Synthesis and anticancer activity of novel 3,4-diarylthiazol-2(3H)-ones (imines)

Tubulin inhibitors: pharmacophore modeling, virtual screening and molecular docking

AIM

To construct a quantitative pharmacophore model of tubulin inhibitors and to discovery new leads with potent antitumor activities.

METHODS

Ligand-based pharmacophore modeling was used to identify the chemical features responsible for inhibiting tubulin polymerization. A set of 26 training compounds was used to generate hypothetical pharmacophores using the HypoGen algorithm. The structures were further validated using the test set, Fischer randomization method, leave-one-out method and a decoy set, and the best model was chosen to screen the Specs database. Hit compounds were subjected to molecular docking study using a Molecular Operating Environment (MOE) software and to biological evaluation in vitro.

RESULTS

Hypo1 was demonstrated to be the best pharmacophore model that exhibited the highest correlation coefficient (0.9582), largest cost difference (70.905) and lowest RMSD value (0.6977). Hypo1 consisted of one hydrogen-bond acceptor, a hydrogen-bond donor, a hydrophobic feature, a ring aromatic feature and three excluded volumes. Hypo1 was validated with four different methods and had a goodness-of-hit score of 0.81. When Hypo1 was used in virtual screening of the Specs database, 952 drug-like compounds were revealed. After docking into the colchicine-binding site of tubulin, 5 drug-like compounds with the required interaction with the critical amino acid residues and the binding free energies < -4 kcal/mol were selected as representative leads. Compounds 1 and 3 exhibited inhibitory activity against MCF-7 human breast cancer cells in vitro.

CONCLUSION

Hypo1 is a quantitative pharmacophore model for tubulin inhibitors, which not only provides a better understanding of their interaction with tubulin, but also assists in discovering new potential leads with antitumor activities.

Practical organic solvent-free Cu(OAc)2/DMAP/TEMPO-catalyzed aldehyde and imine formation from alcohols under air atmosphere

A highly efficient and practical organic solvent-free Cu(OAc)₂/DMAP/TEMPO catalyst system for the selective aerobic oxidation of benzylic and allylic alcohols to aldehydes and phenones under an ambient air atmosphere was reported.

Synthesis, characterization and antimicrobial activity of certain novel aryl hydrazone pyrazoline-5-ones containing thiazole moiety

PURPOSE

The aim of this article is to synthesize, characterize and evaluate the antimicrobial activity of certain novel 3-methyl-5-oxo-4-(phenyl hydrazono)-4,5-dihydro-pyrazol-1-yl]-acetic acid N|-(4-substituted thiazol-2-yl)-hydrazides.

METHODS

The synthesized compounds were characterized by elemental analysis and IR, NMR and mass spectral data. The antimicrobial activity of novel compounds was evaluated by broth dilution method.

RESULTS

XVe, XVf and XVg have shown better antibacterial activity than other compounds of the series. XVa, XVc, XVd and XVe have shown better antifungal activity than the other compounds of the series.

CONCLUSION

All compounds were found to exhibit fair degree of antimicrobial activity.

Novel phenyl(thio)ureas bearing (thio)oxothiazoline group as potential BACE-1 inhibitors: synthesis and biological evaluation

We report the synthesis and the β-site amyloid precursor protein cleaving enzyme-1 inhibitory properties of novel phenyl(thio)ureas bearing 2-(thio)oxothiazoline derivatives. A library of analogues was prepared according to specific synthetic schemes and the inhibitory activity was monitored using a fluorescence resonance energy transfer assay. Several analogues show potent inhibitory activities ranging between 1 and 0.01 µM and the activity is related to the NH acidity of the (thio)urea motif. Our results illustrate once again the close relationship between molecular recognition, complexation of the active site in enzymatic system, and organocatalysis utilizing explicit hydrogen bonding.

Microwave-Assisted Synthesis of 1,3,4-Thiadiazole Schiff Base Derivatives

A rapid and efficient microwave-assisted synthesis method for the preparation of 1,3,4-thiadiazole Schiff base derivatives is described. These 1,3,4-thiadiazole Schiff bases (5a-h) were identified by IR, 1H NMR, elemental analyses. The target compounds were performed in a shorter reaction time compared with conventional heating methods.