DNA and protein targeting 1,2,4-triazole based water soluble dinickel(II) complexes enhances antiproliferation and lactate dehydrogenase inhibition

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.

Triazole-Bridged Zinc Dinuclear Complexes: Mechanochemical Synthesis, Crystal Structure, and Biological Activity

Two zinc (Zn) complexes, [Zn₂(DAT)₂Cl₄] (I) and [Zn₂(DAT)₂(NO₃)₄] (II), were prepared by grinding 3,5-diamino-1,2,4-triazole (C₂H₅N₅, DAT) with Zn precursors such as ZnCl₂ and Zn(NO₃)₂, respectively. This solid-state reaction gives the corresponding Zn complex as the sole product in over 99% yield. This mechanochemical method promotes the selective formation of Zn complexes different from those obtained using the conventional solution-based route. The crystal structures of the two complexes were analyzed by single-crystal X-ray diffraction. Complex (I) crystallizes in the monoclinic space group P2₁/c, whereas complex (II) crystallizes in the triclinic space group P _1̅. Each complex is characterized by the presence of a characteristic DAT-bridged dimer with one DAT ligand per Zn atom, and the DAT ligand provides a bridge between the two Zn metals. All Zn centers of (I) and (II) adopted a slightly distorted tetrahedral geometry. Both complexes contain a hexanuclear Zn₂N₄ ring, but their ring structures are different. Complex (I) possesses a boat geometry, while complex (II) has a nearly planar structure. The Zn-bound chlorides of complex (I) form intermolecular N-H···Cl hydrogen bonds that link neighboring molecules. In complex (II), the O atoms in the nitrate groups are hydrogen-bonded to the DAT ligand via O···H-N linkages. Both complexes exhibit blue emissions in the solid state at ambient temperature. They were evaluated as anticancer agents in HeLa, NCCIT, and MCF-7 cancer cell lines, exhibiting promising anticancer activities.

Photochromic and molecular switching behaviour of new Schiff bases containing hydantoin rings: synthesis, characterization and crystal structures

Five new Schiff bases containing hydantoin rings were synthesized and showed photochromic and molecular switching behaviours.

Synthesis, characterization, anticancer and antimicrobial study of arene ruthenium(II) complexes with 1,2,4-triazole ligands containing an α-diimine moiety

The reaction of the ruthenium arene dimers [(η 6-arene)Ru(μ-Cl)Cl]2 (where arene=benzene or p-cymene) with the ligands 4-benzylidene-3,5-di(2′-pyridyl)-4-amino-1,2,4-triazole (L1 ), 2-methoxybenzylidene-3,5-di(2′-pyridyl)-4-amino-1,2,4-triazole (L2 ), 4-methylbenzylidene-3,5-di(2′-pyridyl)-4-amino-1,2,4-triazole (L3 ) and indole-3-carbaldehyde-3,5-di(2′-pyridyl)-4-amino-1,2,4-triazole (L4 ) in a 1:2 ratio gives the new complexes [(η 6-arene)RuCl(L)]+ [arene=C6H6 (with L=L1(1), L2(3), L4(7), with PF6 − as a counter ion, and L4 (6), with Cl− as a counter ion) or p-cymene with L=L1(2), L2(4), L3(5), L4(8) with PF6 − as a counter ion]. All complexes were fully characterized using 1H and 13C NMR, elemental analyses, UV/Vis and IR spectroscopy. The single crystal X-ray structures of ligand L2 and complex 1 have been determined. The structure of 1 has the Ru atom coordinated with the arene group and to the N,N′-bidentate ligand and to the Cl atom. The arene group occupies the apex, while the ligand and the Cl atom are at the base of a pseudo-octahedral three-legged piano stool. The cytotoxicity of these mononuclear complexes was established in the human epithelial colorectal adenocarcinoma cell line (Caco-2) and for selectivity in the non-cancerous human embryonic kidney cell line (HEK293), using 5-fluorouracil (5-FU) as the reference anticancer drug. Compounds 1 and 7 were relatively inactive toward the Caco-2 tumor cells (IC50>200), while complexes 2–5 showed moderate anti-proliferative properties (IC50>100–200). Compound 6, however, displayed better anti-proliferative properties with an IC50 value lower than that of the reference drug, 5-FU, and was therefore further investigated for its antimicrobial activity against six Gram-positive and four Gram-negative bacteria.

Design, synthesis and evaluation of a novel π–π stacking nano-intercalator as an anti-tumor agent

A strategy for designing safe and effective π–π stacking nano-intercalators as anti-tumor agents was presented for the first time.