Synthesis and structural characterizations of three carbonyl(α-diimine)hydrido(triphenylphosphine)ruthenium(II) complexes with derivatives of 1,10-phenanthroline.

Three new ruthenium(II) polypyridyl complexes containing α-diimine ligands, namely, carbonylhydrido(1,10-phenanthroline-κ2N,N)bis(triphenylphosphine-κP)ruthenium(II) hexafluorophosphate, [RuH(C12H8N2)(C18H15P)2(CO)]PF6, carbonylhydrido(2,9-dimethyl-1,10-phenanthroline-κ2N,N)bis(triphenylphosphine-κP)ruthenium(II) hexafluorophosphate, and carbonylhydrido(4,7-dimethyl-1,10-phenanthroline-κ2N,N)bis(triphenylphosphine-κP)ruthenium(II) hexafluorophosphate, both [RuH(C14H12N2)(C18H15P)2(CO)]PF6, were synthesized and characterized by spectroscopic and X-ray diffraction methods. In these complexes, the ruthenium(II) ion adopts a distorted octahedral geometry. There are no intermolecular hydrogen bonds in the crystal structures of the analysed complexes and Hirshfeld surface analysis showed that the H...H contacts constitute a high percentage, close to 50%, of the intermolecular interactions.

Structure-activity relationship and cytotoxicity of the new thiosemicarbazide derivatives and their Cu(II) complexes against prostate and melanoma cancer cells.

In this study, eighteen new ligands (B1-B18) containing a thiosemicarbazide core were synthesized and characterized in terms of physicochemical properties, molecular docking and in vitro biological activity. The structures of eleven ligands were investigated using X-Ray diffraction and Hirschfeld Surface analysis. To study the structure-activity relationship, the organic ligands contained pyridin-2-ylmethyl, pyridin-3-ylmethyl or pyridin-4-ylmethyl moieties and various substituents. Their pharmakokinetic profiles and molecular docking results suggest high potential as new drug candidates. The complexing ability of the selected organic ligands was also evaluated, yielding five new Cu(II) complexes (Cu(B1)Cl2, Cu(B4)Cl2, Cu(B10)Cl2, Cu(B17)Cl2, Cu(B18)Cl2). The obtained results suggest the formation of the polymeric structures. All organic ligands and Cu(II) complexes were tested for anticancer activity against prostate and melanoma cancer cells (PC-3, DU-145, LNCaP, A375, G-361, SK-MEL-28) and normal fibroblasts (BJ), as well as antimicrobial activity against six selected bateria strains. Among B1-B18 compounds, B3, B5, B9, B10, B12 and B14 exhibited cytotoxic activity. The studied Cu(II) complexes were in general more active, with Cu(B1)Cl2 exhibiting antincancer activity agains all three prostate cancer cells and Cu(B10)Cl2 reaching the IC50 value equal to 88 µM against G-361 melanoma cells. Several compounds also exhibited antimicrobial activity against gram-positive and gram-negative bacteria. It was found that the type of specific substituents, especially the presence of -chloro and -dichloro substituents had a greated impact on the cytotoxicity than the position of the nitrogen atom in the pyridylacetyl moiety.

N-Substituted 2-(Benzenosulfonyl)-1-Carbotioamide Derivatives Exert Antimicrobial and Cytotoxic Effects via Aldehyde Dehydrogenase Pathway: Synthesis, In Silico and In Vitro Studies.

A series of N-Substituted 2-(benzenosulfonyl)-1-carbotioamide derivatives (WZ1-WZ4) were synthesized and characterized using spectral methods. A comprehensive activity study was performed for each compound. All compounds were tested for antibacterial activity. Moreover, in silico studies were carried out to determine the anticancer potential of the designed WZ1-WZ4 ligands. Based on molecular docking, aldehyde dehydrogenase was selected as a molecular target. The obtained data were compared with experimental data in vitro tests. Novel hybrids of the thiosemicarbazide scaffold and sulfonyl groups may have promising anticancer activity via the aldehyde dehydrogenase pathway. The best candidate for further studies appears to be WZ2, due to its superior selectivity in comparison to the other tested compounds.

Novel phenoxyacetylthiosemicarbazide derivatives as novel ligands in cancer diseases.

Numerous epidemiological studies report an increased risk of developing prostate cancer in patients with melanoma and an increased risk of developing melanoma in patients with prostate cancer. Based on our previous studies demonstrating the high anticancer activity of thiosemicarbazides with a phenoxy moiety, we designed nineteen phenoxyacetylthiosemicarbazide derivatives and four of them acting as potential dual-ligands for both cancers. All of the compounds were characterized by their melting points and 1H, 13C NMR and IR spectra. For selected compounds, X-ray investigations were carried out to confirm the synthesis pathway, identify the tautomeric form and intra- and intermolecular interaction in the crystalline state. The conformational preferences and electronic structure of molecules were investigated by theoretical calculation method. Lipophilicity of compounds (log kw) was determined using isocratic reversed phase/high pressure liquid chromatography RP-18. For the obtained compounds, in vitro tests were carried out on four melanoma cell lines (A375, G-361, SK-MEL2, SK-MEL28), four prostate cancer cell lines (PC-3, DU-145, LNCaP, VcaP) and a normal human fibroblast cell line (BJ). The most active compounds turned out to be F6. Cell cycle analysis, apoptosis detection, CellROX staining and mitochondrial membrane potential analysis were performed for the most sensitive cancer cells treated with most active compounds. DSC analysis was additionally performed for selected compounds to determine their purity, compatibility, and thermal stability. The process of prooxidation was proposed as a potential mechanism of anticancer activity.

Polymer microspheres modified with pyrazole derivatives as potential agents in anticancer therapy - Preliminary studies.

The methods of fighting cancer are far from ideal, therefore it is necessary to search for innovative and effective drugs. In our work, we present pyrazole derivatives and their modifications with polymer microspheres as potential anticancer agents. Molecular and crystal structures of pyrazole derivatives were determined an X-ray analysis and characterized by theoretical calculations. Modifications of cross-linked polymer microspheres with pyrazole derivatives were made on the basis of divinylbenzene and glycidyl methacrylate. The in vitro antiproliferative activity of the pyrazole derivatives and their modified microspheres was assessed against a normal cell line, namely monkey epithelial renal cells (GMK) and cancer cell lines, such as human hepatocellular carcinoma cell line (HepG2), human breast adenocarcinoma cell line (MCF-7) as well as human lung adenocarcinoma cell line (A549), using the MTT assay. All the tested pyrazole derivatives and the polymer microspheres modified by them showed antiproliferative activity in vitro. Two of the modified substances showed the greatest ability to inhibit divisions of all cancer cells. In order to determine a potential target, molecular docking was performed. In silico studies carried out with the use of the human EphB1 receptor revealed that the analyzed compounds bound to the EphB1 binding site, and the compounds with the highest antiproliferative activity showed a better fit to the active site.

Potential Anticancer Agents against Melanoma Cells Based on an As-Synthesized Thiosemicarbazide Derivative.

In this paper, thiosemicarbazide derivatives were synthesized as potential anticancer agents. X-ray investigations for 1-(2,4-dichlorophenoxy)acetyl-4-(2-fluorophenyl) thiosemicarbazide, 1-(2,4-dichlorophenoxy)acetyl-4-(4-metylothiophenyl)thiosemicarbazide and 1-(2,4-di chlorophenoxy)acetyl-4-(4-iodophenyl)thiosemicarbazide were carried out in order to confirm the synthesis pathways, identify their tautomeric forms, analyze the conformational preferences of molecules, and identify intra- and intermolecular interactions in the crystalline state. TLC and RP-HPLC analyses were used to determine lipophilicity. The lipophilicity analysis revealed that the 4-substituted halogen derivatives of thiosemicarbazides showed greater lipophilicity compared with 2-substituted derivatives. The optimal range of lipophilicity for biologically active compounds logkw is between 4.14 and 4.78. However, as the analysis showed, it is not a decisive parameter. The cytotoxicity of the new compounds was evaluated against both the G-361 and BJ cell lines. Cytotoxicity analyses and cell-cycle and cell apoptosis assays were performed. The MTT test demonstrated that three compounds were cytotoxic to melanoma cells and not toxic to normal fibroblasts in the concentration range used. The cell cycle analysis showed that the compounds had no significant effect on the cell cycle inhibition. An extensive gene expression analysis additionally revealed that all compounds tested downregulated the expression of dihydroorotate dehydrogenase (DHODH). DHODH is a mitochondrial enzyme involved in the de novo synthesis of pyrimidines. Due to the rapid rate of cancer cell proliferation and the increased demand for nucleotide synthesis, it has become a potential therapeutic target.

Influence of Complexation of Thiosemicarbazone Derivatives with Cu (II) Ions on Their Antitumor Activity against Melanoma Cells.

A series of thiosemicarbazone derivatives was prepared and their anti-tumor activity in vitro was tested. The X-ray investigation performed for compounds T2, T3 and T5 confirmed the synthesis pathway and assumed molecular structures of analyzed thiosemicarbazones. The conformational preferences of the thiosemicarbazone system were characterized using theoretical calculations by AM1 method. Selected compounds were converted into complexes of Cu (II) ions. The effect of complexing on anti-tumor activity has been investigated. The copper(II) complexes, with Schiff bases T1, T10, T12, T13, and T16 have been synthesized and characterized by chemical and elemental analysis, FTIR spectroscopy and TGA method. Thermal properties of coordination compounds were studied using TG-DTG techniques under dry air atmosphere. G361, A375, and SK-MEL-28 human melanoma cells and BJ human normal fibroblast cells were treated with tested compounds and their cytotoxicity was evaluated with MTT test. The compounds with the most promising anti-tumour activity were then selected and their cytotoxicity was verified with cell cycle analysis and apoptosis/necrosis detection. Additionally, DNA damages in the form of a basic sites presence and the expression of oxidative stress and DNA damage response genes were evaluated. The obtained results indicate that complexation of thiosemicarbazone derivatives with Cu (II) ions improves their antitumor activity against melanoma cells. The observed cytotoxic effect is associated with DNA damage and G2/M phase of cell cycle arrest as well as disorders of the antioxidant enzymes expression.

1,2,4-Triazine Sulfonamides: Synthesis by Sulfenamide Intermediates, In Vitro Anticancer Screening, Structural Characterization, and Molecular Docking Study.

In this study, we synthesized novel sulfonamides with a 1,2,4-triazine moiety according to pharmacophore requirements for biological activity. All the synthesized compounds were tested in vitro to verify whether they exhibited anticancer activity against the human breast cancer cell lines MCF-7 and MDA-MB-231. Among them, two most active ones, having IC50 values of 50 and 42 µM, respectively, were found to show higher anticancer activity than chlorambucil used as the reference in the in vitro tests. In addition, two other compounds, which had IC50 values of 78 and 91 µM, respectively, exhibited a similar level of activity as chlorambucil. X-ray analysis carried out for two of the compounds confirmed their synthesis pathway as well as their assumed molecular structures. Furthermore, a conformational analysis was performed, and electronic parameters of molecules were characterized using theoretical calculations at AM1 and DFT level. Moreover, molecular docking revealed the mode of binding of the investigated 1,2,4-triazine sulfonamides with the human estrogen receptor alpha (ERα).

Synthesis, Structural Characterization, and Biological Activity of New Pyrazolo[4,3-e][1,2,4]triazine Acyclonucleosides.

A series of new pyrazolo[4,3-e][1,2,4]triazine acyclonucleosides 2-5 and 8 were prepared and evaluated for their anticancer activity against human cancer cell lines (MCF-7, K-562) and CDK2/E, as well as Abl protein kinases inhibitors. Lipophilicity of the compounds was determined using C-18 and immobilized artificial membrane (IAM) chromatography. In order to confirm the molecular structures and synthesis pathway of new acyclonucleosides, X-ray analysis was performed for model compound 3. Theoretical calculations at the DFT/B3LYP/6-311++G(d,p) level were used for the characterization of electronic structures of 1-8. The potential antiviral activity of acyclonucleosides 2-8 was tested in silico using molecular docking method.

Synthesis, In Vitro Screening and Docking Studies of New Thiosemicarbazide Derivatives as Antitubercular Agents.

A series of thiosemicarbazide derivatives was designed and synthesized by reaction of carboxylic acid hydrazide with isothiocyanates. The molecular structures of the investigated thiosemicarbazides were confirmed and characterized by spectroscopic analysis. The conformational preference of carbonylthiosemicarbazide chain and intra- and intermolecular interactions in the crystalline state were characterized using X-ray analysis. The antituberculosis activity of the target compounds were tested in vitro against four Mycobacterium strains: M. H37Ra, M. phlei, M. smegmatis, M. timereck. The most active compounds were those with 2-pyridine ring. They exhibited lower minimal inhibitory concentration (MIC) values in the range 7.81⁻31.25 µg/mL in comparison to the other isomers. Compound 5 had activity against M. smegmatis at a concentration of 7.81 µg/mL whereas compound 2 had activity against all tested strains at a concentration of 15.625 µg/mL. The molecular docking studies were performed for investigated compounds using the Mycobacterium tuberculosis glutamine synthetase MtGS as their molecular target.

Synthesis of unsymmetrical disulfanes bearing 1,2,4-triazine scaffold and their in vitro screening towards anti-breast cancer activity.

ABSTRACT: A new series of 1,2,4-triazine unsymmetrical disulfanes were prepared and evaluated as anticancer activity compounds against MCF-7 human breast cancer cells with some of them acting as low micromolar inhibitors. Evaluation of the cytotoxicity using an MTT assay, the inhibition of [3H]-thymidine incorporation into DNA demonstrated that these products exhibit cytotoxic effects on breast cancer cells in vitro. The most effective compounds with 59 and 60 µM compared to chlorambucil with 47 µM were disulfanes bearing methyl and methoxy substituent in an aromatic ring. Furthermore, all new 14 compounds were obtained with 22-74% yield via mild and efficient synthesis of the sulfur-sulfur bond formation from thiols and symmetrical disulfanes using 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ). The molecular structure of the newly obtained compounds was confirmed by X-ray analysis. The conformational preferences of disulfide system were characterized using theoretical calculations at DFT level and statistical distributions of C-S-S-C torsion angle values based on the Cambridge Structural Database (CSD). The DFT calculations and CSD searching show two preferential conformations for C-S-S-C torsion angle close to ± 90° and relatively large freedom of rotation on S-S bond in physiological conditions. The molecular docking studies were performed using the human estrogen receptor alpha (ERα) as molecular target to find possible binding orientation and intermolecular interactions of investigated disulfanes within the active site of ERα. The S…H-S and S…H-C hydrogen bonds between sulfur atoms of bisulfide bridge and S-H and C-H groups of Cys530 and Ala350 as protein residues play crucial role in interaction with estrogen receptor for the most anticancer active disulfane.

Synthesis, Structure and Antiproliferative Activity of New pyrazolo[4,3- e]triazolo[4,5-b][1,2,4]triazine Derivatives.

BACKGROUND: Triazoles and their fused derivatives are an important class of compounds that exhibit interesting biological properties, such as antiasthmatic, antimicrobial, antifungal, analgesic, antiallergic, antiinflammatory, herbicidal, plant growth regulative activity, and anti-HIV-1 activities. Moreover, anticancer activity of 1,2,4-triazole containing derivatives has been documented. Due to the fact a convenient approach toward polycyclic frameworks containing fused 1,2,4-triazoles was described. OBJECTIVE: The objective of this article is the synthesis of new pyrazolo[4,3-e]triazolo[4,5- b][1,2,4]triazine derivatives with potential antiproliferative activity. METHODS: Cancer cell proliferation was analysed by means of MTT assay after 96 h treatment. IC50 was calculated using computerized linear regression analysis of quantal log doseprobit functions, according to the method of Litchfield and Wilcoxon. X-ray data were collected on the Bruker SMART APEX II CCD diffractometer; The structure was solved by direct methods using SHELXS-2013 and refined by full-matrix least-squares with SHELXL-2014/7. All calculations were performed using WINGX version 2014.1 package. RESULTS: The series of pyrazolo[4,3-e]triazolo[4,5-b][1,2,4]triazine derivatives were synthesized. MTT assay revealed that the compounds inhibited cancer cells growth at concentrations below 10 µM. The tested compounds showed higher antiproliferative activity than popular cytostatics cisplatin (lung carcinoma) and 5-fluorouracil (colon adenocarcinoma). X-ray examinations showed that final products in the crystalline phase have a linear form. CONCLUSION: In the paper we have reported the synthesis and spectroscopic analysis of new condensed tricyclic derivatives of the pyrazolo[4,3-e]triazolo[4,5-b][1,2,4]triazine. MTT analysis revealed concentration-dependent decrease in lung A549 and colon LS180 cancer cells proliferation. In order to explain the molecular mechanisms involved in anticancer activity of pyrazolo[4,3- e]triazolo[4,5-b][1,2,4]triazine derivatives, our research will be continued.

Novel thiosemicarbazide derivatives with 4-nitrophenyl group as multi-target drugs: α-glucosidase inhibitors with antibacterial and antiproliferative activity.

A series of thiosemicarbazides with 4-nitrophenyl group was obtained in the reaction of carboxylic acid hydrazides with isothiocyanates. All compounds were checked for their antibacterial and antiproliferative activity. Our results have shown that derivatives 6-8 possessed antibacterial activity against S. aureus, S. epidermidis, S. mutans and S. sanguinis, moderate cytotoxicity and good therapeutic safety in vitro. Additionally, compounds 1 and 4 significantly inhibited A549, HepG2 and MCF-7 cell division. Moreover, PASS software indicated that newly obtained compounds are potential α-glucosidase inhibitors. This was confirmed by in vitro studies. To investigate the mode of interaction with the molecular target compounds were docked to glucose binding site of the enzyme and exhibited a similar binding mode as glucose.

Discovery of nitroaryl urea derivatives with antiproliferative properties.

A series of urea derivatives bearing nitroaryl moiety has been synthesized and assayed for their potential antiproliferative activities. Some of the tested compounds displayed activity in RK33 laryngeal cancer cells and TE671 rhabdomyosarcoma cells while being generally less toxic to healthy HSF human fibroblasts cells. One compound was demonstrated to be a moderate CDK2 inhibitor with IC50 = 14.3 µM. Its structure was solved by an X-ray crystallography and molecular modelling was performed to determine structure-activity relationship. Obtained compounds constitute novel structures and generally demonstrated greater cytotoxicity in comparison to cisplatin. This study offers new structural motifs with potential for further development.

Synthetic approaches for sulfur derivatives containing 1,2,4-triazine moiety: their activity for in vitro screening towards two human cancer cell lines.

A series of sulfur 1,2,4-triazine derivatives were prepared and evaluated as anticancer compounds for two human breast cancer cell lines (MCF-7, MDA-MB-231) with some of them acting as low micromolar inhibitors. Evaluation of the cytotoxicity using a 3-(4,5-dimethylthiazol-2-yl)-3,5-diphenyltetrazolium bromide (MTT) assay, the inhibition of [(3)H]thymidine incorporation into DNA, and collagen synthesis inhibition demonstrated that these products exhibit cytotoxic effects on these breast cancer cell lines in vitro. The most effective were disulfide and sulfenamide compounds with two valence sulfur atoms. A structure-activity relationship study was performed using X-ray analysis and theoretical calculations at an ab initio density functional theory (DFT) level.

New approaches to the synthesis of sildenafil analogues and their enzyme inhibitory activity.

In the search for new biologically active chemotypes, several sildenafil analogs were prepared and characterized. The presence of the pyrazolo[4,3-e][1,2,4]triazine core is thought to be of interest for the enzyme inhibitory activity of these compounds. The designed derivatives incorporating the sildenafil scaffold were assayed as carbonic anhydrase inhibitors, and for their cytotoxic activity against MCF-7 and K562 cell lines. The X-ray analysis of one of these model compounds was performed and its crystal structure is described/compared to that of sildenafil.

Structural and molecular docking studies of 4-benzyl-3-[(1-methylpyrrol- 2-yl)methyl]-4,5-dihydro-1H-1,2,4-triazol-5-one with anticancer activity.

The 1,2,4-triazoles are an important group of medicinal substances which exhibit a wide range of activity, such as analgesic, antibacterial, fungicidal, antinflammatory, antiviral and anticancer. As a part of our long-term study on 1,2,4- triazoles we synthesize 4-benzyl-3-[(1-methylpyrrol-2-yl)methyl]-4,5-dihydro-1H-1,2,4-triazol-5-one which is characterized with anticancer activity. Here, we present an exhaustive studies of its electronic and molecular structure, aimed to rationalize the observed pharmacological activity, supported by the molecular docking to the EGFR kinase domain ATP binding site. The structural studies include X-ray analysis, experimental and computed spectral analysis (1H and 13C NMR, IR) as well as conformational analysis and the frontal molecular orbitals (FMO) analysis. The results of molecular docking indicate that interaction of 4-benzyl-3-[(1-methylpyrrol-2-yl)methyl]-4,5-dihydro-1H-1,2,4-triazol-5-one with the EGFR kinase domain ATP binding site may be responsible for the observed anticancer activity of this 1,2,4-triazole derivative. Moreover, we find that formation of the respective ligand-protein complex is conditioned by the keto-enol tautomerism of the ligand, i.e. the energetic prevalence of the keto form.