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Our previous study showed that dithiophenolate (DTP) and its chitosan nanoparticles (DTP-CSNPs) have abilities to bind with DNA helixes. So in this study, their lethal doses (LD50) and therapeutic roles against rat liver injuries induced by carbon tetrachloride (CCl4) were evaluated. The study focused on the determination of the markers of oxidative stress (OS) and apoptosis and compare the results with those of cisplatin treatment. The results revealed that LD50 values of DTP and DTP-CSNPs are 2187.5 and 1462.5 mg/kg, respectively. Treatment with DPT and DPT-CSNPs after CCl4 administration reduced liver injuries, induced by CCl4, and improved liver functions and architecture through the reduction of OS and apoptosis. Where the oxidant marker was decreased with elevations of antioxidant markers. Also, there was an elevation in Bcl-2 value, with decreases in caspase-8, Bax, and Bax/Bcl-2 ratio. DPT-CSNPs treatment gave preferable results than those treated with DPT. Moreover, DTP and DPT-CSNPs treatment gave better results than cisplatin treatment. The administration of healthy rats with low doses of DTP and DTP-CSNPs for 14 days had no effect. Otherwise, the study on HepG2 cell line showed that DTP and DPT-CSNPs inhibited cell growth by arresting cells in the G2/M phase and inducing cell death. In conclusion, DTP and DTP-CSNPs have antiapoptotic and anti-oxidative stress toward hepatotoxicity induced by CCl4. Moreover, DTP and DTP-CSNPs have anticancer activity against the HepG2 cell line. Generally, DTP-CSNPs are more effective than DTP. So, they can be used in the pharmacological fields, especially DTP-CSNPs. [ABSTRACT FROM AUTHOR]

Synthesis and characterization of the ternary copper(II) complexes containing metformin-based mixed ligand system (LL′) in which L is metformin and L′ is glycine or iminodiacetic acid (IDAH2) is the initial goal of the present study. Analytical investigations, mass spectra, electrochemical, thermal, magnetic and spectroscopic measurements assigned the suggested molecular formulae of the current copper(II) chelates. Magnetic and spectral studies suggested square-pyramidal stereochemistry for the three complexes. Furthermore, X-ray structural analysis results demonstrated the square-pyramidal geometry around copper(II) center of complexes 1, 2 and 3. Catechol oxidase and phenoxazinone synthase mimetic activity examinations displayed that the current copper(II) oxidase models efficiently catalyze the oxidative coupling of o-aminophenol (o-APH3) to the corresponding oxidation product aminophenoxazin-3-one core (APX). As well, the current metformin copper(II)-based chelates showed excellent catalytic performance toward the air conversion of the model substrate 3,5-di-tertbutylcatechol (3,5-DTBCH2) to the biologically significant 3,5-di-tertbutylquinone. The catalytic reaction rate dependence on the substrate concentration is consistent with two orders profiles: first order at low substrate concentration and saturation kinetic at the high concentration of substrate. The catalytic efficiency was described by the ratio kcat/KM which follows the order 2 > 1 > 3, and the same order holds for the geometry irregularity of the studied copper(II) complexes. Electrochemical data were employed to describe parameters that determine the rate of intramolecular reactions including the driving force of the reaction (i.e., the free energy change, − ΔGº), the reorganization energy, λ of the reacting redox centers during the aerobic catalytic oxidation of the studied substrates. Based on the kinetic measurements by using stopped-follow spectrophotometer, the probable mechanistic implications of the studied catalytic reactions are discussed. [ABSTRACT FROM AUTHOR]

Electronic interactions between the cationic N,N′-bis(2(trimethylammonium iodide) ethylene)perylene-3,4,9,10-tetracarboxyldiimide (TAIPDI) with two electron donors, namely, pyrene (Py) and 1-pyrenesulfonic acid sodium salt (PySA), have been investigated. The spectroscopic studies showed the formation of the supramolecular conjugate between TAIPDI and PySA via ionic interaction, but not with Py. Density functional theory (DFT) combined with a natural energy decomposition analysis (NEDA) technique showed an S-like structure of the supramolecular conjugate TAIPDI–PySA via an ionic interaction. The formation constant of the TAIPDI–PySA supramolecular conjugate was determined to be 3.0 × 104 M−1, suggesting a fairly stable complex formation. The excited state events were monitored by both steady state and time-resolved emission techniques. Upon excitation, the quenching pathways via the singlet-excited states of TAIPDI and PySA involved the intramolecular electron transfer from the electron donating PySA to the electron accepting TAIPDI with a rate constant of 1.10 × 1011 s−1 and a quantum yield of 0.99. The thermodynamic parameters of the supramolecular TAIPDI–PySA conjugate have been determined using the stopped-flow technique. [ABSTRACT FROM AUTHOR]

A perylene derivative, namely N,N′-bis(2(trimethylammonium iodide)ethylene)perylene-3,4,9,10-tetracarboxyldiimide (TAIPDI) forms nanoscale columnar stacks in water that have been characterized by using optical absorption and emission measurements, dynamic light scattering (DLS), and transmission electron microscopy (TEM). This behaviour was compared with that of unstacked TAIPDI in methanol. Assembly formation between the one-dimensional TAIPDI stacks and zinc phthalocyanine tetrasulphonic groups (ZnPcS4) via strong π–π and ionic interactions has been described in an aqueous medium. The formation constant of the supramolecular dyad has been determined as 2.94 × 104 M−1 from both the absorption and fluorescence measurements. Upon addition of ZnPcS4, the fluorescence quenching of the singlet-excited state of TAIPDI was observed because of the electron transfer process from ZnPcS4 to TAIPDI via the singlet-excited states of ZnPcS4 and TAIPDI entities. The electrochemical studies supported the electron transfer pathways via the singlet states of ZnPcS4 and TAIPDI. The thermodynamic parameters of the supramolecular complex have been determined from stopped-flow measurements. The interaction between ZnPcS4 and TAIPDI occurs in two steps, where the rate constant of the second step with TAIPDI (207 ± 8 M−1 s−1) is much slower than the first one (3515 ± 101 M−1 s−1). Activation parameters for the complex formation (ΔH# = 76 ± 11 kJ mol−1 and ΔS# = 83 ± 37 J K−1 mol−1, and ΔH# = 221 ± 15 kJ mol−1 and ΔS# = 540 ± 50 J K−1 mol−1) were determined from variable temperature studies for the first and second steps, respectively. The significantly positive ΔS# values found for both steps of the interaction reactions are consistent with a dissociative mechanism. [ABSTRACT FROM AUTHOR]

A correction to this paper has been published: https://doi.org/10.1007/s10853-021-06031-9 [ABSTRACT FROM AUTHOR]