Azido- and chlorido-cobalt complex as carrier-prototypes for antitumoral prodrugs

Pires, Bianca M.; Giacomin, Letícia Carlos; Castro, Frederico Augusto Vieira de; Cavalcanti, Amanda dos Santos; Pereira, Marcos D.; Bortoluzzi, Adaílton J.; Faria, Roberto B.; Scarpellini, Marciela

doi:10.1016/j.jinorgbio.2016.01.024

Cited by 26 publications

(13 citation statements)

References 28 publications

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“…Irreversible cathodic processes are observed at E = À1.65 and À2.05 V Fc+/Fc , assigned to the Ni + /Ni 0 couple and a ligand-centred reduction, respectively. An anodic process at E = +0.9 V Fc+/Fc is attributed to an irreversible ligand oxidation (Pires et al, 2016). This process was also observed in the voltammogram of ligand L, but at a slightly lower potential (E = +0.7 V Fc+/Fc ), along with another irreversible process at E = +1.1 V Fc+/Fc .…”

Section: Electronic and Redox Propertiessupporting

confidence: 56%

“…In the last two decades, our group and others have exploited mononuclear first-row transition-metal complexes containing two labile cis ligands as biomimetic or bio-inspired homogeneous catalysts for a great variety of reactions, such as the oxidation of catechol and cyclohexane (Ferre et al, 2017), the hydrolysis of proteins (Oliveira et al, 2009), phosphodiesters (Scarpellini et al, 2003;Kettenmann et al, 2018) and polysaccharides (Concia et al, 2017), and, more recently, water splitting (Luo et al, 2016). They have also been studied as prodrugs and carrier prototypes for the selective delivery of bioactive substances (Pires et al, 2016;de Souza et al, 2016). The cis arrangement of the labile ligands is usually a requirement for catalytic/biological activity, since it provides a scaffold for substrate coordination and facilitates electron/ atom transfer between the species involved (Lindhorst et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

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An unusual partial occupancy of labile chloride and aqua ligands in cocrystallized isomers of a nickel(II) complex bearing a tripodal N ₄-donor ligand

2020

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A novel Ni2+ complex with the N 4-donor tripodal ligand bis[(1-methyl-1H-imidazol-2-yl)methyl][2-(pyridin-2-yl)ethyl]amine (L), namely, aqua{bis[(1-methyl-1H-imidazol-2-yl-κN 3)methyl][2-(pyridin-2-yl-κN)ethyl]amine-κN}chloridonickel(II) perchlorate, [NiCl(C17H22N6)(H2O)]ClO4 or [NiCl(H2O)(L)Cl]ClO4 (1), was synthesized and characterized by spectroscopic and spectrometric methods. The crystal structure of 1 reveals an interesting and unusual cocrystallization of isomeric complexes, which are crystallographically disordered with partial occupancy of the labile cis aqua and chloride ligands. The Ni2+ centre exhibits a distorted octahedral environment, with similar bond lengths for the two Ni—N(imidazole) bonds. The bond length increases for Ni—N(pyridine) and Ni—N(amine), which is in agreement with literature examples. The bond lengths of the disordered labile sites are also in the expected range and the Ni—Cl and Ni—O bond lengths are comparable with similar compounds. The electronic, redox and solution stability behaviour of 1 were also evaluated, and the data obtained suggest the maintenance of structural integrity, with no sign of demetalation or decomposition under the studied conditions.

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Section: Electronic and Redox Propertiessupporting

confidence: 56%

Section: Introductionmentioning

confidence: 99%

An unusual partial occupancy of labile chloride and aqua ligands in cocrystallized isomers of a nickel(II) complex bearing a tripodal N ₄-donor ligand

2020

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“…Zhao et al also combined the photoresponsive ROS generator W18O49 and TPZ to achieve a synergistic anticancer outcome. Besides TPZ, some other bioreductive prodrugs, such as cobalt(III) complexes and 3-(2-nitrophenyl) propionic acid-paclitaxel (NPPA-PTX), can experience similar transformation under hypoxic conditions to achieve light-assisted anticancer efficacy. , Under hypoxia, 3d 6 cobalt(III) complexes can be reduced to 3d 7 cobalt(II) to release the active drug, whereas NPPA-PTX can be reduced gradually into hydroxy-amine or amino derivatives to release PTX.…”

Section: Indirect Photoresponsive Delivery Systemsmentioning

confidence: 99%

Photoresponsive Drug/Gene Delivery Systems

et al. 2018

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Light as an external stimulus can be precisely manipulated in terms of irradiation time, site, wavelength, and density. As such, photoresponsive drug/gene delivery systems have been increasingly pursued and utilized for the spatiotemporal control of drug/gene delivery to enhance their therapeutic efficacy and safety. In this review, we summarized the recent research progress on photoresponsive drug/gene delivery, and two major categories of delivery systems were discussed. The first category is the direct responsive systems that experience photoreactions on the vehicle or drug themselves, and different materials as well as chemical structures responsive to UV, visible, and NIR light are summarized. The second category is the indirect responsive systems that require a light-generated mediator signal, such as heat, ROS, hypoxia, and gas molecules, to cascadingly trigger the structural transformation. The future outlook and challenges are also discussed at the end.

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“…The modulation of reactivity promoted by metals has also been explored in the design of donors of either nitric oxide or CO, where ruthenium-based compounds have stood out (Tfouni et al, 2012 ; Wright and Wright, 2016 ). Light and electron-transfer triggered processes have been used to generate cytotoxic metal-based compounds with production of reactive oxygen species (ROS), release of NO or CO, and hypoxia-responsive agents (Tfouni et al, 2010 ; Li et al, 2015 ; Pires et al, 2016 ; Romo et al, 2016 ; Sousa et al, 2016 ; Abreu et al, 2017 ; de Sousa et al, 2017 ). Cobalt(III) complexes, for example, have been used to release drugs or agents for imaging under hypoxia conditions, which enables reduction of Co(III) to Co(II).…”

Section: Developing New Pharmacological Strategies Using Metalsmentioning

confidence: 99%

“…Cobalt(III) complexes, for example, have been used to release drugs or agents for imaging under hypoxia conditions, which enables reduction of Co(III) to Co(II). The latter redox state is labile promoting the release of the active ligand that might be used to target tumors (Graf and Lippard, 2012 ; Pires et al, 2016 ). Catalytic-based metallodrugs have also been described, including intracellular reduction of copper(II) complexes that can generate ROS cytotoxic species (Romo et al, 2016 ; Yu and Cowan, 2017 ).…”

Section: Developing New Pharmacological Strategies Using Metalsmentioning

confidence: 99%

Is IQG-607 a Potential Metallodrug or Metallopro-Drug With a Defined Molecular Target in Mycobacterium tuberculosis?

et al. 2018

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The emergence of strains of Mycobacterium tuberculosis resistant to isoniazid (INH) has underscored the need for the development of new anti-tuberculosis agents. INH is activated by the mycobacterial katG-encoded catalase-peroxidase, forming an acylpyridine fragment that is covalently attached to the C4 of NADH. This isonicotinyl-NAD adduct inhibits the activity of 2-trans-enoyl-ACP(CoA) reductase (InhA), which plays a role in mycolic acid biosynthesis. A metal-based INH analog, Na3[FeII(CN)5(INH)]·4H2O, IQG-607, was designed to have an electronic redistribution on INH moiety that would lead to an intramolecular electron transfer to bypass KatG activation. HPLC and EPR studies showed that the INH moiety can be oxidized by superoxide or peroxide yielding similar metabolites and isonicotinoyl radical only when associated to IQG-607, thereby supporting redox-mediated drug activation as a possible mechanism of action. However, IQG-607 was shown to inhibit the in vitro activity of both wild-type and INH-resistant mutant InhA enzymes in the absence of KatG activation. IQG-607 given by the oral route to M. tuberculosis-infected mice reduced lung lesions. Experiments using early and late controls of infection revealed a bactericidal activity for IQG-607. HPLC and voltammetric methods were developed to quantify IQG-607. Pharmacokinetic studies showed short half-life, high clearance, moderate volume of distribution, and low oral bioavailability, which was not altered by feeding. Safety and toxic effects of IQG-607 after acute and 90-day repeated oral administrations in both rats and minipigs showed occurrence of mild to moderate toxic events. Eight multidrug-resistant strains (MDR-TB) were resistant to IQG-607, suggesting an association between katG mutation and increasing MIC values. Whole genome sequencing of three spontaneous IQG-607-resistant strains harbored katG gene mutations. MIC measurements and macrophage infection experiments with a laboratorial strain showed that katG mutation is sufficient to confer resistance to IQG-607 and that the macrophage intracellular environment cannot trigger the self-activation mechanism. Reduced activity of IQG-607 against an M. tuberculosis strain overexpressing S94A InhA mutant protein suggested both the need for KatG activation and InhA as its target. Further efforts are suggested to be pursued toward attempting to translate IQG-607 into a chemotherapeutic agent to treat tuberculosis.

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Azido- and chlorido-cobalt complex as carrier-prototypes for antitumoral prodrugs

Cited by 26 publications

References 28 publications

An unusual partial occupancy of labile chloride and aqua ligands in cocrystallized isomers of a nickel(II) complex bearing a tripodal N ₄-donor ligand

An unusual partial occupancy of labile chloride and aqua ligands in cocrystallized isomers of a nickel(II) complex bearing a tripodal N ₄-donor ligand

Photoresponsive Drug/Gene Delivery Systems

Is IQG-607 a Potential Metallodrug or Metallopro-Drug With a Defined Molecular Target in Mycobacterium tuberculosis?

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Azido- and chlorido-cobalt complex as carrier-prototypes for antitumoral prodrugs

Cited by 26 publications

References 28 publications

An unusual partial occupancy of labile chloride and aqua ligands in cocrystallized isomers of a nickel(II) complex bearing a tripodal N 4-donor ligand

An unusual partial occupancy of labile chloride and aqua ligands in cocrystallized isomers of a nickel(II) complex bearing a tripodal N 4-donor ligand

Photoresponsive Drug/Gene Delivery Systems

Is IQG-607 a Potential Metallodrug or Metallopro-Drug With a Defined Molecular Target in Mycobacterium tuberculosis?

Contact Info

Product

Resources

About

An unusual partial occupancy of labile chloride and aqua ligands in cocrystallized isomers of a nickel(II) complex bearing a tripodal N ₄-donor ligand

An unusual partial occupancy of labile chloride and aqua ligands in cocrystallized isomers of a nickel(II) complex bearing a tripodal N ₄-donor ligand