peripheral neuropathy which is the main reason for dose reduction and discontinuation of the therapy. We identified oxidative stress as one target of oxaliplatin toxicity in the search of possible adjuvant therapies to prevent neuropathy and alleviate pain. Therefore, we studied an effective SOD mimetic compound, MnL4, as a possible adjuvant treatment in in vitro cellular cultures and in vivo on a rat model of oxaliplatin-induced neuropathy. METHODS AND RESULTS All rat manipulations were carried out according to the European Community guidelines for animal care. We performed experiments on SH-SY5Y, HT-29 and primary cortical rat astrocytes. Incubation with 100 µM oxaliplatin increased superoxide anion production and caspase 3/7 activity in the neuronal cell line SH-SY5Y and cortical astrocytes. MnL4 (10 µM) significantly reduced the increase in superoxide anion in both cell types, but prevented caspase 3/7 activity only in astrocytes. MnL4 reduced lipid peroxidation induced by oxaliplatin and normalized the intracellular calcium signal evoked by ATP and acetylcholine in astrocytes, preincubated with oxaliplatin. MnL4 did not interfere with the concentration- and time-dependent cytotoxic effects of oxaliplatin on the cancer cell lines HT-29 and LoVo. In vivo MnL4 reduced the response at mechanical noxious and mechanical and thermal non-noxious stimuli in oxaliplatin treated animals. Rat rota-rod performances were improved. CONCLUSION Since MnL4 exerts its beneficial effects without interfering with the anticancer activity of oxaliplatin, it could be proposed as adjuvant to prevent and reduce oxaliplatin induced neuropathy.
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Catching anions with coloured assemblies: binding of pH indicators by a giant-size polyammonium macrocycle for anion naked-eye recognition. Org Biomol Chem 2016; 14:8309-21. [DOI: 10.1039/c6ob01474g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Among inorganic anions, only triphosphate displaces bromocresol purple from its assembly with a tetra-cyclam macrocycle, allowing for its selective colorimetric detection.
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Enhanced intra-cutaneous delivery of a Mn-containing antioxidant drug by high-frequency ultrasounds. J Pharm Biomed Anal 2014; 106:197-203. [PMID: 25483173 DOI: 10.1016/j.jpba.2014.11.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 11/07/2014] [Accepted: 11/11/2014] [Indexed: 11/16/2022]
Abstract
This study was carried out to evaluate whether high-frequency ultrasounds, a commonly used aesthetic medicine treatment for skin rejuvenation, may enhance the penetration of the Mn-containing compound Mn(II)(Me2DO2A) (manganese(II) 4,10-dimethyl-1,4,7,10-tetraazacyclododecane-1,7-diacetate) biologically active as a superoxide anion scavenger, in the cutaneous layers of ex vivo human skin explants. Although its antioxidant properties are well known and the compound is basically not toxic in animal models, its trans-cutaneous permeation and its toxicological profile at a systemic level have not yet fully analyzed. Therefore, its possible penetration in the deep cutaneous layers was also evaluated. To this purpose, Mn(II)(Me2DO2A) was formulated as emulsion-gel, lipogel and hydrogel. These different formulations were also tested in combination with high-frequency ultrasounds (10-3500 Hz frequency modulation on a 5 MHz main frequency) used as physical permeation enhancers, delivered by a MedVisage™ device (General Project, Montespertoli, Italy) currently used for aesthetic medicine purposes. The permeation of the Mn-containing compound from the formulations was evaluated by inductively coupled plasma atomic emission spectrometry (ICP-AES) measurements of Mn in horizontal cryosections of the skin samples cut at different depths to separate the epidermis, papillary and reticular dermis, as well as by vertical Franz diffusion cells. The results show that the hydrogel formulation yielded the highest transepidermal delivery of Mn(II)(Me2DO2A) and that the application of ultrasounds (3 W, FM 100 Hz, 2×10 s) significantly enhanced its penetration into the epidermis and upper dermal layers. Of note, nearly undetectable amounts of Mn(II)(Me2DO2A) were detected in the reticular dermis and the Franz cell fluid. Although an in vivo confirmation of these results will be necessary, this method may allow to minimize undesired drug passage to the bloodstream and undesired delivery to non-target internal organs and avoiding its renal excretion and release into the environment.
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A new low molecular weight, MnII-containing scavenger of superoxide anion protects cardiac muscle cells from hypoxia/reoxygenation injury. Free Radic Res 2014; 49:67-77. [PMID: 25348343 DOI: 10.3109/10715762.2014.979168] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Reperfusion injury after oxygen starvation is a key pathogenic step in ischemic diseases. It mainly consists in oxidative stress, related to mitochondrial derangement and enhanced generation of reactive oxygen species (ROS), mainly superoxide anion (O2(•2)), and peroxynitrite by cells exposed to hypoxia. This in vitro study evaluates whether Mn(II)(4,10-dimethyl-1,4,7,10-tetraazacyclododecane-1,7-diacetate).2H2O, or Mn(II)(Me2DO2A), a new low molecular weight, Mn(II)-containing O2(•) scavenger, has a direct protective action on H9c2 rat cardiac muscle cells subjected to hypoxia and reoxygenation. Mn(II)(Me2DO2A) (1 and 10 μmol/l) was added to the culture medium at reoxygenation and maintained for 2 h. In parallel experiments, the inactive congener Zn(II)(Me2DO2A), in which Zn(II) replaced the functional Mn(II) center in the same organic scaffold, was used as negative control. Mn(II)(Me2DO2A) (10 μmol/l) significantly increased cardiac muscle cell viability (trypan blue assay), improved mitochondrial activity (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide test, membrane potential Δψ), reduced apoptosis (mitochondrial permeability transition pore opening, caspase-3, terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling assay), decreased intracellular ROS levels (2',7'-dichlorodihydrofluorescein diacetate and MitoSOX assays), and decreased protein nitroxidation (nitrotyrosine [NT] expression) and DNA oxidation (8-hydroxy-deoxyguanosine levels). Of note, Zn(II)(Me2DO2A) had no protective effect. The mechanism of Mn(II)(Me2DO2A) relies on concentration-dependent removal of harmful O2(•) generated at reoxygenation from dysfunctional mitochondria in hypoxia-induced cells, as indicated by the MitoSOX assay. This study suggests that Mn(II)(Me2DO2A) is a promising antioxidant drug capable of reducing O2(•)-mediated cell oxidative stress which occurs at reoxygenation after hypoxia. In perspective, Mn(II)(Me2DO2A) might be used to reduce ischemia-reperfusion organ damage in acute vascular diseases, as well as to extend the viability of explanted organs before transplantation.
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Zn(II) enhances nucleotide binding and dephosphorylation in the presence of a poly(ethylene imine) dendrimer. Inorganica Chim Acta 2014. [DOI: 10.1016/j.ica.2013.11.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Tuning the Emission Properties of Fluorescent Ligands by Changing pH: The Unusual Case of an Acridine-Containing Polyamine Macrocycle. J Phys Chem A 2013; 117:3798-808. [DOI: 10.1021/jp4015756] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Metal Ion Binding by a G-2 Poly(ethylene imine) Dendrimer. Ion-Directed Self-Assembling of Hierarchical Mono- and Two-Dimensional Nanostructured Materials. Inorg Chem 2013; 52:2125-37. [DOI: 10.1021/ic3025292] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Separation of Copper(II) from Base Metals in an Acidic Synthetic Sulfate Leach Solution Using a Novel 1-Octylimidazole-2-Aldoxime Extractant. SOLVENT EXTRACTION AND ION EXCHANGE 2013. [DOI: 10.1080/07366299.2012.700594] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Glyphosate and ATP binding by mononuclear Zn(II) complexes with non-symmetric ditopic polyamine ligands. Dalton Trans 2012; 41:10521-32. [PMID: 22785253 DOI: 10.1039/c2dt31110k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Binding of Zn(II) by the ditopic ligands L1py, L2py and L1para, composed of a cyclam unit linked to the linear polyamines 1,4,8,11-tetraazaundecane (L1py and L2para) and 1,4,7-triazaheptane (L2py) via a 2,6-dimethylpyridinyl (L1py and L2py) or a 1,4-dimethylbenzyl spacer (L2para), has been analyzed by means of potentiometric and (1)H and (13)C NMR measurements. All ligands form stable mononuclear Zn(II) complexes in a wide pH range, featuring the metal ion bound to the macrocyclic unit. The open-chain polyamine unit can easily bind several protons in aqueous solution affording protonated metal complexes at neutral and acidic pH values. These complexes behave as bifunctional receptors for the anionic substrates N-(phosphonomethyl)glycine (glyphosate or PMG) and ATP. Potentiometric, (1)H and (31)P NMR measurements show that the Zn(II) complex with L1py is the better receptor for both substrates, thanks to the simultaneous presence of a pyridine linker functionalized at its 2,6 positions and of a flexible linear tetraamine chain. In fact, these structural features allow a stronger interaction of PMG and ATP with both the protonated tetraamine moiety and the Zn(II)-cyclam core.
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Thermodynamic and fluorescence emission properties of the Zn(II), Cd(II) and Pb(II) complexes with a fluorescent chelator bearing phenanthroline and naphthalene subunits. Inorganica Chim Acta 2012. [DOI: 10.1016/j.ica.2011.09.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Selective binding and fluorescence sensing of diphosphate in H2OviaZn2+-induced allosteric regulation of the receptor structure. Chem Commun (Camb) 2012; 48:139-41. [DOI: 10.1039/c1cc15934h] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Exploring the Binding Ability of Polyammonium Hosts for Anionic Substrates: Selective Size-Dependent Recognition of Different Phosphate Anions by Bis-macrocyclic Receptors. Inorg Chem 2011; 50:7202-16. [DOI: 10.1021/ic2007815] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Exploring new molecular architectures for anion recognition: synthesis and ATP binding properties of new cyclam-based ditopic polyammonium receptors. Chem Asian J 2011; 6:1582-94. [PMID: 21557488 DOI: 10.1002/asia.201100046] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Indexed: 11/06/2022]
Abstract
Synthesis and characterization of three new polyamine receptors, composed of a cyclam unit (cyclam=1,4,8,11-tetraazacyclotetradecane) linked by a 2,6-dimethylpyridinyl spacer to the linear polyamines 1,4,8,11-tetraazaundecane (L1py), 1,4,7-triazaheptane (L2py), and to a quaternary ammonium group (L3py(+)), are reported. All receptors form highly charged polyammonium cations at neutral pH, suitable for anion recognition studies. ATP recognition was analyzed by using potentiometric, calorimetric, (1)H and (31)P NMR measurements in aqueous solution. All receptors form 1:1 adducts with ATP in aqueous solution, stabilized by charge-charge and hydrogen-bonding interactions between their ammonium groups and the anionic triphosphate chain of ATP. The binding ability of the three receptors for ATP increases in the order of L3py(+)<L2py<L1py. These adducts are stabilized by largely favourable entropic contributions, probably due to the large desolvation of the host and guest species upon complexation. The sequence observed for the binding affinity is explained in terms of the different ability of the three receptors to wrap around the phosphate chain of ATP.
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Molecular recognition of ADP over ATP in aqueous solution by a polyammonium receptor containing a pyrimidine residue. Chem Commun (Camb) 2011; 47:2814-6. [PMID: 21283835 DOI: 10.1039/c0cc05054g] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The synergistic action of the different binding groups of the polyfunctional HL receptor leads to the recognition of ADP over ATP in water, with a selectivity coefficient of up to 116, a phenomenon which is unprecedented in the context of synthetic receptors in water. The recognition is mostly due to the good matching between H(3)L(2+) and the protonated forms of ADP.
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Binding and recognition of AMP, ADP, ATP and related inorganic phosphate anions by a tren-based ligand containing a pyrimidine functionality. NEW J CHEM 2011. [DOI: 10.1039/c1nj20393b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Modeling and Biological Investigations of an Unusual Behavior of Novel Synthesized Acridine-Based Polyamine Ligands in the Binding of Double Helix and G-Quadruplex DNA. ChemMedChem 2010; 5:1995-2005. [DOI: 10.1002/cmdc.201000332] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Low molecular weight compounds with transition metals as free radical scavengers and novel therapeutic agents. Cardiovasc Hematol Agents Med Chem 2010; 8:128-146. [PMID: 20438441 DOI: 10.2174/187152510791698389] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Accepted: 04/13/2010] [Indexed: 05/29/2023]
Abstract
Molecules able to modulate the levels of endogenous free radicals, such as reactive oxygen species (ROS) and nitric oxide (NO), are of pivotal interest for pharmacological and pharmaceutical sciences because of their potential therapeutic relevance. In fact, ROS and NO, which are normal products of cell metabolism, may play a dual beneficial/deleterious role, depending on local concentration and mode of generation. As such, they have been identified as key pathogenic factors for many inflammatory, vascular dysfunctional and degenerative disorders, including atherosclerosis, hypertension, cardiovascular and neurodegenerative diseases, cancer, diabetes mellitus, and ageing. Therefore, the identification and characterization of novel antioxidant/free radical scavenger molecules may expand the current therapeutic implements for the treatment and prevention of the above diseases. In this perspective, low molecular weight complexes of transition metals with organic scaffolds are viewed and investigated as promising pharmaceutical agents. These complexes take advantage of the known principles of inorganic chemistry, i.e. the ability of transition metals, Fe(II), Co(II), Mn(II) and Ru(II), to bind to and react with NO and/or ROS, to counterbalance excessive endogenous free radical generation in biological systems. Among NO scavengers, representative examples are iron complexes with dithiocarbamates or ruthenium compounds with polyamine-polycarboxylate scaffolds; on the other hand, manganese-based molecules appear effective as ROS scavengers. Of note, Mn(II)-containing molecules, currently under study as ROS scavengers, have major functional similarities to Mn-superoxide dismutase (SOD), a Mn-containing enzyme acting as potent endogenous anti-oxidant. In this article, we briefly summarize the state-of-the-art concerning the chemical and biological properties of transition metal ion complexes with low molecular weight synthetic ligands as ROS/NO scavengers provided with therapeutic effectiveness in animal models of free radical-induced diseases. A proper design of the organic scaffolds may yield metal complexes which are stable in aqueous solution in a wide range of physical and chemical conditions, thus preventing release of the metal and the related toxicity. These metal-based compounds may be viewed as a novel class of drugs helpful to reduce vascular dysfunction and oxidative tissue injury due to derangements of the endogenous generation/catabolism of NO and ROS.
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Suppression of allergen-induced respiratory dysfunction and airway inflammation in sensitized guinea pigs by Mn(II)(Me(2)DO2A), a novel superoxide scavenger compound. Free Radic Biol Med 2010; 48:1525-34. [PMID: 20227487 DOI: 10.1016/j.freeradbiomed.2010.02.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Revised: 02/15/2010] [Accepted: 02/26/2010] [Indexed: 11/16/2022]
Abstract
Reactive oxygen species produced during allergic inflammation are key players of the pathophysiology of asthma, leading to oxidative tissue injury and inactivation of endogenous manganese superoxide dismutase (MnSOD). On this ground, removal of excess superoxide anion by scavenger molecules would be beneficial and protective. Here we show that a novel manganese(II)-containing polyamine-polycarboxylic compound, termed Mn(II)(Me(2)DO2A), with potent superoxide dismuting properties decreases the respiratory and histopathological lung abnormalities due to allergen inhalation in a model of ovalbumin (OA)-induced allergic asthma-like reaction in sensitized guinea pigs. Severe respiratory dysfunction in response to OA aerosolic challenge arose rapidly in the sensitized animals and was accompanied by bronchoconstriction, alveolar hyperinflation, mast cell activation, increased leukocyte infiltration (evaluated by myeloperoxidase assay), oxidative lung tissue injury (evaluated by the thiobarbituric-acid-reactive substances and nitrotyrosine immunostaining), decay of endogenous MnSOD activity, production of pro-inflammatory prostaglandins, and lung cell apoptosis. Treatment with Mn(II)(Me(2)DO2A) (15mg/kg, given 1h before allergen challenge), but not the inactive congener Zn(II)(Me(2)DO2A) lacking redox-active metal site, significantly attenuated all the above functional, histopathological and biochemical parameters of allergic inflammation and restored the levels of MnSOD activity. In conclusion, our findings support the potential therapeutic use of Mn(II)(Me(2)DO2A) as novel superoxide scavenger drug in asthma and anaphylactic reactions.
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Binding of H+ and Zn(ii) ions with a new fluorescent macrocyclic phenanthrolinophane. Dalton Trans 2010; 39:10128-36. [DOI: 10.1039/c0dt00534g] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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DNA interaction with Ru(ii) and Ru(ii)/Cu(ii) complexes containing azamacrocycle and dppz residues. A thermodynamic, kinetic and theoretical study. Dalton Trans 2010; 39:9838-50. [DOI: 10.1039/c0dt00552e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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A novel manganese complex effective as superoxide anion scavenger and therapeutic agent against cell and tissue oxidative injury. J Med Chem 2009; 52:7273-83. [PMID: 19860434 DOI: 10.1021/jm901298x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two cyclic polyamine-polycarboxylate ligands, 1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (H(2)L3) and 4,10-dimethyl-1,4,7,10-tetraazacyclododecane-1,7-diacetic acid (H(2)L4), and two noncyclic scaffolds, N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid (H(3)L1) and ethylene-bisglycol-tetracetic acid (H(4)L2), form stable complexes with Mn(II) in aqueous solutions. Cyclic voltammograms show that the complexes with the most hydrophobic ligands, [MnL2](2-) and [MnL4], are oxidized at higher potential than [MnL1](-) and [MnL3]. The pharmacological properties of these molecules were evaluated as superoxide ion scavengers and anti-inflammatory compounds. Among the four complexes, [MnL4] was the most bioactive, being effective in the nanomolar/micromolar range. It abates the levels of key markers of oxidative injury on cultured cells and ameliorates the outcome parameters in animal models of acute and chronic inflammation. [MnL4] toxicity was very low on both cell cultures in vitro and mice in vivo. Hence, we propose [MnL4] as a novel stable oxygen radical scavenging molecule, active at low doses and with a low toxicity.
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Exploring the binding ability of phenanthroline-based polyammonium receptors for anions: hints for design of selective chemosensors for nucleotides. J Org Chem 2009; 74:7349-63. [PMID: 19743804 DOI: 10.1021/jo901423m] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of receptor 2,6,10,14,18-pentaaza[20]-21,34-phenanthrolinophane (L1), containing a pentaamine chain linking the 2,9 positions of a phenanthroline unit, is reported. The protonation features of L1 and of receptor 2,6,10,14,18,22-hexaaza[23]-24,37-phenanthrolinophane (L2) have been studied by means of potentiometric, (1)H NMR, and spectrofluorimetric measurements; this study points out that the fluorescent emission of both receptors depends on the protonation state of the polyamine chain. In fact, the receptors are emissive only at neutral or acidic pH values, where all the aliphatic amine groups are protonated. Potentiometric titrations show that L2 is able to bind selectively ATP over TTP, CTP, and GTP. This selectivity is lost in the case of L1. (1)H and (31)P NMR measurements and molecular mechanics calculations show that the phosphate chains of nucleotides give strong electrostatic and hydrogen-bonding interactions with the ammonium groups of the protonated receptors, while the nucleobases interact either via pi-stacking with phenanthroline or via hydrogen bonding with the ammonium groups. Of note, MM calculations suggest that all nucleotides interact in an inclusive fashion. In fact, in all adducts the phosphate chain is enclosed within the receptor cavities. This structural feature is confirmed by the crystal structure of the [(H(6)L2)(2)(TTP)(2)(H(2)O)(2)](4+) adduct. Fluorescence emission measurements at different pH values show that L2 is also able to ratiometrically sense ATP in a narrow pH range, thanks to emission quenching due to a photoinduced electron transfer (PET) process from an amine group of the receptor to the excited phenanthroline.
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Novel fluorimetric bulk optode membrane based on 5,8-bis((5'-chloro-8'-hydroxy-7'-quinolinyl)methyl)-2,11-dithia-5,8-diaza-2,6-pyridinophane for selective detection of lead(II) ions. Talanta 2009; 80:2023-33. [PMID: 20152448 DOI: 10.1016/j.talanta.2009.11.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 10/31/2009] [Accepted: 11/02/2009] [Indexed: 10/20/2022]
Abstract
A novel fluorescence chemical sensor for the highly sensitive and selective determination of Pb(2+) ions in aqueous solutions is described. The preliminary potentiometric and spectrofluorimetric complexation studies in solution revealed that the lipophilic ligand 5,8-bis((5'-chloro-8'-hydroxy-7'-quinolinyl)methyl)-2,11-dithia-5,8-diaza-2,6-pyridinophane (L2) forms a highly stable and selective [PbL2](2+) and [Pb(L2)(2)](2+) complexes which results in a strong fluorescence quenching of the ligand. Thus, a novel fluorescence Pb(2+) sensing system was prepared by incorporating L2 as a neutral lead-selective fluoroionophore in the plasticized PVC membrane containing tetrakis(p-chlorophenyl) borate as a liphophilic anionic additive. The response of the sensor is based on the strong selective fluorescence quenching of L2 by Pb(2+) ions. At pH 5.5, the proposed sensor displays a calibration curve over a wide concentration range of 3.0 x 10(-7) to 2.5x 10(-2)M with a relatively fast response time of less than 5 min. In addition to high stability, reversibility and reproducibility, the sensor shows a unique selectivity towards Pb(2+) ion with respect to common coexisting cations. The proposed fluorescence optode was successfully applied to the determination of lead in plastic toys and tap water samples.
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A Tris-Macrocycle with Proton Sponge Characteristics as Efficient Receptor for Inorganic Phosphate and Nucleotide Anions. European J Org Chem 2009. [DOI: 10.1002/ejoc.200900770] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Synthesis and Coordination Properties of Quinoline Pendant Arm Derivatives of [9]aneN3 and [9]aneN2S as Fluorescent Zinc Sensors. Inorg Chem 2009; 48:9236-49. [DOI: 10.1021/ic901012w] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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