Search

In this work, Pt(II) complexes of previously synthesized steroidal thiosemicarbazones were synthesized and characterized. The ligands and their metal complexes were studied by analytical and spectroscopic data (elemental analysis, IR, 1D-NMR and 2D-NMR, HSQC, HMBC, NOESY, COSY), the analysis of which enabled complete 1H and 13C assignments of each compound including E and Z isomers. All the synthesized ligands and complexes were screened for their cytotoxic and antimicrobial activity. The results demonstrate that the new steroidal thiosemicarbazone complexes were significantly less cytotoxic than the corresponding steroidal thiosemicarbazones. In addition, complexes showed lower antimicrobial activity than the standard drugs, similar to the activity of the starting thiosemicarbazones.

Fourteen mono- and bis-carbohydrazone ligands have been synthesized and characterized. Antioxidant activity of the substances was investigated together with possible (E)/(Z) isomerization, and explained on the most active antioxidant compound 4 in various dimethyl sulphoxide–water mixtures. The addition of water to the system was involved in the formation of hydrated molecules which was confirmed in NMR after the addition of D2O. The ligands were tested in vitro against Gram-positive and Gram-negative bacteria and fungi, and their activity was discussed in relation to the structure of investigated carbohydrazone. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172013]

The interactions of nine amino acid derivatives of tert-butylquinone with biomacromolecules were studied. SDS electrophoresis and mass spectrometry confirmed the absence of modifications of lysozyme by any of the synthesized compounds. Spectrophotometric studies demonstrated hyperchromism, i.e. existence of interactions between the quinones and CT-DNA. Determination of binding constant by absorption titration indicates weak interactions between quinone derivatives and CT-DNA. The quenching of fluorescence of intercalator ethidium bromide from EB-CT-DNA system and of minor groove binder Hoechst 33258 from H-CT-DNA system by the synthesized derivatives indicates interactions of compounds and CT-DNA. CD spectra demonstrate non-intercalative binding mode of quinone derivaties to CT-DNA. Molecular docking results confirm binding to the minor groove. Electrophoretic pattern showed no cleavage of pUC19 plasmid in the presence of any of the synthesized compounds. The ability of the derivatives to scavenge radicals was confirmed by DPPH test. All the presented results suggest that the DNA minor groove binding is the principal mechanism of action of the examined amino acid derivatives. [Projekat Ministarstva nauke Republike Srbije, br. 172055]

A series of sixteen novel substituted piperidines and (2-methoxyphenyl)piperazines were synthesized, starting from the key intermediates 1-(2-methoxyphenyl)-4-(piperidin-4-yl)piperazine and 1-(2-methoxyphenyl)-4-(piperidin-4-ylmethyl)piperazine. Biological evaluation of the synthesized compounds was pointed out for seven compounds, of which 1-(2-methoxyphenyl)-4-{[1-(2-nitrobenzyl)piperidin-4-yl]methyl}piperazine had the highest affinity for the dopamine D2 receptor. For all seven selected compounds docking analysis was performed in order to establish their structure-to-activity relationship. [Projekat Ministarstva nauke Republike Srbije, br. 172032]

Series of eight novel 5-substituted derivatives of benzimidazole were synthesized by condensation of corresponding diamine with ethyl-4-[4-(2-chlorophenyl)piperazin-1-yl] butanoate in refluxing 4N hydrochloric acid. In vitro antibacterial activity against ten strains namely, Bacillus subtilis, Clostridium sporogenes, Streptosporangium longisporum, Micrococcus flavus, Sarcina lutea, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis and Proteus vulgaris and antifungal activity against two fungal strains namely, Candida albicans and Saccharomyces cerevisiae, were evaluated. Of all the compounds screened for activity 2-{3-[4-(2-chlorophenyl)piperazin-1-yl]propyl}-5-iodo-1H-benzimidazole and 2-{3-[4-(2-chlorophenyl)piperazin-1-yl]propyl}-5-methyl-1H-benzimidazole were associated with higher antifungal activity than commercial drugs. [Projekat Ministarstva nauke Republike Srbije, br. 172032]

• The synthesis of new steroidal mono- and bis(semicarbazones) was performed. • The new carbazate esters were obtained. • The structures were determined by IR, NMR, HRMS and elemental analysis. • The antimicrobial and cytotoxic activities of the compounds were tested. • The replacement of C S with C O in steroidal hydrazone decrease biological activity. Eleven new steroidal mono- and bis(semicarbazones) 2a – e, 4d and 3a – e have been prepared starting from various 3-oxo-α,β-unsaturated steroids. Mono-semicarbazones 2a – e were further subjected to ethyl chloroacetate in boiling absolute ethanol but, instead of expected intramolecular cyclocondensation reaction products, the new carbazate esters 5a - e were obtained. The structures of all synthesized compounds and identification of each E / Z isomer were deduced by elemental analysis, HRMS, NMR, and IR spectroscopy. Preliminary screening for the cytotoxic activity in vitro of the new compounds has been conducted against three cancer cell lines, K562, Jurkat and HeLa cells. HeLa cells were the most sensitive while K562 cells were the least sensitive to the cytotoxic action of the novel steroid derivatives. Compounds 2e , 3c and 5e were found to have the best but still moderate cytotoxic effects. All tested compounds showed very weak antimicrobial activities. These results demonstrate that the replacement of thioxo group with carbonyl group in steroidal hydrazone derivatives resulted in decrease in their biological activity. [ABSTRACT FROM AUTHOR]

Screens of antioxidant activity (AA) of various natural products have been a focus of the research community worldwide. This work aimed to differentiate selected samples of Merlot wines originated from Montenegro, with regard to phenolic profile and antioxidant capacity studied by survival rate, total sulfhydryl groups and activities of glutathione peroxidase (GPx), glutathione reductase and catalase in H2O2–stressed Saccharomyces cerevisiae cells. In this study, DPPH assay was also performed. Higher total phenolic content leads to an enhanced AA under both conditions. The same trend was observed for catechin and gallic acid, the most abundant phenolics in the examined wine samples. Finally, the findings of an Artificial Neural Network (ANN) model were in a good agreement (r2 = 0.978) with the experimental data. All tested samples exhibited a protective effect in H2O2–stressed yeast cells. Pre-treatment with examined wines increased survival in H2O2–stressed cells and shifted antioxidative defense towards GPx–mediated defense. Finally, sensitivity analysis of obtained ANN model highlights the complexity of the impact that variations in the concentrations of specific phenolic components have on the antioxidant defense system. [ABSTRACT FROM AUTHOR]

The synthesis and cytotoxic activities determination of new steroidal mono- and bis(thiazolidin-4-ones) 4a – f and 5a – f have been performed. Their anticancer action was also evaluated in comparison to previously synthesized and reported corresponding steroidal thiosemicarbazones. All compounds were obtained as stereoisomeric mixtures with different configuration ( E or Z ) in the hydrazone moiety at the C-3 position. After several consecutive crystallizations diastereomerically pure major ( E )-isomers of mono-thiazolidin-4-ones were isolated. The structure and stereochemistry of 2,4-thiazolidinedione,2-[(17-oxoandrost-4-en-3-ylidene)hydrazone] were confirmed by X-ray analysis. A pathway for the formation of thiazolidin-4-one ring was proposed. The steroid thiazolidinone derivatives examined in this study exerted selective concentration-dependent cytotoxic activities on six tested malignant cell lines. Ten out of twelve examined compounds exhibited strong cytotoxic effects on K562 cells (IC 50 values from 8.5 μM to 14.9 μM), eight on HeLa cells (IC 50 values ranging from 8.9 μM to 15.1 μM) while against MDA-MB-361 cells six compouds exerted similar or even higher cytotoxic action (IC 50 values from 12.7 μM to 25.6 μM) than cisplatin (21.5 μM) which served as a positive control. Eight of these ten compounds showed high selectivity in the cytotoxic action against HeLa and K562 cancer cell lines when compared with normal human fibroblasts MRC-5 and normal human PBMC. The study of mechanisms of the anticancer activity of the two selected compounds, mono- and bis(thiazolidin-4-one) derivatives of 19-norandrost-4-ene-3,17-dione 4a and 5a, revealed that both of these compounds induced apoptosis in HeLa cells through extrinsic and intrinsic signalling pathways. Treatment of EA.hy926 cells with sub-toxic concentrations of these compounds led to the inhibition of cell connecting and sprouting, and tube formation. The synthesized compounds exhibited poor antioxidant activity. [ABSTRACT FROM AUTHOR]

The in vitro cytotoxic activity of previously synthesized steroid dimers with different spacer group (sulfide, trithiolane ring or phosphorotrithioate) and the substituent at C-17 position was tested for their possible effects against following human tumor cell lines: cervical adenocarcinoma (HeLa), chronic myelogenous leukemia (K562) and two human breast cancer cell lines (MDA-MB-361 and MDA-MB-453). These compounds, applied at micromolar concentrations, exhibited cytotoxic activity of different intensity (compared with cisplatin as a control), modality and selectivity in these malignant cell lines. The best activity against all four cell cancer lines was exhibited by dimer-sulfides. All screened compounds exerted concentration-dependent cytotoxic activity against leukemia K562 cells. The compounds which exerted the most pronounced cytotoxic action exhibited notably higher cytotoxic activities against K562, HeLa and MDA-MB-453 cells in comparison to resting and PHA-stimulated PBMC, pointing to a significant selectivity in their antitumor actions. Examination of the mechanisms of cytotoxicity on leukemia K562 cells revealed pro-apoptotic action of each of the investigated compounds applied at concentrations 2IC 50. The most prominent pro-apoptotic action was exhibited by dimer-sulfide of cholest-4-en-3-one. Furthermore, almost all of the tested compounds at IC 50 concentrations induced G1 phase cell cycle arrest in K562 cells. Antimicrobial activity against Gram-positive, Gram-negative bacteria and fungal cells, and toxicity to brine shrimp Artemia salina , were evaluated. There was no antibacterial activity. The best antifungal activity was exhibited against Saccharomyces cerevisiae by dimers linked with trithiolane ring, indicating a selective activity of investigated compounds. [ABSTRACT FROM AUTHOR]