Antihuman Immunodeficiency Virus Type 1 (HIV-1) Activity of Rare Earth Metal Complexes of 4-Hydroxycoumarins in Cell Culture

What is holding back the development of antiviral metallodrugs? A literature overview and implications for SARS-CoV-2 therapeutics and future viral outbreaks

In light of the Covid-19 outbreak, this review brings together historical and current literature efforts towards the development of antiviral metallodrugs. Classical compounds such as CTC-96 and auranofin are discussed in depth, as pillars for future metallodrug development. From the recent literature, both cell-based results and biophysical assays against potential viral biomolecule targets are summarized here. The comprehension of the biomolecular targets and their interactions with coordination compounds are emphasized as fundamental strategies that will foment further development of metal-based antivirals. We also discuss other possible and unexplored methods for unveiling metallodrug interactions with biomolecules related to viral replication and highlight the specific challenges involved in the development of antiviral metallodrugs.

Lanthanide and transition metal complexes of bioactive coumarins: molecular modeling and spectroscopic studies

The present paper summarizes theoretical and spectroscopic investigations on a series of active coumarins and their lanthanide and transition metal complexes with application in medicine and pharmacy. Molecular modeling as well as IR, Raman, NMR and electronic spectral simulations at different levels of theory were performed to obtain important molecular descriptors: total energy, formation energy, binding energy, stability, conformations, structural parameters, electron density distribution, molecular electrostatic potential, Fukui functions, atomic charges, and reactive indexes. The computations are performed both in gas phase and in solution with consideration of the solvent effect on the molecular structural and energetic parameters. The investigations have shown that the advanced computational methods are reliable for prediction of the metal-coumarin binding mode, electron density distribution, thermodynamic properties as well as the strength and nature of the metal-coumarin interaction (not experimentally accessible) and correctly interpret the experimental spectroscopic data. Known results from biological tests for cytotoxic, antimicrobial, anti-fungal, spasmolytic and anti-HIV activities on the studied metal complexes are reported and discussed.

A Fast, Highly Efficient, and Green Protocol for Synthesis of Biscoumarins Catalyzed by Silica Sulfuric Acid Nanoparticles as a Reusable Catalyst

Silica sulfuric acid nanoparticles have been prepared and shown to efficiently catalyse the reaction between an aromatic aldehyde or phenylglyoxal and a 4-hydroxycoumarin at reflux in EtOH to afford the biscoumarin derivatives in high yield.

Synthesis and bioactive studies of complex 8-hydroxyquinolinato-bis-(salicylato) yttrium (III)

This paper reports the synthesis of a new bioactive complex, 8-hydroxyquinolinato-bis-(salicylato) yttrium (III) (HSAY), whose composition and structure were characterized by elemental analysis, IR spectra, thermogravimetric analysis, and X-ray diffraction. The power-time curves of the compounds HSAY, C(7)H(6)O(3), C(9)H(7)NO, and YCl(3)·6H(2)O on the growth metabolism of Schizosaccharomyces pombe (S. pombe) were determined at 32.00°C, respectively. The corresponding thermokinetics parameters, which include the microbial growth rate constant (κ), inhibition ratio (I), and half inhibition concentration (IC(50)), were also derived. The results showed that the generation time was 168.2 min, and all the compounds HSAY, C(7)H(6)O(3), C(9)H(7)NO, and YCl(3)·6H(2)O possessed good bioactivities on the growth metabolism of S. pombe, with the values of IC(50) being 0.055, 3.57, 0.057, and 1.35 mmol L(-1), respectively. The inhibition ability of these compounds above on the growth of the S. pombe has been observed to decrease in the order HSAY>C(9)H(7)NO>YCl(3)·6H(2)O>C(7)H(6)O(3).

Exposure to lanthanum compound diminishes LPS-induced inflammation-associated gene expression: involvements of PKC and NF-kappaB signaling pathways

Lanthanum chloride, a rare earth compound, possesses antibacterial and cellular immunity regulating properties. However, the underlying molecular mechanisms remain largely unknown. In this study, we examined the effects of lanthanum chloride on the production of nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha), the expression of inducible NO synthase (iNOS) and TNF-alpha in RAW 264.7 cells, a mouse macrophage cell line. We found that the LPS-elicited excessive production of NO and TNF-alpha in RAW 264.7 cells was inhibited significantly in the presence of lanthanum chloride, and the attenuation of iNOS and TNF-alpha occurred at mRNA level. Furthermore, the possible signaling components affected by lanthanum chloride in the pathway that lead to LPS-induced iNOS and TNF-alpha expression were explored. The results indicated the involvements of PKC/Ca(2+) and NF-kappaB in the attenuation of NO and pro-inflammatory cytokine production by lanthanum chloride. Our observations suggest a possible therapeutic application of this agent for treating inflammatory diseases.

In-vitro antibacterial, antifungal activity of some transition metal complexes of thiosemicarbazone Schiff base (HL) derived from N4-(7'-chloroquinolin-4'-ylamino) thiosemicarbazide

The synthetic, spectroscopic, and biological studies of Cu(II), Ni(II), Zn(II), Co(II), Mn(II), Fe(III) and Cr(III) complexes of N(4)-(7'-chloroquinolin-4'-ylamino)-N(1)-(2-hydroxy-benzylidene)thiosemicarbazone (HL) obtained by the reaction of N(4)-(7'-chloroquinolin-4'-ylamino)thiosemicarbazide with 2-hydroxybenzaldehyde. The structures of the complexes were determined on the basis of the elemental analyses, spectroscopic data (IR, electronic, (1)H and (13)C NMR and Mass spectra) along with magnetic susceptibility measurements, molar conductivity and thermogravimetric analyses. Electrical conductance measurement revealed the non-electrolytic nature of the complexes. The resulting colored products are mononuclear in nature. On the basis of the above studies, only one ligand was suggested to be coordinated to each metal atom by thione sulfur, azomethine nitrogen and phenolic oxygen to form mononuclear complexes in which the thiosemicarbazone behaves as a monobasic tridendate ligand. The ligand and its metal complexes were tested against Gram + ve bacteria (Staphylococcus aureus), Gram - ve bacteria (Escherichia coli), fungi (Candida albicans) and (Fusarium solani). The tested compounds exhibited significant activity.