Nuclease-like metalloscissors: Biomimetic candidates for cancer and bacterial and viral infections therapy

Despite the extensive and rapid discovery of modern drugs for treatment of cancer, microbial infections, and viral illnesses; these diseases are still among major global health concerns. To take inspiration from natural nucleases and also the therapeutic potential of metallopeptide antibiotics such as the bleomycin family, artificial metallonucleases with the ability of promoting DNA/RNA cleavage and eventually affecting cellular biological processes can be introduced as a new class of therapeutic candidates. Metal complexes can be considered as one of the main categories of artificial metalloscissors, which can prompt nucleic acid strand scission. Accordingly, biologists, inorganic chemists, and medicinal inorganic chemists worldwide have been designing, synthesizing and evaluating the biological properties of metal complexes as artificial metalloscissors. In this review, we try to highlight the recent studies conducted on the nuclease-like metalloscissors and their potential therapeutic applications. Under the light of the concurrent Covid-19 pandemic, the human need for new therapeutics was highlighted much more than ever before. The nuclease-like metalloscissors with the potential of RNA cleavage of invading viral pathogens hence deserve prime attention.

Cu(II) complex with auxin (3-indoleacetic acid) and an aromatic planar ligand: synthesis, crystal structure, biomolecular interactions and radical scavenging activity

A novel water soluble ternary copper(II) complex,-[Cu₂(phen)₂(3-IAA)₂(H₂O)](ClO₄)₂·H₂O-(phen: 1,10-phenanthroline, 3-IAA: 3-indoleacetic acid), has been synthesized and characterized by elemental CHN analysis, ESI-TOF, FTIR and single-crystal X-ray diffraction techniques. Interaction of the complex with calf thymus DNA (CT-DNA) has been investigated by absorption spectral titration, ethidium bromide (EB) and Hoechst 33258 displacement assay. The interactions between the complex and bovine serum albumin (BSA) were investigated by electronic absorption and fluorescence spectroscopy methods. The experimental results indicate that the fluorescence quenching mechanism between the complex and BSA is a static quenching process. The Stern-Volmer constants, binding constants, binding sites and the corresponding thermodynamic parameters (ΔG, ΔH, ΔS) of BSA + complex systems were determined at different temperatures. The binding distance between the complex and BSA was calculated according to Förster non-radiation energy transfer theory (FRET). The effect of the complex on the conformation of BSA was also examined using synchronous, two dimensional (2D) and three dimensional (3D) fluorescence spectroscopy. Furthermore, the oxygen radical scavenging activity of the complex was determined in terms of IC₅₀, using the DPPH and H₂O₂ method, to show that it particularly enables electron loss from radical species. This study highlights the importance of indole and moieties in the development of antioxidant agents. A potent drug candidate novel water soluble ternary copper(II) complex,-[Cu₂(phen)₂(3-IAA)₂(H₂O)] (ClO₄)₂·H₂O-(phen: 1,10-phenanthroline, 3-IAA: 3-indoleacetic acid), has been synthesized and characterized by elemental CHN analysis, FTIR, ESI-MS and single-crystal X-ray diffraction techniques. The complex has been tested for in vitro biomacromolecular interactions by spectroscopic methods. Furthermore, radical scavenging activities of the complex were also investigated.

Palladium(ii) complexes bearing 1-iminothiolate-3,5-dimethylpyrazoles: synthesis, cytotoxicity, DNA binding and enzymatic inhibition studies

This work describes the enzymatic inhibitory activity of four novel Pd(ii) complexes towards topoisomerase IIα and cathepsins B and L.In silicostudies agree well with the enhancedin vitrocathepsin B inhibition induced by compound4(58% at 10 μM).