Investigation of Gallium(III) Complexes with Thiouracil Derivatives: Effects of pH on Coordination and Stability.

This study explores the formation and properties of new complexes involving gallium(III) and thiouracil derivatives-2-thiouracil (TU), 6-methyl-2-thiouracil (MTU), 6-propyl-2-thiouracil (PTU), 5-carboxy-2-thiouracil (CTU), and 6-methoxymethyl-2-thiouracil (MMTU). Conducted in aqueous solutions at relatively low concentrations, this research enabled the formation of soluble complexes, identified and described here for the first time. The influence of metal-to-ligand ratios on species distribution and their fluorescence properties was examined through potentiometric titration, alongside visible and fluorescence spectroscopy.

Spectroscopic Studies of Lanthanide(III) Complexes with L-Malic Acid in Binary Systems.

Binary systems of lanthanide ions (La, Nd, Gd, Ho, Tb, and Lu) with L-malic acid in molar ratios of 1:1 and 1:2 were studied. This study was carried out in aqueous solutions, and the composition of the formed complexes was confirmed using computer data analysis. The overall stability constants of the complexes and the equilibrium constants of the reaction were determined.

Deciphering the Impact of Nucleosides and Nucleotides on Copper Ion and Dopamine Coordination Dynamics.

The mode of coordination of copper(II) ions with dopamine (DA, L) in the binary, as well as ternary systems with Ado, AMP, ADP, and ATP (L') as second ligands, was studied with the use of experimental-potentiometric and spectroscopic (VIS, EPR, NMR, IR)-methods and computational-molecular modeling and DFT-studies. In the Cu(II)/DA system, depending on the pH value, the active centers of the ligand involved in the coordination with copper(II) ions changed from nitrogen and oxygen atoms (CuH(DA), Cu(DA)), via nitrogen atoms (CuH(DA)), to oxygen atoms at strongly alkaline pH (Cu(DA)). The introduction of L' into this system changed the mode of interaction of dopamine from oxygen atoms to the nitrogen atom in the hydroxocomplexes formed at high pH values.

Thermodynamic Studies of Complexes in Cu(II)/Uridine-5'-Diphosphoglucuronic Acid System.

A binary system of uridine-5'-diphosphoglucuronic acid with copper (II) ions was studied. Potentiometric studies in aqueous solutions using computer data analysis were carried out. The pH of dominance, the overall stability constants (log), and the equilibrium constants of the formation reaction (log) were determined for each complex compound formed in the studied system.

Advancing oral health: Harnessing the potential of chitosan and polyphenols in innovative mouthwash formulation.

This paper explores the therapeutic perspectives of polyphenols and chitosan as potential anticancer agents in the mouthwash formulations. Taking into account the high incidence of squamous cell carcinoma (SCC) among oral cancers, this discussion will concentrate on the potential advantages of these compounds in oral care, focusing on their impact on improving oral health and cancer prevention. According to the data, it appears that the mixture of BACs extract and chitosan may increase the efficiency of the apoptosis of cancer cells while reducing the undesired side effects.

Biocoordination reactions in copper(II) ions and phosphocholine systems including pyrimidine nucleosides and nucleotides.

The complexation reactions of phosphocholine and pyrimidine nucleosides as well as nucleotides with copper(II) ions were studied in the water system. Using potentiometric methods and computer calculations, the stability constants of the species were determined. Using spectroscopic methods such as UV-vis, EPR, C NMR, P NMR, FT-IR and CD, the coordination mode was established for complexes created in pH range 2.

Synthesis and evaluation of radiolabeled porphyrin derivatives for cancer diagnoses and their nonradioactive counterparts for photodynamic therapy.

Radioiodinated porphyrin derivatives and the corresponding nonradioactive iodine introduced compounds, [I]I-TPP ([I]3), [I]I-l-tyrosine-TPP ([I]9), I-TPP (3), and I-l-tyrosine-TPP (9) were designed, synthesized, and evaluated by and experiments. In cytotoxicity assays, 3 and 9 exhibited significant cytotoxicity under light conditions but did not show significant cytotoxicity without light irradiation. Biodistribution experiments with [I]3 and [I]9 showed similar distribution patterns with high retention in tumors.

Coordination Chemistry of Phosphate Groups in Systems Including Copper(II) Ions, Phosphoethanolamine and Pyrimidine Nucleotides.

The activity of phosphate groups of phosphoethanolamine and pyrimidine nucleotides (thymidine 5-monophosphate, cytidine 5-monophosphate and uridine 5'monophosphate) in the process of complexation metal ions in aqueous solution was studied. Using the potentiometric method with computer calculation of the data and spectroscopic methods such as UV-Vis, EPR, C and P NMR as well as FT-IR, the overall stability constants of the complexes as well as coordination modes were obtained. At lower pH, copper(II) ions are complexed only by phosphate groups, whereas the endocyclic nitrogen atom of nucleotides has been identified as a negative center interacting with the -NH groups of phosphoethanolamine.

Christmas Tree Bio-Waste as a Power Source of Bioactive Materials with Anti-Proliferative Activities for Oral Care.

According to the American Cancer Society, roughly 54,000 new cases of oral cavity or oropharyngeal cancers have been detected in the United States of America in 2021, and they will cause about 10,850 deaths. The main therapies for cancer management, such as surgery and radio- and chemotherapy, have some own benefits, albeit they are often destructive for surrounding tissues; thus, deep investigations into non-surgical treatments for oral cavities are needed. Biologically active compounds (BACs) extracted from European Spruce needles were analyzed to determine the total phenolic and flavonoid content and were used as additional ingredients for oral hygiene products.

Synthesis and evaluation of radiogallium-labeled long-chain fatty acid derivatives as myocardial metabolic imaging agents.

Since long-chain fatty acids work as the primary energy source for the myocardium, radiolabeled long-chain fatty acids play an important role as imaging agents to diagnose metabolic heart dysfunction and heart diseases. With the aim of developing radiogallium-labeled fatty acids, herein four fatty acid-based tracers, [67Ga]Ga-HBED-CC-PDA, [67Ga]Ga-HBED-CC-MHDA, [67Ga]Ga-DOTA-PDA, and [67Ga]Ga-DOTA-MHDA, which are [67Ga]Ga-HBED-CC and [67Ga]Ga-DOTA conjugated with pentadecanoic acid (PDA) and 3-methylhexadecanoic acid (MHDA), were synthesized, and their potential for myocardial metabolic imaging was evaluated. Those tracers were found to be chemically stable in 0.

Influence of d-Electron Divalent Metal Ions in Complex Formation with L-Tartaric and L-Malic Acids.

Binary complexes of α-hydroxy acids (L-Tartaric acid and L-Malic acid) with d-electron metal ions (copper, cobalt, nickel) were investigated. Potentiometric measurements have been performed in aqueous solution with computer analysis of the data for determination of the stability constants of complexes formed in the studied systems. The coordination mode of the complexes was defined using spectroscopic methods: electron paramagnetic resonance (EPR), ultraviolet-visible (UV-Vis), circular dichroism (CD), and infrared (IR).

The Influence of pH on Complexation Process of Copper(II) Phosphoethanolamine to Pyrimidine Nucleosides.

The influence of pH on the complex formation of phosphoethanolamine and pyrimidine nucleosides (uridine, cytidine and thymidine) with copper(II) ions was studied. All investigations were performed in aqueous solution. The overall stability constants of the complexes and non-covalent compounds were obtained using the potentiometric method with computer calculation of the data.

The Effect of pH on the Size of Silver Nanoparticles Obtained in the Reduction Reaction with Citric and Malic Acids.

In colloidal methods, the morphology of nanoparticles (size and shape) as well as their stability can be controlled by changing the concentration of the substrate, stabilizer, adding inorganic salts, changing the reducer/substrate molar ratio, and changing the pH and reaction time. The synthesis of silver nanoparticles was carried out according to the modified Lee and Meisel method in a wide pH range (from 2.0 to 11.

Thermodynamic and Spectroscopic Studies of the Complexes Formed in Tartaric Acid and Lanthanide(III) Ions Binary Systems.

Binary complexes of tartaric acid with lanthanide(III) ions were investigated. The studies have been performed in aqueous solution using the potentiometric method with computer analysis of the data for detection of the complexes set, determination of the stability constants of these compounds. The mode of the coordination of complexes found was determined using spectroscopy, which shows: Infrared, circular dichroism, ultraviolet, visible as well as luminescence spectroscopy.

New coordination compounds of citric acid and polyamines with lanthanide ions - potential application in monitoring the treatment of cancer diseases.

Non-covalent interaction in the binary systems of polyamines (putrescine, spermidine, spermine) with citric acid and complex formation in the binary as well as ternary systems of lanthanide(III) ions, citric acid and polyamine have been investigated. The studies were performed in aqueous solution. The overall stability constants of the complexes were determined using the potentiometric method with computer analysis of the data.

Coordination properties of ,'-bis(5-methylsalicylidene)-2-hydroxy-1,3-propanediamine with d- and f-electron ions: crystal structure, stability in solution, spectroscopic and spectroelectrochemical studies.

Template reaction between 5-methylsalicylaldehyde and 2-hydroxy-1,3-propanediamine in the presence of copper ion led to dinuclear and mononuclear copper(ii) complexes [CuL(CHCOO)(CHOH)](CHOH) (1) and [CuHL](CHOH) (2), where HL is ,'-bis(5-methylsalicylidene)-2-hydroxy-1,3-propanediamine. The result of the reactions between 5-methylsalicylaldehyde and 2-hydroxy-1,3-propanediamine in the presence of lanthanide ions and/or copper(ii) ion was ,'-bis(5-methylsalicylidene)-2-hydroxy-1,3-propanediamine (HL B) or [CuHL](CHOH) (2), respectively. Structures of the compounds were determined by single-crystal X-ray diffraction and physicochemical methods.

Carboxyl groups of citric acid in the process of complex formation with bivalent and trivalent metal ions in biological systems.

Binary complexes of citric acid (HL - protonated form, HL and HL - partly protonated forms, L - fully deprotonated) with d- and f-electron metal ions were investigated. The studies have been performed in aqueous solution using the potentiometric method with computer analysis of the data, electron paramagnetic resonance, infrared, visible as well as luminescence spectroscopies. The overall stability constants of the complexes were determined.

PVDF Membrane Morphology-Influence of Polymer Molecular Weight and Preparation Temperature.

In this study, we successfully prepared nine non-woven, supported polyvinylidene fluoride (PVDF) membranes, using a phase inversion precipitation method, starting from a 15 wt % PVDF solution in -methyl-2-pyrrolidone. Various membrane morphologies were obtained by using (1) PVDF polymers, with diverse molecular weights ranging from 300 to 700 kDa, and (2) different temperature coagulation baths (20, 40, and 60 ± 2 °C) used for the film precipitation. An environmental scanning electron microscope (ESEM) was used for surface and cross-section morphology characterization.

Smart Capsules for Lead Removal from Industrial Wastewater.

Ground and especially drinking water could be contaminated by heavy metal ions such as lead and chromium, or the metalloid arsenic, discarded from industrial wastewater. These heavy metal ions are regarded as highly toxic pollutants which could cause a wide range of health problems in case of a long-term accumulation in the body. Thus, there have been many efforts to reduce the concentration of lead ions in effluent wastewater.

Concentration and Fractionation of Polyphenols by Membrane Operations.

Background: This review aims to present the relevant background information and current research status in concentration of polyphenols using membrane technologies. The potential implementation of membrane separation to bioactive compounds like soluble phenolics from aqueous and organic solvent solutions is gaining increasing interest in the recent years. This review does not pretend to cover the abundant published literature on the subject, but to be representative for the observed tendencies in membrane processes applications for concentration of polyphenols derived from natural products.

Complexing ability of (-)-cytisine--synthesis, spectroscopy and crystal structures of the new copper and zinc complexes.

For the first time the NMR spectra of quinolizidine alkaloid with Cu(II) are studied. Structures of new complexes of (-)-cytisine with Cu(+2) and Zn(+2) cations are visualized, discussed in detail and characterized by spectroscopic methods: ESI-MS, NMR, UV-vis, EPR and crystallographic methods. In solution metal coordinates through the protonated nitrogen atoms of secondary amino groups (in piperidine ring) of cytisine molecule.

Spectroscopic, potentiometric and quantum-mechanical studies of S-(-)-nicotine complexes with Cu(II) ion.

Copper(II)-nicotine complexes with chelating perchlorate, nitrate, acetate and formate ligands have been synthesized and characterized in solid state by elemental analysis and FT-IR spectroscopy. Coordination of Cu(II) by nicotine molecule has been also studied in water solution of various pH by potentiometry and spectroscopic (VIS, EPR and NMR) methods. Furthermore, quantum-mechanical calculations helped elucidate the experimental data as they provided some information on the energetic of the possible interaction modes of Cu(II) with nicotine.

Equilibrium study on the interaction of phytic acid with polyamines and metal ions.

Interaction of phytic acid (myo-inositolhexakisphosphoric acid, IP) and polyamines (A = en, tn, Put, dien, 2,3-tri, 3,3-tri, Spd, 3,3,3-tet, spermine(Spm)) have been studied by potentiometric and (31)P-NMR techniques. The non-covalent interactions have led to the formation of stable molecular complexes of (IP)H(n)(A) type at the 1:1 molar ratio of the ligands, but of different numbers of protons. The IP protonation constants, stability constants of the molecular complexes and metal (Mg(2+)) complexes have been determined.

The effect of spermine concentration on the solution structure of complexes formed in copper(II)/adenosine 5'-triphosphate/phosphoserine system.

Quaternary systems of copper(II) complexes with adenosine 5'-triphosphate, O-phospho L-serine and with equimolar or excessive amount of spermine have been investigated. The studies have been performed in aqueous solution. Types of complexes and the overall stability constants have been determined using the potentiometric method with computer analysis of the data.