Design, synthesis, and molecular docking study of novel cinnoline derivatives as potential inhibitors of tubulin polymerization

The preparation of a novel 4-methylbenzo[h] cinnolines entity via a three-step synthetic protocol is described. Cyclization of the naphthylamidrazones, in the presence of polyphosphoric acid (PPA), furnishes the respective target benzo[h]cinnolines directly. This one-pot synthesis involves intramolecular Friedel-Crafts acylation followed by instant elimination under heating conditions. It is noteworthy that the yield of the product from this step decreases dramatically if the heating is extended beyond 3 h. The target novel cinnolone derivatives were identified by mass spectrometry and their structures elucidated by spectroscopic techniques. Subsequently, molecular docking was performed to shed light on the putative binding mode of the newly synthesized cinnolines. The docking results indicate that these derivatives are potential inhibitors of tubulin polymerization and the best interaction was achieved with a computational ki = 0.5 nM and posed correctly over the lexibulin.

Piperazine-based Semicarbazone Derivatives as Potent Urease Inhibitors: Design, Synthesis, and Bioactivity Screening

Background:

An enzyme called urease assists highly pathogenic bacteria in colonizing and maintaining themselves. Accordingly, inhibiting urease enzymes has been shown to be a promising strategy for preventing ureolytic bacterial infections.

Objective:

This study aimed to synthesize and evaluate the bioactivity of a series of semicarbazone derivatives.

Methods:

A series of piperazine-based semicarbazone derivatives 5a-o were synthesized and isolated, and their structures were elucidated by 1H-NMR and 13C-NMR spectroscopic techniques besides MS and elemental analysis. The urease inhibition activity of these compounds was evaluated using the standard urease enzyme inhibition kit. An MTT assay was performed on two different cell lines (NIH-3T3 and MCF-7) to investigate the cytotoxicity profile.

Results:

All semicarbazone 5a-o exhibited higher urease inhibition activity (3.95–6.62 μM) than the reference standards thiourea and hydroxyurea (IC50: 22 and 100 μM, respectively). Derivatives 5m and 5o exhibited the best activity with the IC50 values of 3.95 and 4.05 μM, respectively. Investigating the cytotoxicity profile of the target compound showed that all compounds 5a-o have IC50 values higher than 50 μM for both tested cell lines.

Conclusion:

The results showed that semicarbazone derivatives could be highly effective as urease inhibitors.

Novel 5-fluoro-6-(4-(2-fluorophenyl)piperazin-1-yl)-2-(4-(4-methylpiperazin-1-yl)phenyl)-1H-benzo[d]imidazole derivatives as promising urease inhibitors

Background:

Highly pathogenic bacteria colonize and maintain themselves with the aid of an enzyme called urease. Consequently, inhibiting urease enzymes can be a promising method for preventing ureolytic bacterial infections.

Objective:

Synthesis and bioactivity screening of a novel series of benzimidazole derivatives.

Methods:

Nine novel benzimidazole derivatives 10α-Ɣ were synthesized, isolated, and their structures were elucidated by 1H-NMR and IR spectroscopic techniques besides HRMS. The urease inhibition activity of these compounds was evaluated using the standard urease enzyme inhibition kit. An MTT assay was performed on NIH-3T3 cell line to investigate the cytotoxicity profile.

Results:

All benzimidazoles 10α-Ɣ exhibited higher urease inhibition activity (3.06–4.40 µM) than the reference standards thiourea and hydroxyurea (IC50: 22 and 100 µM, respectively). 10Ɣ-1 and 10α-1 exhibited the best activity with the IC50 values of 3.06 and 3.13 µM, respectively. Investigate of the cytotoxicity profile of the target compound, showed all 10α-Ɣ have IC50 values higher than 50 µM on tested cell line.

Conclusion:

The results showed that synthesized benzimidazole derivatives can be highly effective as urease inhibitors.

Novel benzimidazole derivatives; synthesis, bioactivity and molecular docking study as potent urease inhibitors

BACKGROUND

Benzimidazole derivatives are widely used to design and synthesize novel bioactive compounds. There are several approved benzimidazole-based drugs on the market.

OBJECTIVES

In this study, we aimed to design and synthesize a series of novel benzimidazole derivatives 8a-n that are urease inhibitors.

METHODS

All 8a-n were synthesized in a multistep. To determine the urease inhibitory effect of 8a-n, the urease inhibition kit was used. The cytotoxicity assay of 8a-n was determined using MTT method. Molecular modelling was determined using autodock software.

RESULTS

All 8a-n were synthesized in high yield, and their structures were determined using 1H-NMR, 13C-NMR, MS, and elemental analyses. In compared to thiourea and hydroxyurea as standards (IC50: 22 and 100 µM, respectively), all 8a-n had stronger urease inhibition activity (IC50: 3.36-10.81 µM). With an IC50 value of 3.36 µM, 8e had the best enzyme inhibitory activity. On two evaluated cell lines, the MTT cytotoxicity experiment revealed that all 8a-n have IC50 values greater than 50 µM. Finally, a docking investigation revealed a plausible way of interaction between the 8e and 8d and the enzyme's active site's key residues.

CONCLUSION

The synthesized benzimidazole derivatives exhibit high activity, suggesting that further research on this family of compounds would be beneficial to finding a potent urease inhibitor.

An approach to pharmacological targets of pyrrole family from a medicinal chemistry viewpoint

Pyrrole is one of the most widely used heterocycles in the pharmaceutical industry. Due to the importance of pyrrole structure in drug design and development, herein, we tried to conduct an extensive review of the bioactive pyrrole based compounds reported recently. The bioactivity of pyrrole derivatives varies, so in the review, we categorized them based on their direct pharmacologic targets. Therefore, readers are able to find the variety of biologic targets for pyrrole containing compounds easily. This review explains around seventy different biologic targets for pyrrole based derivatives, so, it is helpful for medicinal chemists in design and development novel bioactive compounds for different diseases. This review presents an extensive meaningful structure activity relationship for each reported structure as much as possible. The review focuses on papers published between 2018 and 2020.

NMR-based Drug Development and Improvement Against Malignant Melanoma - Implications for the MIA Protein Family

The Melanoma Inhibitory Activity (MIA) protein is strongly expressed and secreted by malignant melanoma cells and was shown to promote melanoma development and invasion. The MIA protein was the first extracellular protein shown to adopt an Src homology 3 (SH3) domain-like fold in solution that can bind to fibronectin type III domains. Together with MIA, the homologous proteins OTOR (or FDP), MIA-2, and TANGO (or MIA-3) constitute a protein family of non-cytosolic and - except for fulllength TANGO and TANGO1-like (TALI) - extracellular SH3-domain containing proteins. Members of this protein family modulate collagen maturation and export, cartilage development, cell attachment in the extracellular matrix, and melanoma metastasis. These proteins may thus serve as promising targets for drug development against malignant melanoma. For the last twenty years, NMR spectroscopy has become a powerful technique in medicinal chemistry. While traditional high throughput screenings only report on the activity or affinity of low molecular weight compounds, NMR spectroscopy does not only relate to the structure of those compounds with their activity, but it can also unravel structural information on the ligand binding site on the protein at atomic resolution. Based on the molecular details of the interaction between the ligand and its target protein, the binding affinities of initial fragment hits can be further improved more efficiently in order to generate lead structures that exhibit significant therapeutic effects. The NMR-based approach promises to greatly contribute to the quest for low molecular weight compounds that ultimately could yield drugs to treat skin-related diseases such as malignant melanoma more effectively.

The small GTPases Ras and Rheb studied by multidimensional NMR spectroscopy: structure and function

Ras GTPases are key players in cellular signalling because they act as binary switches. These states manifest through toggling between an active (GTP-loaded) and an inactive (GDP-loaded) form. The hydrolysis and replenishing of GTP is controlled by two additional protein classes: GAP (GTPase-activating)- and GEF (Guanine nucleotide exchange factors)-proteins. The complex interplay of the proteins is known as the GTPase-cycle. Several point mutations of the Ras protein deregulate this cycle. Mutations in Ras are associated with up to one-third of human cancers. The three isoforms of Ras (H, N, K) exhibit high sequence similarity and mainly differ in a region called HVR (hypervariable region). The HVR governs the differential action and cellular distribution of the three isoforms. Rheb is a Ras-like GTPase that is conserved from yeast to mammals. Rheb is mainly involved in activation of cell growth through stimulation of mTORC1 activity. In this review, we summarise multidimensional NMR studies on Rheb and Ras carried out to characterise their structure-function relationship and explain how the activity of these small GTPases can be modulated by low molecular weight compounds. These might help to design GTPase-selective antagonists for treatment of cancer and brain disease.

Design, Synthesis, and Cytotoxicity of 5-Fluoro-2-methyl-6-(4-aryl-piperazin-1-yl) Benzoxazoles

To design new compounds suitable as starting points for anticancer drug development, we have synthesized a novel series of benzoxazoles with pharmaceutically advantageous piperazine and fluorine moieties attached to them. The newly synthesized benzoxazoles and their corresponding precursors were evaluated for cytotoxicity on human A-549 lung carcinoma cells and non-cancer HepaRG hepatocyes. Some of these new benzoxazoles show potential anticancer activity, while two of the intermediates show lung cancer selective properties at low concentrations where healthy cells are unaffected, indicating a selectivity window for anticancer compounds.