Milan D. Joksović

Synthesis and antimicrobial activity of some new pyrazole derivatives containing a ferrocene unit.

A series of new imines and amines have been synthesized by condensation of 1H-3-ferrocenyl-1-phenylpyrazole-4-carboxaldehyde with the corresponding amines, followed by reduction with sodium borohydride. The synthesized compounds have been screened for their in vitro antimicrobial activity against 11 bacteria and three fungal/yeast strains, using disc diffusion and broth microdilution susceptibility assays. They have shown a wide range of activities, from completely inactive to the highly active compounds.

Synthesis, characterization, electrochemical studies and antitumor activity of some new chalcone analogues containing ferrocenyl pyrazole moiety

A series of new alpha,beta-unsaturated conjugated ketones containing ferrocenyl pyrazole unit were synthesized and fully characterized by IR and NMR spectroscopy. Electrochemical characterization of subject compounds was performed by means of cyclic voltametry. The in vitro cytotoxic activity of all the synthesized compounds was studied against cervix adenocarcinoma HeLa, melanoma Fem-x and myelogenous leukemia K562 cell lines by the MTT method. Derivative 1l containing 3-pyridyl moiety exhibited a better cytotoxic activity in the cell growth inhibition of K562 cell lines in comparison with cisplatin as a reference compound.

Synthesis, characterization and antitumor activity of polymeric copper(II) complexes with thiosemicarbazones of 3-methyl-5-oxo-1-phenyl-3-pyrazolin-4-carboxaldehyde and 5-oxo-3-phenyl-3-pyrazolin-4-carboxaldehyde.

New polymeric copper(II) complexes with two tridentate ONS thiosemicarbazone ligands containing substituted pyrazolone moiety were synthesized and characterized by means of spectroscopic, electrochemical and crystallographic techniques. While both ligands exist as different tautomers in the solid state and DMSO-d(6) solution, Cu(II) ion coordinates the ligands from the same tautomeric form with square-pyramidal geometry around each Cu atom. In the crystal structures, the copper(II) complex cation forms polymeric chains {[Cu(L)Cl](+)}(n) with a bridging chlorine atom. One of the complexes was found to have a significantly higher cytotoxic potential in comparison with cisplatin in inhibition of several cell lines (HL60, REH, C6, L929 and B16). The results obtained on the basis of flow cytometry indicated that apoptosis could be possible mechanism of cell death.

Novel anthraquinone based chalcone analogues containing an imine fragment: synthesis, cytotoxicity and anti-angiogenic activity.

A new class of imine derivatives of hybrid chalcone analogues containing anthraquinone scaffold was synthesized and evaluated for their in vitro cytotoxic activity against HeLa, LS174, and A549 cancer cells. The compound 5n with furan ring linked to imino group showed potent activity against all target cells with IC50 values ranging from 1.76 to 6.11μM. A mode of action study suggested that compounds induced changes typical for apoptosis in HeLa cells. The most active compounds inhibited tubulogenesis and 5h was found to exhibit a strong anti-angiogenic effect.

Anthraquinone–chalcone hybrids: Synthesis, preliminary antiproliferative evaluation and DNA-interaction studies

Novel anthraquinone based chalcone compounds were synthesized starting from 1-acetylanthraquinone in a Claisen-Schmidt reaction and evaluated for their anticancer potential against three human cancer cell lines. Compounds 4a, 4b and 4j showed promising activity in inhibition of HeLa cells with IC50 values ranging from 2.36 to 2.73 μM and low cytotoxicity against healthy MRC-5 cell lines. The effects that compounds produces on the cell cycle were investigated by flow cytometry. It was found that 4a, 4b and 4j cause the accumulation of cells in the S and G2/M phases in a dose-dependent manner and induce caspase-dependent apoptosis. All of three compounds exhibit calf thymus DNA-binding activity. The determined binding constants by absorption titrations (2.65 × 10(3) M(-1), 1.36 × 10(3) M(-1)and 2.51 × 10(3) M(-1) of 4a/CT-DNA, 4b/CT-DNA and 4j/CT-DNA, respectively) together with fluorescence displacement analysis designate 4a, 4b and 4j as strong minor groove binders, but no cleavage of plasmid DNA was observed.

Antiproliferative activity and QSAR studies of a series of new 4-aminomethylidene derivatives of some pyrazol-5-ones.

Twenty five 4-aminomethylidene derivatives obtained from 3-phenyl-2-pyrazolin-5-one and 1,3-diphenyl-2-pyrazolin-5-one were synthesized and tested for their antiproliferative activity against human breast cancer MDA-MB-361 and MDA-MB-453 cell lines. The compounds derived from 1,3-diphenyl-2-pyrazolin-5-one exhibited the most remarkable activity in the treatment of both cell lines. In vitro antiproliferative activities were accompanied by an important apoptotic fraction of both cell lines; also, compounds inhibited key endothelial cell functions implicated in invasion and angiogenesis. QSAR methods were performed in order to analyze the influence of structural features of the compounds investigated on the antiproliferative potential on MDA-MB-361 and MDA-MB-453 cancer cells. One-parameter heuristic analysis was performed and different whole molecule and fragmental descriptors were considered for rationalization of mechanism of interaction of these compounds with active place of hypothetical target included in tumorigenesis.

Square-planar copper(II) complexes with a novel tetradentate amido-carboxylate ligand. Crystal structure of [Co(H2O)6][Cu(mda)] · 2H2O

A novel O—N—N—O-type tetradentate ligand H4mda (H4mda = malamido-N,N′-diacetic acid) and the corresponding square-planar copper(II) complexes have been prepared and characterized. The mda4− ligand coordinates to the copper(II) ion via two pairs of deprotonated ligating atoms (two carboxylate oxygens and two deprotonated amide nitrogens) with in-plane square chelation. A four-coordinate, square-planar geometry has been established crystallographically for the [Co(H2O)6][Cu(mda)] · 2H2O complex. Structural data correlating the square-planar geometry of the [Cu(mda)]2− unit are discussed in relation to information obtained for similar complexes. The i.r., electronic, absorption and reflectance spectra of the complexes are analysed in comparison with related complexes of known geometries.

Synthesis, cytotoxic activity and DNA-interaction studies of novel anthraquinone-thiosemicarbazones with tautomerizable methylene group.

A series of novel anthraquinone-thiosemicarbazone derivatives in a tautomerizable keto-imine form was synthesized and tested for their in vitro cytotoxic activity against human cancer cells (HeLa, MDA-MB-361, MDA-MB-453, K562, A549) and human normal MRC-5 cells. Several compounds efficiently inhibited cancer cell growth at micromolar concentrations, especially against K562 and HeLa cells. As determined by flow cytometric analysis, anthraquinone-thiosemicarbazone caused significant increase in the number of sub-G1 phase of HeLa cells and apoptosis in a concentration-dependent manner. Also, inhibition of caspase-3, -8, and -9 with specific caspase inhibitors reduced the apoptosis mediated by the tested compounds in HeLa cells. All anthraquinone-thiosemicarbazones exhibit calf thymus DNA-binding activity, but no cleavage of plasmid DNA was observed.

Chemotaxonomy of Serbian Teucrium species inferred from essential oil chemical composition: the case of Teucrium scordium L. ssp. scordioides.

The volatile constituents of Teucrium scordium L. ssp. scordioides, T. polium, and T. montanum, obtained by hydrodistillation, were investigated by GC‐FID and GC/MS analyses. A total of 296 constituents were identified, representing 89.8–98.4% of the oil compositions. The oils of T. polium and T. montanum consisted mainly of sesquiterpenes (64.3 and 72.7%, resp.), with germacrene D (4; 31.0%) and δ‐cadinene (10; 8.1%) as the main constituents, respectively. In contrast, the monoterpene menthofuran (1; 11.9%) predominated in the oil of T. scordium ssp. scordioides, and this clearly distinguished this species from the other Teucrium taxa investigated up to date. The chemistry of the volatiles of eight Teucrium taxa from Serbia and Montenegro were compared using multivariate statistical analysis, and this provided chemotaxonomically important conclusions.

Synthesis, antitumor activity and QSAR studies of some 4-aminomethylidene derivatives of edaravone.

A series of aminomethylidene derivatives obtained from 4-formyledaravone were synthesized and characterized by IR, NMR and elemental analysis. All the compounds were screened for their antitumor activity. The compound containing 5-phenylpyrazole moiety (3q) exhibited remarkable antitumor activity in in vitro assays, especially against human breast cancer MDA-MB-361 and MDA-MB-453 cell lines. The most important whole-molecule descriptors for antitumor activity on MDA-MB-453 cells belong to the group of quantum-chemical descriptors.