Synthesis, structural characterization, DNA/protein binding and in vitro cytotoxicity of three structurally different organoruthenium metallates from single pot

Organoruthenium metallocycle induced mutation in gld-1 tumor suppression gene in JK1466 strain and appreciable lifespan expansion

Four Ru(II) complexes (A2-A5) were synthesized from the reaction of coumarin Schiff base ligands (7da2-tsc, 7da3-mtsc, 7da4-etsc and 7da5-ptsc) with [RuHCl(CO)(PPh3)3]. The compounds were characterized by FT-IR, UV-Vis, 1H, 13C and 31P NMR, mass spectrometry and crystallographic analysis. Calf Thymus DNA (CT-DNA) binding studies revealed the intercalative mode of binding of the complexes with DNA. The results of Bovine serum albumin (BSA) binding studies established the interaction between BSA followed static quenching mechanism. The cytotoxic effects of the complexes and the ligands were evaluated against breast (MCF-7 and MDA-MB-231) and lung carcinoma cell lines (A549 and NCI-H460) using MTT assay. Complex A4 demonstrated potent cytotoxic effects on both breast and lung cancer cells. Furthermore, morphological observations and FACS analysis showed the decrease in cell density by complex A4 by induced morphological changes and apoptotic body formation and cell death in both breast and lung cancer cells. Moreover, the invertebrate model Caenorhabditis elegans was employed to assess the in vivo anticancer activity of compound A4. The findings indicated that the treatment with A4 reduced tumor development and significantly extended organismal lifespan by 64 % in the tumoral strain JK1466 without adversely affecting essential physiological functions of the worm. Additionally, A4 demonstrated an upregulation of two crucial antioxidant defense genes. Overall, these results suggested that the compound A4 can be a potential candidate with novel chemotherapeutic applications.

Research Progress on the Biological Activities of Metal Complexes Bearing Polycyclic Aromatic Hydrazones

Due to the abundant and promising biological activities of aromatic hydrazones, it is of great significance to study the biological activities of their metal complexes for the research and development of metal-based drugs. In this review, we focus on the metal complexes of polycyclic aromatic hydrazones, which still do not receive much attention, and summarize the studies related to their biological activities. Although the large number of metal complexes in phenylhydrazone prevent them all from being summarized, the significant value of polycyclic aromatic hydrocarbons themselves (such as naphthalene and anthracene) as pharmacophores are also considered. Therefore, the bioactivities of the metal complexes of naphthylhydrazone and anthrahydrazone are focused on, and the recent research progress on the metal complexes of anthrahydrazone by the authors is also included. In terms of biological activities, these complexes mainly show antibacterial and anticancer activities, along with less bioactivities. The present review demonstrates that the structural design and bioactivities of these complexes are fundamental, which also indicates a certain structure-activity relationship (SAR) in some substructural areas. However, a systematic and comprehensive conclusion of the SAR is still not available, which suggests that more attention should be paid to the bioactivities of the metal complexes of polycyclic aromatic hydrazones since their potential in structural design and biological activity remains to be explored. We hope that this review will attract more researchers to devote their interest and energy into this promising area.

Synthesis of Novel Dinuclear N-Substituted 4-(Dimethylamino)benzaldehyde Thiosemicarbazonates of Rhenium(I): Formation of Four- and/or Five-Membered Chelate Rings, Conformational Analysis, and Reactivity

The reaction of fac-[ReX(CH₃CN)₂(CO)₃] (X = Cl, Br) with N-phenyl-[4-(dimethylamino)benzaldehyde] thiosemicarbazone (HL^A) or N-4-methoxybenzyl-[4-(dimethylamino)benzaldehyde] thiosemicarbazone (HL^B) under controlled synthetic conditions gave 4 mononuclear [ReX(HL)(CO)₃] (X = Cl, Br) and 16 dinuclear [Re₂L₂(CO)₆] compounds. These complexes were obtained as single crystals, and their structures were established by X-ray diffraction. The structural study of these dimers showed the formation of several solvates, the presence of linkage isomerism, and the stabilization of four- and/or five-membered chelate rings. The different ligand coordination modes (a new μ-κ²-S,N2:κ-N3 coordination mode for a thiosemicarbazone ligand was observed), the conformation of the thiosemicarbazone chain in each case, the formal symmetry of the dimers, and the role of the synthetic procedure in the stability of the different chelate rings were analyzed and are discussed. Theoretical calculations in the gas phase were performed for the dimers with the HL^A ligand in order to identify the thermodynamically most stable species. The behavior and structural stability of dimers in dimethyl sulfoxide and acetone solutions was investigated by ¹H NMR spectroscopy. The strength of the Re^I-L bond in solution was evidenced by the formation of [Re₂(L^NO₂)₂(CO)₆] and [Re(L^A)(py)(CO)₃] upon reaction of the corresponding dimer with concentrated nitric acid and pyridine, respectively.