Metal Complexation for the Rational Design of Gemcitabine Formulations in Cancer Therapy.

Nanoformulation of chemotherapies represents a promising strategy to enhance outcomes in cancer therapy. Gemcitabine is a chemotherapeutic agent approved by the Food and Drug Administration for the treatment of various solid tumors. Nevertheless, its therapeutic effectiveness is constrained by its poor metabolic stability and pharmacokinetic profile.

Metronidazole Interaction with Cu and Zn: Speciation Study in Aqueous Solution and Biological Activity Evaluation.

Metronidazole (2-methyl-5-nitro-1-imidazole-1-ethanol, MNZ) is a well-known and widely used drug for its excellent activity against various anaerobic bacteria and protozoa. The purpose of this study is to elucidate the ability of MNZ to form metal complexes with Cu and Zn and to demonstrate that complexation increases its bioactivity profile against different pathogenic microorganisms. The interaction of MNZ with Cu and Zn was investigated in NaCl aqueous solution under different conditions of temperature (15, 25, and 37 °C) and ionic strength (0.

Experimental and computational study on morin and its complexes with Mg, Mn, Zn, and Al: Coordination and antioxidant properties.

Morin (MRN), an intriguing bioflavonol, has received increasing interest for its antioxidant properties, as have its metal complexes (M-MRN). Understanding their antioxidant behavior is critical to assess their pharmaceutical, nutraceutical potential, and therapeutic impact in the design of advanced antioxidant drugs. To this end, knowing the speciation of different H-MRN and M-MRN is pivotal to understand and compare their antioxidant ability.

Screen-Printed Carbon Electrodes with Cationic Cyclodextrin Carbon Nanotubes and Ferrocenyl-Carnosine for Electrochemical Sensing of Hg(II).

The study reports the use of nanoassembly based on cationic cyclodextrin carbon nanotubes (CNT-CDs) and ferrocenylcarnosine (FcCAR) for electrochemical sensing of Hg(II) in aqueous solution. β-cyclodextrins (CDs) were grafted onto CNTs by a click chemistry reaction between heptakis-(6-azido-6-deoxy)-β-cyclodextrin and alkyne-terminated CNTs. The cationic amine groups on the CD units were produced by the subsequent reduction of the residual nitrogen groups.

Aqueous chemistry of nalidixic acid and its complexes with biological relevant cations: A combination of potentiometric, UV spectrophotometric, MS and MS/MS study.

Nalidixic acid (NAL) is a broad-spectrum antimicrobial widely used for urinary tract infections. As demonstrated, complexation of NAL with Zn, Mn and Cu was often used to get new formulations with an enhanced efficiency and potency. Therefore, the elucidation of behavior of NAL in solution and of its interaction with metal cations are crucial to better understand the influence of complexation on NAL efficiency and to find the optimal conditions to propose novel formulations.

Thermodynamic and voltammetric study on carnosine and ferrocenyl-carnosine.

A potentiometric study on the interactions of L-carnosine (CAR) (2-[(3-aminopropanoyl)amino]-3-(1-imidazol-5-yl)propanoic acid) with two toxic metal cations, Hg and Cd, is reported here. The elucidation of the metal (M)-CAR interactions in aqueous solution highlighted the speciation model for each system, the dependence of the formation constants of the complex species on ionic strength (0.15 ≤ /mol L ≤ 1) and temperature (288.

From speciation study to removal of Pb from natural waters by a carnosine-based polyacrylamide/azlactone copolymer.

A deep speciation study on L-carnosine (CAR) and Pb system was performed in aqueous solution with the aim to assess its potential use as a sequestering agent of metal cation. To determine the best conditions for Pb complexation, potentiometric measurements were carried out over a wide range of ionic strength (0.15 ≤ I/≤ 1 mol/L) and temperature (15 ≤ T/°C ≤ 37), and thermodynamic interaction parameters (logβ, ΔH, ΔG and TΔS) were determined.

Study on Metronidazole Acid-Base Behavior and Speciation with Ca for Potential Applications in Natural Waters.

Metronidazole () is an antibiotic widely used for the treatment of various infectious diseases and as an effective pesticide agent for the cultivation of chickens and fish. Its high resistance to purification processes and biological activity has led to the classification of as an emerging contaminant. A speciation study, aimed to define the acid-base properties of and its interaction with Ca, commonly present in natural waters, is reported.

Metal-Based Compounds in Antiviral Therapy.

In recent years, the study of metal complexes and metal-based nanomaterials has aroused particular interest, leading to the promotion of new effective systems for the abatement of various viral diseases. Starting from the analysis of chemical properties, this review focuses on the employment of metal-based nanoparticles as antiviral drugs and how this interaction leads to a substantial enhancement in antiviral activity. The use of metal-based antiviral drugs has also spread for the formulation of antiviral vaccines, thanks especially to the remarkable adjuvant activities of some of the metal complexes.

Speciation Study on O-Phosphorylethanolamine and O-Phosphorylcholine: Acid-Base Behavior and Mg Interaction.

In the present study, the acid-base behavior of compounds constituting the headgroups of biomembranes, O-phosphorylethanolamine (), and O-phosphorylcholine () was investigated by potentiometric titrations in NaCl aqueous solutions at different temperatures (15 ≤ /°C ≤ 37) and ionic strength (0.15 ≤ /mol L ≤ 1) values. The complexation properties and the speciation of these ligands with Mg were defined under different temperatures (15 ≤ /°C ≤ 37) and = 0.

molecular dynamics simulations and experimental speciation study of levofloxacin under different pH conditions.

Levofloxacin is an extensively employed broad-spectrum antibiotic belonging to the fluoroquinolone class. Despite the extremely wide usage of levofloxacin for a plethora of diseases, the molecular characterization of this antibiotic appears quite poor in the literature. Moreover, the acid-base properties of levofloxacin - crucial for the design of efficient removal techniques from wastewaters - have never extensively been investigated so far.

Oxazolidinone Antibiotics: Chemical, Biological and Analytical Aspects.

This review covers the main aspects concerning the chemistry, the biological activity and the analytical determination of oxazolidinones, the only new class of synthetic antibiotics advanced in clinical use over the past 50 years. They are characterized by a chemical structure including the oxazolidone ring with the configuration of substituent at C5, the acylaminomethyl group linked to C5 and the -aryl substituent. The synthesis of oxazolidinones has gained increasing interest due to their unique mechanism of action that assures high antibiotic efficiency and low susceptibility to resistance mechanisms.

Ca Complexation With Relevant Bioligands in Aqueous Solution: A Speciation Study With Implications for Biological Fluids.

A speciation study on the interaction between Ca and ligands of biological interest in aqueous solution is reported. The ligands under study are l-cysteine (), d-penicillamine (), reduced glutathione (), and oxidized glutathione (). From the elaboration of the potentiometric experimental data the most likely speciation patterns obtained are characterized by only protonated species with a 1:1 metal to ligand ratio.

Binding ability of arsenate towards Cu and Zn: thermodynamic behavior and simulation under natural water conditions.

A study on the sequestering ability between arsenate, AsO43-, and Cu2+ and Zn2+ in aqueous solution is reported. The results of the elaboration of potentiometric data include only species with 1 : 1 metal to ligand ratio for Cu2+-arsenate system, namely CuLH2, CuLH, CuL, and CuLOH (L = AsO43-). For the Zn2+-arsenate system, a speciation model with only two species with both 1 : 1 and 1 : 2 metal to ligand ratios was obtained, namely ML and ML2.

Interaction of Ampicillin and Amoxicillin with Mn: A Speciation Study in Aqueous Solution.

A potentiometric and UV spectrophotometric investigation on Mn-ampicillin and Mn-amoxicillin systems in NaCl aqueous solution is reported. The potentiometric measurements were carried out under different conditions of temperature (15 ≤ /°C ≤ 37). The obtained speciation pattern includes two species for both the investigated systems.

Complexation of As(III) by phosphonate ligands in aqueous fluids: Thermodynamic behavior, chemical binding forms and sequestering abilities.

In recent years, the contamination of water by arsenic reached alarming levels in many countries of the world, attracting the interest of many researchers engaged in testing methodologies able to remove this harmful pollutant. An important aspect that must be taken into consideration is the possibility to find arsenic in different chemical forms which could require different approaches for its removal. At this aim, a speciation analysis appears to be crucial for better understanding the behavior of arsenic species in aqueous solutions, especially in presence of compounds with marked chelating properties.

Arsenic-nucleotides interactions: an experimental and computational investigation.

Albeit arsenic As(iii) is a well-known carcinogenic contaminant, the modalities by which it interacts with living organisms are still elusive. Details pertaining to the binding properties of As(iii) by common nucleotides such as AMP, ADP and ATP are indeed mostly unknown. Here we present an investigation, conducted via experimental and quantum-based computational approaches, on the stability of the complexes formed by arsenic with those nucleotides.

Removal of As(III) from Biological Fluids: Mono- versus Dithiolic Ligands.

Arsenic is one of the inorganic pollutants typically found in natural waters, and its toxic effects on the human body are currently of great concern. For this reason, the search for detoxifying agents that can be used in a so-called "chelation therapy" is of primary importance. However, to the aim of finding the thermodynamic behavior of efficient chelating agents, extensive speciation studies, capable of reproducing physiological conditions in terms of pH, temperature, and ionic strength, are in order.

Interaction between As(III) and Simple Thioacids in Water: An Experimental and ab Initio Molecular Dynamics Investigation.

Albeit arsenic compounds are ubiquitous in aqueous solutions, the speciation of such a pollutant in natural water mainly depends on its binding capabilities with specific molecules. The features of most of the interactions of arsenic complexes can be established in solution, but the data related to the stability of the formed species, essentially depending on the concentration of the ligands, are elusive. For this reason, here, we report on a series of investigations where diverse approaches are combined together in order to characterize the behavior of As(III) species in aqueous solutions where simple chelating agents, such as thiolactic and thiomalic acids, are solvated.

Stability of hydrolytic arsenic species in aqueous solutions: Asvs. As.

Notwithstanding the fact that arsenic compounds are ubiquitous in the As3+ and As5+ forms in aqueous solutions, most of the microscopic features underlying the conditions of the hydrolysis steps are completely unknown. This way, a first-principles description of the fundamental behaviour of common arsenic species in natural waters and biological fluids is still lacking. Here we report on a synergistic computational and experimental investigation on As3+ and As5+ speciation in aqueous solution under both standard and sizably different alkaline circumstances.

Study of Al interaction with AMP, ADP and ATP in aqueous solution.

The interaction of Al and nucleotide ligands, namely adenosine-5'-monophosphate, (AMP), adenosine-5'-diphosphate, (ADP), adenosine-5'-triphosphate, (ATP), has been studied in aqueous solution at T = 298.15 K and I = 0.15 mol L in NaCl (only for Al-ATP system at I = 0.

Thermodynamic parameters for the protonation and the interaction of arsenate with Mg, Ca and Sr: Application to natural waters.

Thermodynamic parameters for the protonation of AsO and for the interaction with Mg, Ca and Sr were reported, comprehensive also of their dependence on ionic strength, considering the 0.1 ≤ I ≤ 1 M range and using NaCl as background salt. The same speciation models were obtained for Mg, Ca and Sr systems, with the formation of three different species: ML, MLH and MLH (L = AsO).

Thermodynamic and spectroscopic study of Al interaction with glycine, l-cysteine and tranexamic acid in aqueous solution.

In this paper a thermodynamic and spectroscopic study on the interaction between Al and glycine (Gly), l-cysteine (Cys), tranexamic acid (Tranex) is reported. Speciation models have been obtained by processing potentiometric titration data to determine stability constants of the species formed in aqueous solution at T=298.15K, 0.