Synthesis, characterization, antitumor potential, BSA and DNA binding properties, and molecular docking study of some novel 3-hydroxy-3-pyrrolin-2-ones

BACKGROUND

In order to make progress in discovering the new agents for cancer treatment with improved properties and considering the fact that 3-hydroxy-3-pyrrolin-2-ones belong to a class of biologically active compounds, we tested series of eleven novels 1,5-diaryl-4-(2-thienylcarbonyl)-3-hydroxy-3-pyrrolin-2-ones for their antitumor potential.

METHODS

All novel compounds were characterized by spectral (IR, NMR, MS) and elemental analysis. All novel 3-hydroxy-3-pyrrolin-2-ones were screened for their cytotoxic activity on two cancer cell lines, SW480 and MDA-MB 231, and non-transformed fibroblasts (MRC-5).

RESULTS

Compounds B8, B9, and B10 showed high cytotoxicity on SW480 cells together with good selectivity towards MRC-5 cells. It is important to empathize that the degree of selectivity of B8 and B10 was high (SI = 5.54 and 12.09, respectively). Besides, we explored the mechanisms of cytotoxicity of novel derivatives, B8, B9, and B10. The assay showed that tested derivatives induce an apoptotic type of cell death in SW480 cells, with a minor percent of necrotic cells. Additionally, to better understand the suitability of the compounds for potential use as anticancer medicaments, we studied their interactions with biomacromolecules (DNA or BSA). The results indicated that the tested compounds have a great affinity to displace EB from the EB-DNA complex through intercalation. Also, DNA and BSA molecular docking study was performed to predict the binding mode and the interaction region of the compounds.

CONCLUSION

Achieved results indicate that our compounds have the potential to become candidates for use as medicaments.

Synthesis, Anticancer Evaluation and Synergistic Effects with cisplatin of Novel Palladium Complexes: DNA, BSA Interactions and Molecular Docking Study

BACKGROUND

In order to discover new agents for chemotherapy with improved properties compared to the existing agents and bearing in mind the fact that some Pd complexes possess better antitumor activity and exhibit less kidney toxicity compared to cisplatin, a series of novel square-planar palladium(II) complexes [Pd (L)2] (3a-f) with O,O bidentate ligands [L = ethyl 2- hydroxy-alkyl(aryl)-4-oxo-2-butenoate] were synthesized.

METHODS

All complexes were characterized by spectral (UV-Vis, IR, NMR, ESI-MS) and X-ray analysis and examined for their cytotoxic effect on human cancer cell lines HeLa and MDA-MB 231 and normal fibroblasts (MRC-5). Fluorescence spectroscopic method was used for investigations of the interactions between CT-DNA or bovine serum albumin (BSA) and complex 3c. Viscosity measurements and molecular docking study were performed to confirm the mode of interactions between DNA and BSA and complex 3c.

RESULTS

Complexes that showed the best results, 3c, 3d, and 3e, were placed under further investigations. Selected complexes induced apoptosis and cell cycle arrest in HeLa and MDA-MB 231 cells. Low concentrations of 3c and 3e showed strong to moderate synergism with low concentrations of cisplatin. The interaction of 3d with cisplatin was antagonistic in all used concentrations, but low IC50 value indicates its usefulness as a single cytotoxic agent. It was also noted that the change of viscosity is more pronounced in DNA solution after addition of complex 3c.

CONCLUSION

Obtained results indicate that the novel palladium(II) complexes have the potential to become candidates for treatment in anticancer therapy.

Synthesis, Characterization, Antioxidant Activity of β-diketonates, and Effects of Coordination to Copper(II) Ion on their Activity: DNA, BSA Interactions and Molecular Docking Study

BACKGROUND

In order to make some progress in discovering the more effective way to eliminate ROS which cause the oxidative stress in organism in humans and bearing in mind the fact that ethyl-2-hydroxy-4-aryl(alkyl)-4-oxo-2-butenoates (β-diketonates) belong to a class of biologically active compounds, series of β-diketonates were synthesized, characterized, and tested to evaluate there antioxidant activity. Further, to investigate how coordination to copper(II) ion affects the activity of β-diketonates, appropriate complexes were synthesized and characterized.

METHODS

All complexes were characterized by UV-Vis, IR, and EPR spectroscopy, MS spectrometry, and elemental analysis. Fluorescence spectroscopic method was used for investigations of the interactions between biomacromolecules (DNA or BSA) and compound 2E. Viscosity measurements and molecular docking study were performed to confirm the mode of interactions between DNA and BSA and compound 2E.

RESULTS

Scavenging activity on DPPH radical revealed that compounds 2A, 2B, and 2E possess largest free radical scavenging, comparable to standard while results of superoxide anion scavenging activities of tested samples showed that maximum scavenging activity (IC₅₀=168.92 μg/mL) was found for 2E, very similar to standard ascorbic acid, followed by 2B and 2G. Results of the interactions between biomacromolecules and 2E indicated that 2E has the affinity to displace EB from the EB-DNA complex through intercalation [K_sv = (3.7 ± 0.1) × 10³ M^-1], while K_a value obtained via titration of BSA with 2E [K_a = (4.2 ± 0.2) × 10⁵ M^-1], support the fact that the significant amount of the drug could be transported and distributed through the cells.

CONCLUSION

All β-diketonates exhibited better scavenging activities than their corresponding copper complexes. Among all the tested compounds, 2E gave the highest reducing power, even higher than standard ascorbic acid, while reducing power for compounds 2A and 2B was also good but lower than standard. DNA and BSA binding study for 2E showed that this compound has the potential to be used as medicament.

Synthesis, characterization, anticancer evaluation and mechanisms of cytotoxic activity of novel 3-hydroxy-3-pyrrolin-2-ones bearing thenoyl fragment: DNA, BSA interactions and molecular docking study

In order to make a progress in discovering a new agents for chemotherapy with improved properties and bearing in mind the fact that substituted 3-hydroxy-3-pyrrolin-2-ones belong to a class of biologically active compounds, series of novel 1,5-diaryl-4-(2-thienylcarbonyl)-3-hydroxy-3-pyrrolin-2-ones were synthesized and characterized by spectral (UV-Vis, IR, NMR, ESI-MS), X-ray and elemental analysis. All compounds were examined for their cytotoxic effect on human cancer cell lines HeLa and MDA-MB 231 and normal fibroblasts (MRC-5). Four compounds, 3-hydroxy-1-(p-tolyl)-4-(2-thienylcarbonyl)-5-(4-chlorophenyl)-2,5-dihydro-1H-pyrrol-2-one (D10), 3-hydroxy-1-(3-nitrophenyl)-4-(2-thienylcarbonyl)-5-(4-(benzyloxy)phenyl)-2,5-dihydro-1H-pyrrol-2-one (D13), 3-hydroxy-1-(4-nitrophenyl)-4-(2-thienylcarbonyl)-5-(4-(benzyloxy)phenyl)-2,5-dihydro-1H-pyrrol-2-one (D14), and 3-hydroxy-1-(4-chlorophenyl)-4-(2-thienylcarbonyl)-5-(4-(benzyloxy)phenyl)-2,5-dihydro-1H-pyrrol-2-one (D15), that showed the highest cytotoxicity against malignant cells and the best selectivity towards normal cells were selected for further experiments. Results obtained by investigating mechanisms of cytotoxic activity suggest that selected 3-hydroxy-3-pyrrolin-2-one derivatives in HeLa cells induce apoptosis that is associated with S phase arrest (D13, D15, and D10) or unrelated to cell cycle distribution (D14). Additionally, to better understand their suitability for potential use as anticancer medicaments we studied the interactions between biomacromolecules (DNA or BSA) and D13 and D15. The results indicated that D13 and D15 have great affinity to displace EB from the EB-DNA complex through intercalation [K_sv = (3.7 ± 0.1) and (3.4 ± 0.1) × 10³ M^-1, respectively], an intercalative mode also confirmed through viscosity measurements. K_a values, obtained as result of fluorescence titration of BSA with D13 and D15 [K_a = (4.2 ± 0.2) and (2.6 ± 0.2) × 10⁵ M, respectively], support the fact that a significant amount of the tested compounds could be transported and distributed through the cells. In addition, by DNA and BSA molecular docking study for D13, D14 and D15 is determined and predicted the binding mode and the interaction region.

Investigations into the bovine serum albumin binding and fluorescence properties of Tb (III) complex of a novel 8-hydroxyquinoline ligand

A novel ligand, 2-methyl-6-(8-quinolinyl)-dicarboxylate pyridine (L), and its corresponding Tb (III) complex, Na4Tb(L)2Cl4·3H2O, were successfully prepared and characterized. The luminescence spectra showed that the ligand L was an efficient sensitizer for Tb (III) luminescence. The interaction of the complex with bovine serum albumin (BSA) was investigated through fluorescence spectroscopy under physiological conditions. The Stern-Volmer analysis indicated that the fluorescence quenching was resulted from static mechanism. The binding sites (n) approximated 1.0 and this meant that interaction of Na4Tb(L)2Cl4·3H2O with BSA had single binding site. The results showed van der Waals interactions and hydrogen bonds played major roles in the binding reaction. Furthermore, circular dichroism (CD) spectra indicated that the conformation of BSA was changed.