Gallium (III) Complexes with 5-Bromosalicylaldehyde Benzoylhydrazones: In Silico Studies and In Vitro Cytotoxic Activity

Design, Synthesis and Cytotoxic Activity of Novel Salicylaldehyde Hydrazones against Leukemia and Breast Cancer

Despite the significant advancements in complex anticancer therapy, the search for new and more efficient specific anticancer agents remains a top priority in the field of drug discovery and development. Here, based on the structure-activity relationships (SARs) of eleven salicylaldehyde hydrazones with anticancer activities, we designed three novel derivatives. The compounds were tested in silico for drug-likeness, synthesized, and evaluated in vitro for anticancer activity and selectivity on four leukemic cell lines (HL-60, KE-37, K-562, and BV-173), one osteosarcomic cell line (SaOS-2), two breast adenocarcinomic cell lines (MCF-7 and MDA-MB-231), and one healthy cell line (HEK-293). The designed compounds were found to have appropriate drug likeness and showed anticancer activities in all cell lines tested; particularly, two of them exhibited remarkable anticancer activity in nanomolar concentrations on the leukemic cell lines HL-60 and K-562 and the breast cancer MCF-7 cells and extraordinary selectivity for the same cancer lines ranging between 164- and 1254-fold. The study also examined the effects of different substituents on the hydrazone scaffold and found that the 4-methoxy salicylic moiety, phenyl, and pyridinyl rings are the most appropriate for anticancer activity and selectivity of this chemical class.

Search for new antimicrobials: spectroscopic, spectrometric, and in vitro antimicrobial activity investigation of Ga(III) and Fe(III) complexes with aroylhydrazones

The in vitro antimicrobial activity of Fe(III) and Ga(III) complexes with N'-(2,3-dihydroxy-phenylmethylidene)-3-pyridinecarbohydrazide (H₂L¹), N'-(2,4-dihydroxy-phenyl-methylidene)-3-pyridinecarbohydrazide (H₂L²), N'-(2,5-dihydroxy-phenylmethylidene)-3-pyridinecarbohydrazide (H₂L³), N'-(2-hydroxy-3-methoxyphenyl-methylidene)-3-pyridine-carbohydrazide (H₂L⁴), N'-(2-hydroxy-4-methoxyphenylmethyl-idene)-3-pyridine-carbohydrazide (H₂L⁵), and N'-(2-hydroxy-5-methoxyphenylmethylidene)-3-pyridinecarbo-hydrazide (H₂L⁶) toward several Gram-positive strains of Staphylococcus aureus, a Gram-negative strain of Escherichia coli, and a yeast Candida albicans were investigated. Fe(III)-complexes do not possess antimicrobial activity against all tested strains at concentrations up to 10 mg mL^-1. Ga(III) complexes with dihydroxy derivatives showed selective activity, while the broadest range of antibacterial and antifungal activities was observed for complex with 2-hydroxy-3-methoxy-derivative, ligand H₂L⁵. In addition, the coordination properties of ligands H₂L¹-H₂L³ in solution were investigated by UV-Vis spectroscopy. The stability constants (logK) for Ga(III)-H₂L 1:1 complexes in MeOH/H₂O 1/1 at pH 2.52 were determined, and amounted to 5.8, 5.68, and 4.7, respectively. Detailed characterization of complexes was performed by high-resolution mass spectrometry. The fragmentation pathways for dimer [Fe₂(L¹)₂]²⁺, [Fe(HL)₂]⁺, [Ga(HL²)₂]⁺ and adduct ions are given. The comparison with analogue Ga(III) and Fe(III) complexes with compounds H₂L⁴-H₂L⁶ was made as well.