Mn(II) complexes with sulfonamides as ligands.

Macı́as, Benigno; Villa, M.; Lapresa, Rebeca; Alzuet, Gloria; Hernández-Gil, Javier; Sanz, Francisca

doi:10.1016/j.jinorgbio.2012.05.019

Cited by 17 publications

(7 citation statements)

References 47 publications

(50 reference statements)

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“… 44 − 49 The distances to carboxylate oxygen atoms fall also within the expected range. 49 , 50 The sulfonamide group coordinates through the nitrogen atom, 51 , 52 and the Mn–N4 distance is ∼0.04 Å longer than those involving carboxylate oxygen atoms.…”

Section: Resultsmentioning

confidence: 99%

Understanding the Effect of the Electron Spin Relaxation on the Relaxivities of Mn(II) Complexes with Triazacyclononane Derivatives

et al. 2021

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Investigating the relaxation of water 1 H nuclei induced by paramagnetic Mn(II) complexes is important to understand the mechanisms that control the efficiency of contrast agents used in diagnostic magnetic resonance imaging (MRI). Herein, a series of potentially hexadentate triazacyclononane (TACN) derivatives containing different pendant arms were designed to explore the relaxation of the electron spin in the corresponding Mn(II) complexes by using a combination of 1 H NMR relaxometry and theoretical calculations. These ligands include 1,4,7-triazacyclononane-1,4,7-triacetic acid (H 3 NOTA) and three derivatives in which an acetate group is replaced by sulfonamide (H 3 NO2ASAm), amide (H 2 NO2AM), or pyridyl (H 2 NO2APy) pendants. The analogue of H 3 NOTA containing three propionate pendant arms (H 3 NOTPrA) was also investigated. The X-ray structure of the derivative containing two acetate groups and a sulfonamide pendant arm [Mn(NO2ASAm)] − evidenced six-coordination of the ligand to the metal ion, with the coordination polyhedron being close to a trigonal prism. The relaxivities of all complexes at 20 MHz and 25 °C (1.1–1.3 mM –1 s –1 ) are typical of systems that lack water molecules coordinated to the metal ion. The nuclear magnetic relaxation profiles evidence significant differences in the relaxivities of the complexes at low fields (<1 MHz), which are associated with different spin relaxation rates. The zero field splitting (ZFS) parameters calculated by using DFT and CASSCF methods show that electronic relaxation is relatively insensitive to the nature of the donor atoms. However, the twist angle of the two tripodal faces that delineate the coordination polyhedron, defined by the N atoms of the TACN unit (lower face) and the donor atoms of the pendant arms (upper face), has an important effect in the ZFS parameters. A twist angle close to the ideal value for an octahedral coordination (60°), such as that in [Mn(NOTPrA)] − , leads to a small ZFS energy, whereas this value increases as the coordination polyhedron approaches to a trigonal prism.

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Section: Resultsmentioning

confidence: 99%

Understanding the Effect of the Electron Spin Relaxation on the Relaxivities of Mn(II) Complexes with Triazacyclononane Derivatives

et al. 2021

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“…Studies aimed at the design of conformation‐ and site‐specified reagents supply rationale for novel drug styling as well as improved susceptible chemical probes for the structure of nucleic acids. Recently, the interactions between nucleic acids and transition metal complexes have attracted great attention, because of their importance in the evolution of unprecedented reagents for medical science and biotechnology …”

Section: Introductionmentioning

confidence: 99%

Synthesis, structural characterization and DNA binding affinity of new bioactive nano‐sized transition metal complexes with sulfathiazole azo dye for therapeutic applications

Saad

El‐Ghamry

Kassem

2019

Applied Organom Chemis

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The azo dye ligand 4‐(5‐chloro‐2‐hydroxyphenylazo)‐N‐thiazol‐2‐ylbenzenesulfonamide (H2L) formed by the coupling reaction of sulfathiazole and p‐chlorophenol was synthesized and characterized using elemental analysis and Fourier transform infrared (FT‐IR) as well as UV–visible spectra. Nano‐sized divalent Cu, Co, Ni, Mn and Zn complexes of the synthesized azo dye ligand were prepared and investigated using various spectroscopic and analytical techniques. Elemental and thermal analyses indicated the formation of the Cu(II), Ni(II) and Mn(II) complexes in a molar ratio of 1:2 (L:M) while Co(II) and Zn(II) complexes exhibited a 1:1 (M:L) ratio. FT‐IR spectral studies confirmed the coordination of the ligand to the metal ions through the phenolic hydroxyl oxygen, azo nitrogen, sulfonamide oxygen and/or thiazole nitrogen. The geometric arrangements around the central metal ions were investigated applying UV–visible and electron spin resonance spectra, thermogravimetric analysis and molar conductance measurements. X‐ray diffraction patterns revealed crystalline nature of H2L and amorphous nature of all synthesized complexes. Transmission electron microscopy images confirmed nano‐sized particles and their homogeneous distribution over the complex surface. Antibacterial, antifungal and antitumour activities of the investigated complexes were screened compared with familiar standard drugs to confirm their potential therapeutic applications. The Cu(II) complex showed IC50 of 3.47 μg ml−1 (5.53 μM) against hepatocellular carcinoma cells, which means that it is a more potent anticancer drug compared with the standard cisplatin (IC50 = 3.67 μg ml−1 (12.23 μM)). Furthermore, the Co(II), Ni(II), Cu(II) and Zn(II) complexes displayed IC50 greater than that of an applied standard anticancer agent (5‐flurouracil) towards breast carcinoma cells. Hence, these complexes can be considered as promising anticancer drugs. The mode of binding of the complexes with salmon serum DNA was determined through electronic absorption titration and viscosity studies.

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“…Viscosity measurements are regarded as the most unambiguous and decisive test for providing reliable evidence of the DNA binding mode . When small molecules bind to DNA through classical intercalation, they will cause the DNA helix to lengthen and an increase in DNA viscosity as the base pairs are separated to accommodate the binding ligand, while a partial or non‐classical intercalation ligand can bend (or kink) the DNA helix, typically reducing its effective length and concomitantly its viscosity .…”

Section: Resultsmentioning

confidence: 99%

Deciphering the intercalative binding modes of benzoyl peroxide with calf thymus DNA

2017

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The binding of benzoyl peroxide (BPO), a flour brightener, with calf thymus DNA (ctDNA) was predicted by molecular simulation, and this were confirmed using multi-spectroscopic techniques and a chemometrics algorithm. The molecular docking result showed that BPO could insert into the base pairs of ctDNA, and the adenine bases were the preferential binding sites which were validated by the analysis of Fourier transform infrared spectra. The mode of binding of BPO with ctDNA was an intercalation as supported by the results from ctDNA melting and viscosity measurements, iodide quenching effects and competitive binding investigations. The circular dichroism and DNA cleavage assays indicated that BPO induced a conformational change from B-like DNA structure towards to A-like form, but did not lead to significant damage in the DNA. The complexation was driven mainly by hydrogen bonds and hydrophobic interactions. Moreover, the ultraviolet-visible (UV-vis) spectroscopic data matrix was resolved by a multivariate curve resolution-alternating least-squares algorithm. The equilibrium concentration profiles for the components (BPO, ctDNA and BPO-ctDNA complex) were extracted from the highly overlapping composite response to quantitatively monitor the BPO-ctDNA interaction. This study has provided insights into the mechanism of the interaction of BPO with ctDNA and potential hazards of the food additive.

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Mn(II) complexes with sulfonamides as ligands.

Cited by 17 publications

References 47 publications

Understanding the Effect of the Electron Spin Relaxation on the Relaxivities of Mn(II) Complexes with Triazacyclononane Derivatives

Understanding the Effect of the Electron Spin Relaxation on the Relaxivities of Mn(II) Complexes with Triazacyclononane Derivatives

Synthesis, structural characterization and DNA binding affinity of new bioactive nano‐sized transition metal complexes with sulfathiazole azo dye for therapeutic applications

Deciphering the intercalative binding modes of benzoyl peroxide with calf thymus DNA

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