Flavonoid Complexes as Promising Anticancer Metallodrugs

Flavonoid metal complexes commonly exhibit an improvement of biological activity compared to the parent ligands. This chapter is focused on the antioxidant and anticanc-cer properties of flavonoid metal complexes, in correlation with their binding ability to vital macromolecules such as nucleic acids and serum proteins. Perspectives for an adequate formulation of these complexes were also discussed

Nanoformulation as a Tool for Improve the Pharmacological Profile of Platinum and Ruthenium Anticancer Drugs

Cisplatin and analogs are used for the treatment of some type of cancers in combination with organic cytostatics. Also, two ruthenium (III) complexes are in clinical trials as anticancer drugs. In order to overcome toxicity and resistance associated with this therapy and/or enhance stability, a large variety of formulations based on organic, inorganic, or hybrid matrix were developed and tested both in vivo and in vitro. The best results were obtained for systems properly functionalized in order to enhance the metal content and/or to specific target the tumor tissue through overexpressed receptors

molecules Metal Complexes of Quinolone Antibiotics and Their Applications: An Update

Abstract: Quinolones are synthetic broad-spectrum antibiotics with good oral absorption and excellent bioavailability. Due to the chemical functions found on their nucleus (a carboxylic acid function at the 3-position, and in most cases a basic piperazinyl ring (or another N-heterocycle) at the 7-position, and a carbonyl oxygen atom at the 4-position) quinolones bind metal ions forming complexes in which they can act as bidentate, as unidentate and as bridging ligand, respectively. In the polymeric complexes in solid state, multiple modes of coordination are simultaneously possible. In strongly acidic conditions, quinolone molecules possessing a basic side nucleus are protonated and appear as cations in the ionic complexes. Interaction with metal ions has some important consequences for the solubility, pharmacokinetics and bioavailability of quinolones, and is also involved in the mechanism of action of these bactericidal agents. Many metal complexes with equal or enhanced antimicrobial activity compared to the parent quinolones were obtained. New strategies in the design of metal complexes of quinolones have led to compounds with anticancer activity. Analytical applications of complexation with metal ions were oriented toward two main directions: determination of quinolones based on complexation with metal ions or, reversely, determination of metal ions based on complexation with quinolones

Ruthenium Complexes in the Fight against Pathogenic Microorganisms. An Extensive Review

The widespread use of antibiotics has resulted in the emergence of drug-resistant populations of microorganisms. Clearly, one can see the need to develop new, more effective, antimicrobial agents that go beyond the explored ‘chemical space’. In this regard, their unique modes of action (e.g., reactive oxygen species (ROS) generation, redox activation, ligand exchange, depletion of substrates involved in vital cellular processes) render metal complexes as promising drug candidates. Several Ru (II/III) complexes have been included in, or are currently undergoing, clinical trials as anticancer agents. Based on the in-depth knowledge of their chemical properties and biological behavior, the interest in developing new ruthenium compounds as antibiotic, antifungal, antiparasitic, or antiviral drugs has risen. This review will discuss the advantages and disadvantages of Ru (II/III) frameworks as antimicrobial agents. Some aspects regarding the relationship between their chemical structure and mechanism of action, cellular localization, and/or metabolism of the ruthenium complexes in bacterial and eukaryotic cells are discussed as well. Regarding the antiviral activity, in light of current events related to the Covid-19 pandemic, the Ru (II/III) compounds used against SARS-CoV-2 (e.g., BOLD-100) are also reviewed herein

Improvement in the Pharmacological Profile of Copper Biological Active Complexes by Their Incorporation into Organic or Inorganic Matrix

Every year, more Cu(II) complexes are proven to be biologically active species, but very few are developed as drugs or entered in clinical trials. This is due to their poor water solubility and lipophilicity, low stability as well as in vivo inactivation. The possibility to improve their pharmacological and/or oral administration profile by incorporation into inorganic or organic matrix was studied. Most of them are either physically encapsulated or conjugated to the matrix via a moiety able to coordinate Cu(II). As a result, a large variety of species were developed as delivery carriers. The organic carriers include liposomes, synthetic or natural polymers or dendrimers, while the inorganic ones are based on carbon nanotubes, hydrotalcite and silica. Some hybrid organic-inorganic materials based on alginate-carbonate, gold-PEG and magnetic mesoporous silica-Schiff base were also developed for this purpose

Bucureºti) ♦ 61♦ Nr

A new and rapid synthesis method of azole aminals is described. Starting from pyrazole

Quinolone Complexes with Lanthanide Ions: An Insight into their Analytical Applications and Biological Activity

Quinolones comprise a series of synthetic bactericidal agents with a broad spectrum of activity and good bioavailability. An important feature of these molecules is their capacity to bind metal ions in complexes with relevant biological and analytical applications. Interestingly, lanthanide ions possess extremely attractive properties that result from the behavior of the internal 4f electrons, behavior which is not lost upon ionization, nor after coordination. Subsequently, a more detailed discussion about metal complexes of quinolones with lanthanide ions in terms of chemical and biological properties is made. These complexes present a series of characteristics, such as narrow and highly structured emission bands; large gaps between absorption and emission wavelengths (Stokes shifts); and long excited-state lifetimes, which render them suitable for highly sensitive and selective analytical methods of quantitation. Moreover, quinolones have been widely prescribed in both human and animal treatments, which has led to an increase in their impact on the environment, and therefore to a growing interest in the development of new methods for their quantitative determination. Therefore, analytical applications for the quantitative determination of quinolones, lanthanide and miscellaneous ions and nucleic acids, along with other applications, are reviewed here

DETERMINATION OF FLUOXETINE HYDROCHLORIDE VIA ION PAIR COMPLEXATION WITH ALIZARIN RED S

Two UV-Vis spectrophotometric methods and one fluorimetric method have been developed for the quantitative determination of fluoxetine hydrochloride in bulk and pharmaceutical formulations. These methods are based on the ion pair complex formation between alizarin red S and fluoxetine hydrochloride. In the first method (method A), the yellow-coloured complex obtained in acidic medium was extracted with chloroform, and the absorbance of chloroformic solution was measured at 425 nm. Beer’s law limits (9.5 – 48 µg/mL), the molar absorptivity (5256 L · mol-1· cm-1), and the complex composition (1:1) were determined. In the second method (method B), the yellow complex fluoxetine – alizarin red S extracted in chloroform was broken in alkaline medium, and the absorbance of the resulting violet-coloured free dye was measured at 524 nm. A linear relationship was observed in the range 9.0 – 54 µg/mL. In the third method (method C) the fluorescence intensity of the fluoxetine – alizarin red S complex, obtained in the same manner as for method A, was measured at 594 nm after excitation at 425 nm. The fluorescence intensity was proportional to the drug concentration in the linear range of 2.7-10.2 µg/mL. The limits of detection and quantification have also been calculated. Furthermore, the proposed methods have been successfully applied for the assay of the drug in pharmaceutical dosage forms

Synthesis and Characterization of Some New Complexes of Magnesium (II) and Zinc (II) with the Natural Flavonoid Primuletin

Two new metal complexes formulated as [Mg(L)2(H2O)2]·H2O (1) and [Zn(L)2(H2O)2]·0.5H2O (2), where HL = 5-hydroxyflavone (primuletin), have been synthesized and characterized by elemental and thermal analyses, molar conductance, IR, UV-Vis, 1H- and 13C-NMR, fluorescence and mass spectra. In solid state, complexes had shown higher fluorescence intensities comparing to the free ligand, and this behavior is appreciated as a consequence of the coordination process

Synthesis and Physico-Chemical Characterization of the Cu(II), Pd(II) and Ru(III) Complexes with Difloxacin

The growing interest in metal-quinolone complexes is sustained by a large number of compounds obtained and tested for antibacterial [1], antitumoral [1,2], antifungal [1], and antiparasitic [3] properties. [...