Synthesis and Anticancer Properties of Silver(I) Complexes Containing 2,6-Bis(substituted)pyridine Derivatives

Several new 2,6-bis(substituted)pyridine ligands and 2,6-bis(substituted)pyridine Ag(I) nitrate complexes were synthesized and characterized spectroscopically. The newly synthesized ligands include pyridine-2,6-bis(3-oxopropanenitrile) (1), pyridine-2,6-bis(2-cyano-N-phenyl-3-oxopropanethioamide) (2), and pyridine-2,6-bis((E)-2-(2-phenylhydrazono)-3-oxopropanenitrile) (3). The newly synthesized ligands and silver(I) complexes were evaluated for their in vitro anticancer activity against four human cancer cell lines including hepatocellular carcinoma (HePG2), lung adenocarcinoma (A549), colon carcinoma (HT29), and breast adenocarcinoma (MCF7). Most of the newly synthesized silver(I) complexes exhibited better activity than the ligands, and the results have been compared with doxorubicin as a reference drug

Addition of N-aryl imines to alkyne(pentacarbonyl)chromium and tungsten : a novel route to alkenyl(amino)carbene complexes

Photolysis of [M(CO)6] in CH2Cl2 gives [(CO)5M(CH2Cl2)] (M=Cr, W). Replacement of CH2Cl2 by arylacetylene, HC=CC6H4R-p (R=Me, H, Br), produces the thermolabile arylacetylene complexes [(CO)5M(HC¡ÔCC6H4R-p)]. Addition of N-phenyl benzylideneimines, PhN=C(C6H4R'-p)H (R'=Me, H, Cl), to solutions of these alkyne complexes affords alkenyl( amino)carbene complexes, [(CO)5M=C(NPhH)C(C6H4R-p)=C(C6H4R'-p)H], and 2-azetidin-1-ylidene complexes, [(CO)5M=C-NPh-C(C6H4R'-p)H-C(C6H4R-p)H]. The formation of the alkenyl(amino)carbene complexes is favored. The ratio alkenyl(amino)carbene:2-azetidin-1-ylidene complex is 2.5¨C3 for M=W and 6.5¨C8 for M=Cr. Both types of complexes are obtained as mixtures of isomers. The 2-azetidin-1-ylidene complexes are very likely formed by cycloaddition of the imines to the C=C bond of vinylidene complexes resulting from tautomerization of the alkyne complexes. The cycloaddition is highly stereoselective. Predominantly, the syn isomer is obtained (syn/anti>9). In contrast, the alkenyl(amino)carbene complexes are presumably derived from the alkyne complexes via cycloaddition of the imines to the coordinated alkyne and subsequent 1,2-hydrogen shift and ring opening. Preferentially, the E isomers (where both aryl substituents are cis with respect to the C=C bond) are produced. The structure of the major isomer of the alkenyl(amino)carbene complex [(CO)5W=C(NPhH)C(C6H4Me-p) =C(Ph)H] has been established by X-ray structural analysis

Coordination versatility of N2O4 polydentate hydrazonic ligand in Zn(II), Cu(II), Ni(II), Co(II), Mn(II) and Pd(II) complexes and antimicrobial evaluation

New polydentate hydrazone ligand, was synthesized by the condensation of 1,5-dimethyl-3-oxo-2-phenylpyrazole-4-carbaldehyde with adipodihydrazide. The structure of the synthesized ligand, Nâ²1,Nâ²6-bis((1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl) methylene) adipohydrazide was elucidated by various analytical and spectroscopic techniques. The reactions of the ligand with zinc(II), copper(II), nickel(II), cobalt(II), manganese(II) and palladium(II) salts afforded homobinuclear metal complexes. Characterization and structure elucidation of the prepared complexes were achieved using different analytical and spectroscopic techniques. The analyses data indicated that this ligand behaved as N2O4 dibasic hexadentate ligand bonded covalency to the metal ions through the enolic carbonyl oxygen of hydrazide moiety and coordinated via carbonyl oxygen of antipyrine moiety and azomethine nitrogen atoms forming distorted octahedral geometry around the metal ions. The ESR spectra of copper(II) complexes (3) and (4) showed an axial symmetry with g||>gâ¥>ge, indicating distorted octahedral structure and presence of the unpaired electron in d(x2ây2) orbital. The microbicide studies of the ligand and its metal complexes (2), (3), (4), (5), (8), (11) and (13) showed that, all these complexes exhibit moderate to mild inhibitory effects on B. subtilis, E. coli while complexes (2), (3), (4) and (13) exhibit moderate to mild inhibitory effects on A. niger. Keywords: Hexadentate, Hydrazone, Antipyrine, ESR, Adipohydrazide, Microbicid

Synthesis, physicochemical studies and biological evaluation of unimetallic and heterobimetallic complexes of hexadentate dihydrazone ligands

A new coordination unimetallic and heterobimetallic complexes of hexadentate N2O4 donor dihydrazone ligands were prepared by the condensation of 4-formyl antipyrine with adipic dihydrazide and succinic dihydrazide. The ligands (1) and (11) and their complexes thoroughly characterized using various analytical, physical and spectroscopic techniques, which indicate a distorted octahedral geometry around the metal ions. The ESR spectra of solid copper(II) complexes (2–4) and (12–14) showed axial symmetry with g||>g⊥ > ge, indicating distorted octahedral structure and the presence of the unpaired electron in a d(x2−y2) orbital with significant covalent bond character. The antimicrobial activity results of the metal compounds (2–5), (7), (10), (12–15) and (17) show that, all these complexes exhibit inhibitory moderate to mild effects towards Bacillus subtilis, Escherichia coli and Aspergillus niger

Synthesis, anticancer activity and molecular docking study of Schiff base complexes containing thiazole moiety

AbstractA Schiff base ligand 1 was prepared from condensation of salicyaldehyde with 2-amino-4-phenyl-5-methyl thiazole. The ligand forms complexes with CoII, NiII, CuII, and ZnII in good yield. The synthesized compounds were characterized by elemental analysis, magnetic susceptibility, molar conductance, infrared spectra, 1H and 13C NMR, mass, electronic absorption and ESR spectroscopy. The anticancer activity of the synthesized compounds was studied against different human tumor cell lines: breast cancer MCF-7, liver cancer HepG2, lung carcinoma A549 and colorectal cancer HCT116 in comparison with the activity of doxorubicin as a reference drug. The study showed that ZnII complex showed potent inhibition against human TRK in the four cell lines (HepG2, MCF7, A549, HCT116) by the ratio 80, 70, 61 and 64% respectively as compared to the inhibition in the untreated cells. Moreover, the molecular docking into TRK (PDB: 1t46) was done for the optimization of the aforementioned compounds as potential TRK inhibitors