Synthesis and photophysical characterization of novel Ir(III) complexes with a dipyridophenazine analogue (ppdh) as ancillary ligand

González, Iván; Gómez, Josselyn; Santander-Nelli, Mireya; Natali, Mirco; Cortés‐Arriagada, Diego; Dreyse, Paulina

doi:10.1016/j.poly.2020.114621

Cited by 9 publications

(8 citation statements)

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“…In this work, we tested a coordination compound characterized by a positive charge in the first coordination sphere (Figure 4B). The photophysical evaluation of the PSIR-3 performed in acetonitrile solution [40] revealed absorption processes at 375 and 392 nm attributable at the first instance of charge-transfer transitions (Figure 4C,D) [32]. When the We have previously shown that Ir(III)-based compounds, such as PSIR-3, have photodynamic antimicrobial activity against imipenem-resistant Klebsiella pneumoniae [32,33].…”

Section: Photophysical Properties Of the Psir-3 Compoundmentioning

confidence: 88%

“…Pharmaceutics 2021, 13, x FOR PEER REVIEW 12 of 18 PSIR-3 compound was excited with a wavelength corresponding to the lowest chargetransfer absorption energy, 375 nm, it showed maximum emission at 598 nm (Figure 4C,D). Figure 4C shows the recorded lifetimes of excited states in 0.32 µs and the calculated quantum yield (Φem) in 0.011 [40]. The aPDI activity of the PSIR-3 compound was compared with the positive PS control [Ru(bpy)3](PF6)2 (bpy = 2,2′-bipyridine) called PS-Ru.…”

Section: Photophysical Properties Of the Psir-3 Compoundmentioning

confidence: 99%

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Effective Photodynamic Therapy with Ir(III) for Virulent Clinical Isolates of Extended-Spectrum Beta-Lactamase Klebsiella pneumoniae

et al. 2021

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Background: The extended-spectrum beta-lactamase (ESBL) Klebsiella pneumoniae is one of the leading causes of health-associated infections (HAIs), whose antibiotic treatments have been severely reduced. Moreover, HAI bacteria may harbor pathogenic factors such as siderophores, enzymes, or capsules, which increase the virulence of these strains. Thus, new therapies, such as antimicrobial photodynamic inactivation (aPDI), are needed. Method: A collection of 118 clinical isolates of K. pneumoniae was characterized by susceptibility and virulence through the determination of the minimum inhibitory concentration (MIC) of amikacin (Amk), cefotaxime (Cfx), ceftazidime (Cfz), imipenem (Imp), meropenem (Mer), and piperacillin–tazobactam (Pip–Taz); and, by PCR, the frequency of the virulence genes K2, magA, rmpA, entB, ybtS, and allS. Susceptibility to innate immunity, such as human serum, macrophages, and polymorphonuclear cells, was tested. All the strains were tested for sensitivity to the photosensitizer PSIR-3 (4 µg/mL) in a 17 µW/cm2 for 30 min aPDI. Results: A significantly higher frequency of virulence genes in ESBL than non-ESBL bacteria was observed. The isolates of the genotype K2+, ybtS+, and allS+ display enhanced virulence, since they showed higher resistance to human serum, as well as to phagocytosis. All strains are susceptible to the aPDI with PSIR-3 decreasing viability in 3log10. The combined treatment with Cfx improved the aPDI to 6log10 for the ESBL strains. The combined treatment is synergistic, as it showed a fractional inhibitory concentration (FIC) index value of 0.15. Conclusions: The aPDI effectively inhibits clinical isolates of K. pneumoniae, including the riskier strains of ESBL-producing bacteria and the K2+, ybtS+, and allS+ genotype. The aPDI with PSIR-3 is synergistic with Cfx.

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Section: Photophysical Properties Of the Psir-3 Compoundmentioning

confidence: 88%

Section: Photophysical Properties Of the Psir-3 Compoundmentioning

confidence: 99%

Effective Photodynamic Therapy with Ir(III) for Virulent Clinical Isolates of Extended-Spectrum Beta-Lactamase Klebsiella pneumoniae

et al. 2021

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“…In this work, we tested a coordination compound characterized by a positive charge in the first coordination sphere (Figures 4B). The photophysical evaluation of the PSIR-3 performed in acetonitrile solution [40], revealed absorption processes at 375 and 392 nm attributable at the first instance to charge-transfer transitions (Figure 4C and D) [32]. When the PSIR-3 compound was excited with a wavelength corresponding to the lowest charge-transfer absorption energy, 375 nm, it showed maximum emission at 598 nm (Figure 4C and D).…”

Section: Correlation Of Virulence Factors With Antibiotic Resistancementioning

confidence: 99%

“…The structural and photophysical characterization of the PSIR-3 compound was described previously [40]. The complex synthesized can be described using the following general formula: [Ir(C^N)2(N^N)](PF6), where N^N is the ancillary ligand; and C^N corresponds to a cyclometalating ligand.…”

Section: Synthesis Of the Psir-3 Compoundmentioning

confidence: 99%

“…When the PSIR-3 compound was excited with a wavelength corresponding to the lowest charge-transfer absorption energy, 375 nm, it showed maximum emission at 598 nm (Figure 4C and D). Figure 4C shows the recorded lifetimes of excited states in 0.32 s and the calculated quantum yield (em) in 0.011 [40]. The aPDI activity of the PSIR-3 compound was compared with the positive PS control [Ru(bpy)3](PF6)2 (bpy = 2,2´-bipyridine) called PS-Ru.…”

Section: Correlation Of Virulence Factors With Antibiotic Resistancementioning

confidence: 99%

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Effective Photodynamic Therapy with Ir(III) for Virulent Clinical Isolates of Extended-Spectrum Beta-lactamase <em>Klebsiella pneumoniae</em>

Núñez

Palavecino

González

et al. 2021

Preprint

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Background: The extended-spectrum beta-lactamase (ESBL) Klebsiella pneumoniae is one of the leading causes of health-associated infections (HAI), whose antibiotic treatments have been severely reduced. Besides, HAI bacteria may harbor pathogenic factors such as siderophores, enzymes, or capsules, which increase the virulence of these strains. Thus, new therapies such as antimicrobial photodynamic inactivation (aPDI) are needed. Method: A collection of 118 clinical isolates of K. pneumoniae were characterized susceptibility and virulence through the determination of the minimum inhibitory concentration (MIC) of Amk, Cfx, Cfz, Imp, Mer, and Pip-taz, and by PCR, the frequency of the virulence genes, K2, magA, rmpA, entB, ybtS, and allS. Susceptibility to innate immunity, such as human serum, macrophages, and polymorphonuclear cells, was tested. All the strains were tested for sensitivity to the photosensitizer PSIR-3 (4µg/mL) in a 17µW/cm2 for 30 min aPDI. Results: A significantly higher frequency of virulence genes in ESBL than non-ESBL bacteria were observed. The isolates of the genotype K2+, ybtS+, and allS+ display enhanced virulence since they showed higher resistance to human serum as well as to phagocytosis. All strains are susceptible to the aPDI with PSIR-3 decreasing viability in 3log10. The combined treatment with Cfx improved the aPDI to 6log10 for the ESBL strains. The combined treatment is synergistic as it showed an FIC index value of 0.15. Conclusions: The aPDT effectively inhibits clinical isolates of K. pneumoniae, including the more risky strains of ESBL-producing bacteria and the K2+, ybtS+, and allS+ genotype. The aPDI with PSIR-3 is synergistic with Cfx.

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Burning Rate Performance Study of Ammonium Perchlorate Catalyzed by Heteroleptic Copper(I) Complexes with Pyrazino[2,3‐f][1,10]phenanthroline‐Based Ligands

Escobar

Morales-Verdejo

Arroyo³

et al. 2021

Eur J Inorg Chem

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This contribution describes the catalytic effect of heteroleptic Cu(I) complexes with pyrazino[2,3‐f][1,10]phenanthroline‐based ligands (C1‐7) on the thermal decomposition of ammonium perchlorate (AP). The complexes C2 and C4‐7 were synthesized and characterized by NMR, HRMS and, in the case of C7, by X‐ray diffraction. The burning rate performance of C1‐7 on thermal decomposition of AP was studied by differential scanning calorimetry technique. The effect of the counter ion type, the number of metal centers and ligand substitution was evaluated. These AP+complex mixtures exerted a shift to lower ignition temperatures and an increase in the released heats during thermal decomposition compared with pure AP. The compound C4 showed the higher catalytic effect among the complexes series, and C5 exerted the highest energy release, in contrast to the other evaluated complexes and to the reported compounds CuO, [Cu2(en)2(HBTI)2]2 and Catocene.

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Synthesis and photophysical characterization of novel Ir(III) complexes with a dipyridophenazine analogue (ppdh) as ancillary ligand

Cited by 9 publications

References 77 publications

Effective Photodynamic Therapy with Ir(III) for Virulent Clinical Isolates of Extended-Spectrum Beta-Lactamase Klebsiella pneumoniae

Effective Photodynamic Therapy with Ir(III) for Virulent Clinical Isolates of Extended-Spectrum Beta-Lactamase Klebsiella pneumoniae

Effective Photodynamic Therapy with Ir(III) for Virulent Clinical Isolates of Extended-Spectrum Beta-lactamase <em>Klebsiella pneumoniae</em>

Burning Rate Performance Study of Ammonium Perchlorate Catalyzed by Heteroleptic Copper(I) Complexes with Pyrazino[2,3‐f][1,10]phenanthroline‐Based Ligands

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