Gold(iii) complexes of 5-methyl-5-(pyridyl)-2,4-imidazolidenedione: synthesis, physicochemical, theoretical, antibacterial, and cytotoxicity investigation

Abstract

This work reports the synthesis and characterization of cytotoxic gold(III) complexes of a series of 5-methyl-5-(pyridyl)-2,4-imidazolidenedione ligands. Based on the elemental analysis and inductively coupled plasma-mass spectrometry (ICP-MS), the complexes have the general formula AuL1Cl 2 (1), [Au(L2) 2 Cl 2 ][AuCl 4 ] (2), and [Au(L3) 2 Cl 2 ][AuCl 4 ] (3) (L1, L2, and L3 = 5-methyl-5-(2,3, and 4-pyridyl)-2,4-imidazolidenedione, respectively). All the compounds were studied by means of IR, 1 H, 13 C NMR spectral analyses, molar conductivity, cyclic voltammetry, and DFT methods. The studies showed the complexes have square planar geometry, common for d 8 complexes, with the ligand molecule coordinated in an N-coordination bidentate (1) and monodentate (2 and 3) fashion to the metal center. DFT studies on different geometrical isomers suggested that in both the gas and solution phases, the trans isomers for 2 and 3 are more stable than the cis ones. The antibacterial activity and in vitro cytotoxicity of these compounds, as respectively assessed in six bacterial strains and two human tumor cell lines, have been investigated. The results showed the title complexes have the capacity to inhibit the metabolic growth of the investigated bacteria and tumor cells to different extents. The cytotoxicity profiles of the complexes against MCF-7 tumor cell lines are comparable to that of cisplatin (cis-diamminedichloroplatinum(II), DDP).

A palladium–phosphine catalytic system as an active and recycable precatalyst for Suzuki coupling in water

“…A single anodic peak (A L1 ) was observed on the reverse scan. This behavior is similar to that reported previously by Champness et al [37], Batchelor et al [38], Downard et al [39] and our group [40][41][42] in cyclic voltammetric studies of various types of Pd(II) complexes The cathodic peak C M1 at 1.05 V versus the Ag/AgCl reference electrode can be assigned to the formation of a Pd(0) center with a coordination number between 2 and 4 [or alternatively to an equilibrium mixture of several Pd(0) species] [39,[43][44][45]. There are some examples of stable Pd(0) complexes; particularly relevant is [Pd(L) 2 ] 0 (L = 1,2-bis(dimethylarsino)benzene), which is sufficiently stable to be isolated as a solid [46].…”

Pd(II) and Pd(IV) complexes with 5-methyl-5-(4-pyridyl)hydantoin: Synthesis, physicochemical, theoretical, and pharmacological investigation

“…In these cases, use of a ligand system that can stabilizes both Pd(III) and Pd(IV) 72 complexes promotes aerobic oxidation of organometallic Pd(II) precursors. 73 Continuing our research program on preparation of metal complexes with various derivatives 74 of 5-Methyl-5-(pyridyl)-2,4-imidazolidenedione with potential biological activity [19][20][21][22], in the 75 present work we describe the synthesis, spectroscopic, theoretical, and pharmacological aspects Mueller-Hinton broth (Merck) according to NCCLS [36]. The experiments were repeated at least 160 three to five times for each organism and data are presented as the mean ± SE of 3-5 samples.…”

New Rh(III) complexes of 5‐methyl‐5‐(pyridyl)‐2,4‐imidazolidenedione: Synthesis, X‐ray structure, electrochemical study and catalytic behaviour for hydrogenation of ketones

“…The formation of heavy metal complexes with solvent molecules is natural for solvents such as DMSO, which behave as strong ligands (L) and form M─L bonds. Recently, the synthesis and characterization of a mononuclear Pt(II) complex containing one DMSO as ligand were reported by our group . As evident from the literature, the trans isomers 2b and 3b are more stable than the cis ones.…”

“…The profound interest in various hydantoin derivatives stems from the well‐established medical applications of some of them as antiepileptic drugs . The coordination behaviour of these ligands towards several metal ions shows that they can coordinate to metal ions in three modes as depicted in Scheme : monodentate, N – N bidentate and O – O bidentate modes …”

“…Recently, our group reported the synthesis and biological application of Pd(II), Pt(II) and Au(III) complexes containing hydantoin ligands. It was shown that the reaction of hydantoin ligand 5‐methyl‐5‐(2‐pyridyl)‐2,4‐imidazolidenedione (HL1) with Pd(II), Pt(II) and Au(III) gives five‐membered metallacycle complexes.…”