Search

The treatment of N-Phenylmorpholine-4-carbothioamide (HPMCT) with bivalent metal ions in a 2:1 mol ratio without a base present affords [MCl2(κ1S-HPMCT)2] {M = Cu(1), Pd(2), Pt(3), and Hg(4)} in a good yield. Furthermore, the reaction of two equivalents of HPMCT and one equivalent of bivalent metal ions in the presence of Et3N has afforded [M(κ2S,N-PMCT)2] {M = Ni(5), Cu(6), Pd(7), Pt(8), Zn(9), Cd(10), and Hg(11)}. Infrared, 1H, 13C Nuclear Magnetic Resonance molar conductivity, and elemental analysis were used to characterize the synthesized complexes. The results suggest that HPMCT is bonded as monodentate via an S atom in Complexes (1–4), whereas linkage as a bidentate chelating ligand via S and N atoms gives two chelate rings. Moreover, the synthesized ligand and the complexes were screened for antibacterial activity, which displayed that the very best antibacterial activities for Complexes (1), (6), and (3). In addition, the cytotoxic activity of the HPMCT ligand, [PdCl2(HPMCT)2] (2), and [PtCl2(HPMCT)2] (3) were screened on breast cancer cell lines (MCF-7), and Complex (3) reveals the most promising activity with an IC50 value 12.72 ± 0.4 μM. Using the B3LYP method and 6-311++G(d,p) basis sets for the ligand and the SDD basis set for the central metal, the synthesized complexes utilizing the prepared ligand were optimized. Various quantum parameters such as hardness, electron affinity, dipole moment, vibrational frequencies, and ionization energy for the ligand and its complexes have been calculated. In general, a favorable agreement was found between the experimental results and the obtained theoretical results.

A series of metal (II) complexes of N‐cyclohexyl amine dithiocarbamate ligand are synthesized and characterized by Fourier transform infrared, 1H, 13C NMR, mass spectroscopy, and elemental analysis. The surface structural pattern of the prepared complexes were investigated by scanning electron microscope and X‐ray diffraction techniques. The prepared complexes possessed crystalline characteristic with size average ranging from 16 to 30 nm. Moreover, the biological activity of the synthesized complexes were tested against Klebsiella pneumoniae, Escherichia coli, and Staphylococcus aureus. Among the prepared complexes, copper (II) complex displayed the highest activity. In addition, molecular docking study was performed against bacterial tyrosinase enzyme which showed good binding interactions and is in agreement with the experimental findings. Furthermore, the in silico toxicity studies reveal that the complexes are mostly non‐irritant with mild toxicity. Different quantum parameters including electron affinity, ionization energy, dipole moment, hardness and vibrational frequencies were calculated for the ligand and its complexes using Gaussian 09 program and B3LYP/SDD level of theory. [ABSTRACT FROM AUTHOR]

The treatment of N-Phenylmorpholine-4-carbothioamide (HPMCT) with bivalent metal ions in a 2:1 mol ratio without a base present affords [MCl2(κ1S-HPMCT)2] {M = Cu(1), Pd(2), Pt(3), and Hg(4)} in a good yield. Furthermore, the reaction of two equivalents of HPMCT and one equivalent of bivalent metal ions in the presence of Et3N has afforded [M(κ2S,N-PMCT)2] {M = Ni(5), Cu(6), Pd(7), Pt(8), Zn(9), Cd(10), and Hg(11)}. Infrared, 1H, 13C Nuclear Magnetic Resonance molar conductivity, and elemental analysis were used to characterize the synthesized complexes. The results suggest that HPMCT is bonded as monodentate via an S atom in Complexes (1–4), whereas linkage as a bidentate chelating ligand via S and N atoms gives two chelate rings. Moreover, the synthesized ligand and the complexes were screened for antibacterial activity, which displayed that the very best antibacterial activities for Complexes (1), (6), and (3). In addition, the cytotoxic activity of the HPMCT ligand, [PdCl2(HPMCT)2] (2), and [PtCl2(HPMCT)2] (3) were screened on breast cancer cell lines (MCF-7), and Complex (3) reveals the most promising activity with an IC50 value 12.72 ± 0.4 μM. Using the B3LYP method and 6-311++G(d,p) basis sets for the ligand and the SDD basis set for the central metal, the synthesized complexes utilizing the prepared ligand were optimized. Various quantum parameters such as hardness, electron affinity, dipole moment, vibrational frequencies, and ionization energy for the ligand and its complexes have been calculated. In general, a favorable agreement was found between the experimental results and the obtained theoretical results. [ABSTRACT FROM AUTHOR]

This paper explores a dual inhibition of main protease (Mpro) and nonstructural protein 10/nonstructural protein 16 (NSP16) methyltransferase complex as the key targets for COVID-19 therapy. These are based on the new Schiff-base ligand that was obtained from the condensation of (4-chloro-3-methyl phenyl) hydrazine with 2-pyridine-carboxaldehyde and its novel Schiff-base metal complexes. These include Ni(II), Pd(II), Pt(II), Zn(II), and Hg(II). The newly synthesized compounds have been characterized using FT-IR, 1H NMR, 13C NMR, and elemental analysis. The results suggested that the Schiff-base ligand is coordinated as a bidentate ligand through the nitrogen atoms of the azomethine group and pyridyl ring. In addition, the biological activity of the prepared complexes was examined against Pseudomonas aeruginosa and Staphylococcus aureus, and the results showed that the Zn(II) complex has the highest activity compared with other compounds. The active sites were found by looking at the molecular electrostatic potential (MEP) maps of the above ligands and complexes. The activity of the compound and its Ni(II) and Zn(II) complexes against Mpro and NSP10/ NSP16 was investigated using a molecular docking approach. They showed excellent binding energies ranging from −5.9 to −7.2 kcal/mol and −5.8 to −7.2 for Mpro and NSP16, respectively. All conformers of the metal complexes were docked with the active site of the NSP16 receptor, showing a binding affinity of 100%. According to our knowledge, this was the first report of these metal complexes as dual inhibitors for Mpro and NSP16 of SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Ten transition metal dithiocarbamate (DTC)complexes of the type [M(κ2‐Et2DT)2] (1–5), and [M(κ2‐PyDT)2] (6–10) (where M = Co, Ni, Cu, Pd, and Pt; Et2DT = diethyl dithiocarbamate; PyDT = pyrrolidine dithiocarbamate) were synthesized and characterized by different methods. The dithiocarbamate acted as bidentate chelating ligands to afford a tetrahedral complexes with Co(II) ion and square planner with other transition metal ions. The dithiocarbamate complexes showed good activity against the pathogen bacteria species. The results showed the Pt‐dithiocarbamate complexes are more active against all the tested bacteria than the Pd‐dithiocarbamate complex. The dithiocarbamate complexes displayed the maximum inhibition zone against E. coli bacteria, whereas the lowest activity of the dithiocarbamate against Salmonella typhimurium bacteria. The cytotoxicity of the Pd(II) and Pt(II) complexes was screened against the MCF‐7 breast cancer cell line and the complexes showed moderate activity compared with the cis‐platin. The results indicated that the MCF7 cells treated with 500 μg\ml of ligands and Pd(II) and Pt(II) complexes after 24 hr exposure showed intercellular space and dead cells. Finally, molecular docking studies were carried out to examine the binding mode of the synthesized compounds against the proposed target; SARS COV2 RNA‐dependent RNA polymerase. [ABSTRACT FROM AUTHOR]

This paper reports the syntheses and spectral investigations of the new complexes [Pd(k1‐S‐ptt)2(k2‐dppmS2)] (1), [Pd(k1‐S‐ptt)2(k2‐dppp)] (2a), [Pd(k1‐N‐ptt)2(k2‐dppp)] (2b), [Pd(k1‐S‐ptt)2(k2‐dpppS2)] (3), [Pd(k1‐S‐ptt)2(k2‐dppb)] (4), [Pd(k1‐S‐ptt)2(k2‐dppf)] (5a) and [Pd(k1‐N‐ptt)2(k2‐dppf)] (5b), derived from 1‐phenyl‐5‐thiol‐1H‐tetrazole (Hptt) and diphosphine (dppmS2, dppp, dpppS2, dppb and dppf) as co‐ligand. The Hptt ligand acts as monodentate through the thiolato sulfur atom in complexes 1, 3 and 4. While in complexes 2 and 5, the Hptt ligand also acts as monodentate through the nitrogen of heterocyclic ring, or sulfur of thiol group after deprotonation, as two linkage isomers. Theoretical calculations on the all complexes were performed, isomers based on 2a, 2b and 5a, 5b reveal that each pair of isomers is isoenergetic. For the 2a and 2b complexes the energy difference was 19.92 kcal mol−1, while for the 5a and 5b complexes the difference was 11.78 kcal mol−1. These differences are relatively small and suggest that the linkage isomers may be in equilibrium in solution. The reasons for the adoption of these different coordination modes are not clear but steric factors are likely to be a major contributory factor. Further, in vitro anti‐bacterial activity and molecular docking analysis has been carried out to study the activity of the compound. [ABSTRACT FROM AUTHOR]