Synthesis and antibacterial activity of novel Schiff bases of thiosemicarbazone derivatives with adamantane moiety

Abstract

Increased bacterial resistance to antibiotics is a major threat to human health, and it is particularly important to develop novel antibiotic drugs. Here, we designed a series of Schiff base thiosemicarbazone derivatives containing an adamantane moiety, and carried out structural characterization of the compounds and in vitro antibacterial activity tests. Compound 7e was as effective as the commonly-used antibiotic ampicillin against the Gram-negative bacterium Escherichia coli, and compound 7g had a good inhibitory effect against Gram-positive Bacillus subtilis. These ndings provide data for the development of better thiosemicarbazone antibacterial agents.

Theoretical, in Vitro Antiproliferative, and in Silico Molecular Docking and Pharmacokinetics Studies of Heteroleptic Nickel(II) and Copper(II) Complexes of Thiosemicarbazone‐Based Ligands and Pefloxacin

“…A methanolic solution of metal(II) chloride (0.75 mmol) was added dropwise to an equimolar amount of N 4 -substituted TSCs (L [1][2][3][4][5][6] ) dissolved in distilled water (10 mL) followed by the addition of pefloxacin mesylate (1.5 mmol) dissolved in distilled water (15 mL) along with NaOH (1.5 mmol), with continuous stirring. The resulted product was stirred for 2 h, refluxed for 4-5 h, and then kept as such at room temperature to evaporate slowly.…”

“…The molecular docking studies of the metal(II) complexes (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) were carried out to predict the binding modes and affinities of the complexes with H-ras (121 p), an oncogenic protein, using the software AutoDock (ADT) version 1.5.7. All the AutoDock parameters were set in accordance with the specifications described in our previous article.…”

“…The heteroleptic nickel(II) and copper(II) complexes of the type [M(L [1][2][3][4][5][6] )(Pfx) 2 ] (1-12) were synthesized by the reaction of N 4 substituted thiosemicarbazones with pefloxacin in the presence of metal(II) salt (NiCl 2 .6H 2 O/CuCl 2 .2H 2 O) in methanol and water (Scheme 1). The complexes are air-stable solids, soluble in DMF and DMSO, partially soluble in acetonitrile, methanol and ethanol, and insoluble in diethyl ether and water.…”

“…During the last few decades, thiosemicarbazones (TSCs) and their metal complexes have been the center of interest for biochemical scientists due to their different coordination modes, selectivity and stability towards metal ions, and the multitude of biological activities such as antioxidant, antimicrobial, antidiabetic, anti HIV, antiinflammatory, antiproliferative, antiparasitic, insecticidal and herbicidal activities. [1][2][3][4][5][6][7][8][9] The coordination of metal ions with active pharmacological molecules enhances the biological efficacy of the complexes as compared to precursor molecules and metal ions. [10][11][12] As a result of chelation, the metal ion's positive charge is distributed among the ligand's donor groups, leading to an increase in electron delocalization throughout the chelate ring, which enhances cell penetration due to the increased lipophilicity of the complex.…”

“…Over the past few decades, the structural and biological activities of metal complexes of several fluoroquinolones have been explored by researchers, and the observations showed that the metal complexes of fluoroquinolones show improved water solubility and easy transportation in the bloodstream than the free fluoroquinolones. This research aimed to synthesize a new series of heteroleptic metal(II) complexes of N 4 substituted thiosemicarbazones and pefloxacin. The synthesized heteroleptic metal(II) complexes were investigated for their in vitro antiproliferative efficacy against three human breast cancerous (T47D, MDA-MB-231 and MCF-7) and one nontumorigenic human breast epithelial (MCF-10a) cell lines.…”