Exploring the antitumor potential of novel quinoline derivatives via tubulin polymerization inhibition in breast cancer; design, synthesis and molecular docking

A series of quinoline derivatives was designed and synthesized as novel tubulin inhibitors targeting the colchicine binding site. All the rationalized compounds 3a-e, 4a-e, 5a-e, and 6a-e have been chosen for screening their cytotoxic activity against 60 cell lines by NCI. Compounds 3b, 3c, 4c, 5c and 6c demonstrated the most notable antitumor activity against almost all cell lines. Compound 4c emerged as the most potent compound as an antiproliferative agent. This compound was subsequently chosen for five-dose testing and it exhibited remarkable broad-spectrum efficacy with strong antitumor activity against several cell lines. Compound 4c significantly induced cell cycle arrest in MDA-MB-231 cells at G2 and M phases where the cell population increased dramatically to 22.84% compared to the untreated cells at 10.42%. It also increased the population in MDA-MB-231 cells at both early and late stages of apoptosis. Compound 4c can successfully inhibit tubulin polymerization with an IC50 value of 17 ± 0.3 μM. The β-tubulin mRNA levels were notably reduced in MDA-MB-231 cells treated with compound 4c which is similar to the effect observed with colchicine treatment. Docking studies revealed that compound 4c interacted well with crucial amino acids in the active site.

Design, synthesis and mechanistic study of new dual targeting HDAC/tubulin inhibitors

Aim: The purpose of this work is to create and synthesize a new class of chemicals: 3-cyano-2-substituted pyridine compounds with expected multitarget inhibition of histone deacetylase (HDAC) and tubulin. Materials & methods: The target compounds (3a-c, 4a-c and 5a-c) were synthesized utilizing 6-(4-methoxyphenyl)-2-oxo-4-(3,4,5-trimethoxyphenyl)-3-cyanopyridine, with various linkers and zinc-binding groups (ZBGs). Results: Most of the tested compounds showed promising growth inhibition, and hydroxamic acid-containing hybrids possessed higher HDAC inhibition than other ZBGs. Compound 4b possessed the highest potency; however, it showed the most tubulin polymerization inhibition. Docking studies displayed good binding into HDAC1 and six pockets and tubulin polymerization protein. Conclusion: Compound 4b could be considered a good antitumor candidate to go further into in vivo and clinical studies.

Multi-targeted anti-Alzheimer's agents: Synthesis, biological evaluation, and molecular modeling study of some pyrazolopyridine hybrids

A new series of compounds bearing a pyrazolopyridine scaffold was synthesized as integrated anti-Alzheimer's disease (AD) multi-targeted ligands. Compounds 49 and 51 showed remarkable activity as hAChE inhibitors with IC50 values of 0.17 and 0.16 μM, respectively; and proved to be active hBuChE inhibitors with IC50 values 0.17 and 0.69 μM, eight and two-fold more active than the reference compound rivastigmine, respectively. Compounds 49 and 51 showed potent GSK3β inhibition with IC50 values of 0.21 and 0.26 μM, respectively compared to L807mts. Also, 49 and 51 showed 66.0 and 60.0% as tau protein aggregation inhibitors; and Aβ1-42 self-aggregation inhibitors with 79.0 and 75.0% respectively. Furthermore, 49 and 51 could bind virtually with the PAS affecting Aβ aggregation, thus preventing Aβ-dependent neurotoxicity. They proved to have the ability to chelate bio-metals such as Fe2+, Cu2+, and Zn2+ preventing their oxidative damage in the brain of AD patients, in addition to their safety upon WI-38 cell line. Both compounds could virtually penetrate BBB and obeyed Lipinski's rule of five. Compounds 49 and 51 could be considered as MTDLs for AD patients and the obtained model and pattern of substitution could be used for further development of new multi-targeted anti-Alzheimer's agents.

Quinazolin-4-one/3-cyanopyridin-2-one Hybrids as Dual Inhibitors of EGFR and BRAFV600E: Design, Synthesis, and Antiproliferative Activity

A novel series of hybrid compounds comprising quinazolin-4-one and 3-cyanopyridin-2-one structures has been developed, with dual inhibitory actions on both EGFR and BRAFV600E. These hybrid compounds were tested in vitro against four different cancer cell lines. Compounds 8, 9, 18, and 19 inhibited cell proliferation significantly in the four cancer cells, with GI50 values ranging from 1.20 to 1.80 µM when compared to Doxorubicin (GI50 = 1.10 µM). Within this group of hybrids, compounds 18 and 19 exhibited substantial inhibition of EGFR and BRAFV600E. Molecular docking investigations provided confirmation that compounds 18 and 19 possess the capability to inhibit EGFR and BRAFV600E. Moreover, computational ADMET prediction indicated that most of the newly synthesized hybrids have low toxicity and minimal side effects.

Design, Synthesis, and Biological Evaluation of Novel 3-Cyanopyridone/Pyrazoline Hybrids as Potential Apoptotic Antiproliferative Agents Targeting EGFR/BRAFV600E Inhibitory Pathways

A series of novel 3-cyanopyridone/pyrazoline hybrids (21-30) exhibiting dual inhibition against EGFR and BRAFV600E has been developed. The synthesized target compounds were tested in vitro against four cancer cell lines. Compounds 28 and 30 demonstrated remarkable antiproliferative activity, boasting GI50 values of 27 nM and 25 nM, respectively. These hybrids exhibited dual inhibitory effects on both EGFR and BRAFV600E pathways. Compounds 28 and 30, akin to Erlotinib, displayed promising anticancer potential. Compound 30 emerged as the most potent inhibitor against cancer cell proliferation and BRAFV600E. Notably, both compounds 28 and 30 induced apoptosis by elevating levels of caspase-3 and -8 and Bax, while downregulating the antiapoptotic Bcl2 protein. Molecular docking studies confirmed the potential of compounds 28 and 30 to act as dual EGFR/BRAFV600E inhibitors. Furthermore, in silico ADMET prediction indicated that most synthesized 3-cyanopyridone/pyrazoline hybrids exhibit low toxicity and minimal adverse effects.

Design, green synthesis, and quorum sensing quenching potential of novel 2-oxo-pyridines containing a thiophene/furan scaffold and targeting a LasR gene on P. aeruginosa

The current trend in fighting bacteria is attacking the virulence and quorum-sensing (QS) signals that control bacterial communication and virulence factors, especially biofilm formation. This study reports new Schiff bases and tetracyclic rings based on a pyridine pharmacophore by two methods: a green approach using CAN and a conventional method. The structure of designed derivatives was confirmed using different spectroscopies (IR and 1H/13C NMR) and elemental analysis. The designed derivatives exhibited good to moderate inhibition zones against bacterial and fungal pathogens. In addition, six compounds 2a,b, 3a,b, and 6a,b displayed potency against tested pathogens with eligible MIC and MBC values compared to standard antimicrobial agents. Compound 2a displayed MIC values of 15.6 μg mL-1 compared to Gentamicin (MIC = 250 μg mL-1 against K. pneumoniae), while compound 6b exhibited super-potent activity against P. aeruginosa, and K. pneumoniae with MIC values of 62.5 and 125 μg mL-1, as well as MBC values of 31.25 and 15.6 μg mL-1 compared to Gentamicin (MIC = 250 and 125 μg mL-1 and MBC = 62.5 μg mL-1), respectively. Surprisingly, these six derivatives revealed bactericidal and fungicidal potency and remarkable anti-biofilm activity that could significantly reduce the biofilm formation against MRSA, E. coli, P. aeruginosa, and C. albicans. Furthermore, the most active derivatives reduced the LasR gene's production between 10-40% at 1/8 MICs compared with untreated P. aeruginosa. Besides, they demonstrated promising safety profile on Vero cells (normal cell lines) with IC50 values ranging between (175.17 ± 3.49 to 344.27 ± 3.81 μg mL-1). In addition, the in silico ADMET prediction was carried out and the results revealed that these compounds could be used with oral bioavailability with low toxicity prediction when administered as a candidate drug. Finally, the molecular docking simulation was performed inside LasR and predicted the key binding interactions responsible for the activity that corroborated the biological results.

Cyanopyridinone- and Cyanopyridine-Based Cancer Cell Pim-1 Inhibitors: Design, Synthesis, Radiolabeling, Biodistribution, and Molecular Modeling Simulation

In this study, two new series of 3-cyanopyridinones (3a-e) and 3-cyanopyridines (4a-e) were synthesized and evaluated for their cytotoxicity and Pim-1 kinase inhibitory activity adopting 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay and in vitro Pim-1 kinase inhibition assay, respectively. Most of the tested compounds revealed promising cytotoxicity against HepG-2, HCT-116, MCF-7, and PC-3 cell lines. Among them, compounds 4c and 4d showed more potent cytotoxicity against the HePG2 cell line with IC₅₀ = 8.02 ± 0.38 and 6.95 ± 0.34 μM, respectively, than that of the reference 5-FU (IC₅₀ = 9.42 ± 0.46 μM). Moreover, compound 4c was more potent against HCT-116 (IC₅₀ = 7.15 ± 0.35 μM) than 5-FU (IC₅₀ = 8.01 ± 0.39 μM), while compound 4d with IC₅₀ = 8.35 ± 0.42 μM displayed comparable activity to that of the reference drug. Furthermore, high cytotoxic activity was manifested by compounds 4c and 4d against MCF-7 and PC3 cell lines. Our results have also indicated that compounds 4b, 4c, and 4d elicited remarkable inhibition of Pim-1 kinase; 4b and 4c showed equipotent inhibitory activity to that of the reference quercetagetin. Meanwhile, 4d displayed IC₅₀ = 0.46 ± 0.02 μM, showed the best inhibitory activity among the tested compounds, and was more potent than quercetagetin (IC₅₀ = 0.56 ± 0.03 μM). For optimization of the results, docking study of the most potent compounds 4c and 4d in the Pim-1 kinase active site was carried out and compared with both quercetagetin and the reported Pim-1 inhibitor A (VRV), and the results were consistent with those of the biological study. Consequently, compounds 4c and 4d are worthy of further investigations toward the discovery of Pim-1 kinase inhibitors as drug candidates for cancer therapy. Compound 4b was successfully radiolabeled with radioiodine-131, and its biodistribution in Ehrlich ascites carcinoma (EAC)-bearing mice showed more observable uptake in tumor sites, and hence, it can be introduced as a new radiolabeled agent for tumor imaging and therapy.

Light-induced one-pot synthesis of pyrimidine derivatives from vinyl azides

A one-pot procedure for the synthesis of tetrasubstituted dihydropyrimidine and pyrimidine derivatives from α-azidocinnamates was developed. The synthesis is based on the finding that the outcome of LED photolysis of α-azidocinnamates depends on the light wavelength employed. Blue light (455 nm) leads to the formation of 2H-azirines only, but violet light (395 nm), UV-A light (365 nm), or sunlight result in the transformation of the in situ formed 2H-azirines to 1,3-diazabicyclo[3.1.0]hex-3-enes. Under basic catalysis (DBU), the latter were isomerized to 1,6-dihydropyrimidines which were oxidized to pyrimidines using DDQ. A successful use of Cs2CO3 as a base and air as an oxidant was also demonstrated.

Discovery of Novel 3-Cyanopyridines as Survivin Modulators and Apoptosis Inducers

The overexpression of survivin is usually accompanied by an increased resistance of cancer cells to chemotherapeutic agents in addition to cancer aggressiveness. Consequently, survivin is considered as an attractive target to develop new promising anticancer candidates. A series of novel 3-cyanopyridine derivatives was synthesized and assessed for their cytotoxic activity against three human cancer cell lines: prostate carcinoma (PC-3), breast cancer (MDA-MB-231) and hepatocellular carcinoma (HepG2). In addition, their activities were evaluated in comparison with a standard anticancer drug 5-FU. Compounds 5c and 5e both exhibited promising cytotoxicity against all the tested cell lines; especially, 5e showed better cytotoxic effect than the reference drug 5-FU. In order to evaluate the safety of these compounds, they were tested on the normal cell line WI-38, revealing their toxic selectivity toward cancer cells over normal ones. Further studies were performed in order to understand their mechanism of action; we examined the ability of our promising compounds 5c and 5e to induce cell cycle arrest. Both resulted in a notable induction of cell cycle arrest at the G2/M phase, along with an increase in the DNA content in the pre-G1 phase, giving us an indication of the incidence of apoptosis. 5c and 5e were further subjected to additional study using Annexin V-FITC assay in order to evaluate their ability to induce apoptosis. The results showed a marked increase in the early and late apoptotic cells, as well as an increase in the percentage of necrosis. Furthermore, Western blotting assay was accomplished using different concentrations of 5c and 5e. The results revealed a striking reduction in survivin expression through proteasome-dependent survivin degradation in addition to a decrease in the expression of some other inhibitor of apoptosis proteins (IAP) family proteins: Livin, XIAP, and C-IAP1 in a concentration-dependent manner. A docking study of 5c and 5e compounds in the dimerization site of survivin was also performed, showing agreement with the in vitro anti-survivin activity.

New 2-Oxopyridine/2-Thiopyridine Derivatives Tethered to a Benzotriazole with Cytotoxicity on MCF7 Cell Lines and with Antiviral Activities

Background:

Perturbation of nucleic acids structures and confirmation by small molecules through intercalation binding is an intriguing application in anticancer therapy. The planar aromatic moiety of anticancer agents was inserted between DNA base pairs leading to change in the DNA structure and subsequent functional arrest.

Objective:

The final scaffold of the target compounds was annulated and linked to a benzotriazole ring. These new pharmacophoric features were examined as antiviral and anticancer agents against MCF7 and their effect on DNA damage was also assessed.

Methods:

A new series of fully substituted 2-oxopyridine/2-thioxopyridine derivatives tethered to a benzotriazole moiety (4a-h) was synthesized through Michael cyclization of synthesized α,β- unsaturated compounds (3a-e) with appropriate active methylene derivatives. The DNA damage study was assessed by comet assay. In silico DNA molecular docking was performed using Open Eye software to corroborate the experimental results and to understand molecule interaction at the atomic level.

Results:

The highest DNA damage was observed in Doxorubicin, followed by 4h, then, 4b, 4g, 4f, 4e, and 4d. The docking study showed that compound 4h formed Hydrogen Bonds (HBs) as a standard ligand with GSK-3. Compound 4h was the most active compound against rotavirus Wa, HAVHM175, and HSV strains with a reduction of 30%, 40%, and 70%, respectively.

Conclusion:

Compound 4h was the most active compound and could act as a prospective lead molecule for anticancer agent.

DBU-Mediated Cyclization of Acylcyclopropanecarboxylates with Amidines: Access to Polysubstituted Pyrimidines

DBU-mediated cyclization of 2-acyl-1-cyanocyclopropanecarboxylates with amidines for the synthesis of multisubstituted pyrimidine derivatives is described. This reaction gives a practical method for producing a diverse set of pyrimidines, having simple experimentation, readily available starting materials, a wide substrate scope, and very good yields.