A decade's overview of 2-aminothiophenes and their fused analogs as promising anticancer agents.

Over the past decades, cancer has been a challenging domain for medicinal chemists as it is an international health concern. In association, small molecules such as 2-aminothiophenes and their derivatives showed significant antitumor activity through variable modes of action. Therefore, this article aims to review the advances regarding these core scaffolds over the past 10 years, where 2-aminothiophenes and their fused analogs are classified and discussed according to their biological activity and mode of action, in the interest of boosting new design pathways for medicinal chemists to develop targeted antitumor candidates.

Development of 1,5-diarylpyrazoles as EGFR/JNK-2 dual inhibitors: design, synthesis, moleecular docking, and bioactivity evaluation.

The eradication of multifactorial diseases, such as cancer, requires the design of drug candidates that attack multiple targets that contribute to the progression and proliferation of such diseases. Here, 1,5-diarylpyrazole derivatives bearing vanillin or sulfanilamide are developed as potential dual inhibitors of epidermal growth factor receptor (EGFR)/c-Jun N-terminal kinase 2 (JNK-2) for possible anticancer activity. These derivatives inhibited the growths of DLD-1, HeLa, K-562, SUIT-2 and HepG2 cancer cell lines, with minimum concentration required to inhibit half of the cellular growth (IC50) values of 2.7-63 µM. The tests confirmed that 5b and 5d were potent JNK-2 inhibitors, with IC50 of 2.0 and 0.9 µM, respectively, whereas 6 h selectively inhibited EGFR protein kinase (EGFR-PK) (IC50 = 1.7 µM). Notably, 6c inhibited both kinases, with IC50 values of 2.7 and 3.0 µM against EGFR-PK and JNK-2, respectively, offering a reference for designing mutual inhibitors of EGFR/JNK-2. The docking studies revealed the ability of the pyrazole ring to bind to the hinge region of the ATP binding site, thereby supporting the experimental inhibitory results. Furthermore, the developed compounds could induce apoptosis and induce cell cycle arrest at different cell phases.

Development and Assessment of 1,5-Diarylpyrazole/Oxime Hybrids Targeting EGFR and JNK-2 as Antiproliferative Agents: A Comprehensive Study through Synthesis, Molecular Docking, and Evaluation.

New 1,5-diarylpyrazole oxime hybrid derivatives (scaffolds A and B) were designed, synthesized, and then their purity was verified using a variety of spectroscopic methods. A panel of five cancer cell lines known to express EGFR and JNK-2, including human colorectal adenocarcinoma cell line DLD-1, human cervical cancer cell line Hela, human leukemia cell line K562, human pancreatic cell line SUIT-2, and human hepatocellular carcinoma cell line HepG2, were used to biologically evaluate for their in vitro cytotoxicity for all the synthesized compounds 7a-j, 8a-j, 9a-c, and 10a-c. The oxime containing compounds 8a-j and 10a-c were more active as antiproliferative agents than their non-oxime congeners 7a-j and 9a-c. Compounds 8d, 8g, 8i, and 10c inhibited EGFR with IC50 values ranging from 8 to 21 µM when compared with sorafenib. Compound 8i inhibited JNK-2 as effectively as sorafenib, with an IC50 of 1.0 µM. Furthermore, compound 8g showed cell cycle arrest at the G2/M phase in the cell cycle analysis of the Hela cell line, whereas compound 8i showed combined S phase and G2 phase arrest. According to docking studies, oxime hybrid compounds 8d, 8g, 8i, and 10c exhibited binding free energies ranging from -12.98 to 32.30 kcal/mol at the EGFR binding site whereas compounds 8d and 8i had binding free energies ranging from -9.16 to -12.00 kcal/mol at the JNK-2 binding site.

New pyrimidine/thiazole hybrids endowed with analgesic, anti-inflammatory, and lower cardiotoxic activities: Design, synthesis, and COX-2/sEH dual inhibition.

Some cyclooxygenase (COX)-2 selective medications were withdrawn from the market just a few years after their production due to cardiovascular side effects. In this study, a new series of pyrimidine/thiazole hybrids 7a-p was synthesized as selective COX-2/soluble epoxide hydrolase (sEH) inhibitors with analgesic and anti-inflammatory effects, and lower cardiotoxicity effects. The target compounds were synthesized and in vitro tested against COX-1, COX-2, and sEH enzymes. Hybrids 7j, 7k, and 7i showed the greatest COX-2-inhibitory activity and were discovered to be the most potent dual COX-2/sEH inhibitors. In vivo tests revealed that these hybrids were the most active analgesic/anti-inflammatory agents, with improved ulcerogenic and cardioprotective properties. Finally, the most active dual inhibitors were docked into COX-2/sEH active regions to explain their binding mechanisms.

Molecular hybrids: A five-year survey on structures of multiple targeted hybrids of protein kinase inhibitors for cancer therapy.

Protein kinases have grown over the past few years as a crucial target for different cancer types. With the multifactorial nature of cancer, and the fast development of drug resistance for conventional chemotherapeutics, a strategy for designing multi-target agents was suggested to potentially increase drug efficacy, minimize side effects and retain the proper pharmacokinetic properties. Kinase inhibitors were used extensively in such strategy. Different kinase inhibitor agents which target EGFR, VEGFR, c-Met, CDK, PDK and other targets were merged into hybrids with conventional chemotherapeutics such as tubulin polymerization and topoisomerase inhibitors. Other hybrids were designed gathering kinase inhibitors with targeted cancer therapy such as HDAC, PARP, HSP 90 inhibitors. Nitric oxide donor molecules were also merged with kinase inhibitors for cancer therapy. The current review presents the hybrids designed in the past five years discussing their design principles, results and highlights their future perspectives.

Design, synthesis, and biological evaluation of new pyrimidine-5-carbonitrile derivatives bearing 1,3-thiazole moiety as novel anti-inflammatory EGFR inhibitors with cardiac safety profile.

A new series of pyrimidine-5-carbonitrile derivatives 8a-p carrying the 1,3-thiazole moiety has been designed and synthesized as novel anti-inflammatory EGFR inhibitors with cardiac and gastric safety profiles. 8a-p have been assessed for their inhibitory activity against COX-1/COX-2 activity. Compounds 8h, 8n, and 8p were found to be potent and selective COX-2 inhibitors (IC50 = 1.03-1.71 µM) relative to celecoxib (IC50 = 0.88 µM). The most potent COX-2 inhibitors have been further investigated for their in-vivo anti-inflammatory effect. Compounds 8h, 8n, and 8p showed anti-inflammatory activity up to 90%, 94% and 86% of meloxicam after 4 h interval. 8h, 8n, and 8p showed higher gastric safety profiles than meloxicam. A substantial reduction in serum concentrations of PGE2, TNF-α, IL-6, iNO and MDA and a significant induction of TAC was also observed. In vivo experiments on heart rate and blood pressure established the cardiovascular safety profile of 8h, 8n, and 8p. Anti-proliferative and wild-type EGFR inhibitory assays displayed similar results to selective COX-2 inhibition where compounds 8h, 8n, and 8p had a superior inhibition than other tested ones. Molecular docking study demonstrated that these compounds revealed similar orientation and binding interactions as selective COX-2 inhibitors with a higher liability to enter the side pocket selectively. Also, they interacted with EGFR tyrosine kinase main amino acids similar to erlotinib with a strong binding energy score.

Design, synthesis, and antibacterial evaluation of new quinoline-1,3,4-oxadiazole and quinoline-1,2,4-triazole hybrids as potential inhibitors of DNA gyrase and topoisomerase IV.

DNA gyrase and topoisomerase IV (topo IV) inhibitors are among the most interesting antibacterial drug classes without antibacterial pipeline representative. Twenty-four new quinoline-1,3,4-oxadiazole and quinoline-1,2,4-triazole hybrids were developed and tested against DNA gyrase and topoisomerase IV from Escherichia coli and Staphylococcus aureus. The most potent compounds 4c, 4e, 4f, and 5e displayed an IC50 of 34, 26, 32, and 90 nM against E. coli DNA gyrase, respectively (novobiocin, IC50 = 170 nM). The activities of 4c, 4e, 4f, and 5e on DNA gyrase from S. aureus were weaker than those on E. coli gyrase. Compound 4e showed IC50 values (0.47 µM and 0.92 µM) against E. coli topo IV and S. aureus topo IV, respectively in comparison to novobiocin (IC50 = 11, 27 µM, respectively). Antibacterial activity against Gram-positive and Gram-negative bacterial strains has been studied. Some compounds have demonstrated superior antibacterial activity to ciprofloxacin against some of the bacterial strain studied. The most active compounds in this study showed no cytotoxic effect with cell viability>86%. Finally, a molecular docking analysis was performed to investigate the binding mode and interactions of the most active compounds to the active site of DNA gyrase and topoisomerase IV (topo IV) enzymes.

JNK signaling as a target for anticancer therapy.

The JNKs are members of mitogen-activated protein kinases (MAPK) which regulate many physiological processes including inflammatory responses, macrophages, cell proliferation, differentiation, survival, and death. It is increasingly clear that the continuous activation of JNKs has a role in cancer development and progression. Therefore, JNKs represent attractive oncogenic targets for cancer therapy using small molecule kinase inhibitors. Studies showed that the two major JNK proteins JNK1 and JNK2 have opposite functions in different types of cancers, which need more specification in the design of JNK inhibitors. Some of ATP- competitive and ATP non-competitive inhibitors have been developed and widely used in vitro, but this type of inhibitors lack selectivity and inhibits phosphorylation of all JNK substrates and may lead to cellular toxicity. In this review, we summarized and discussed the strategies of JNK binding inhibitors and the role of JNK signaling in the pathogenesis of different solid and hematological malignancies.

Synthesis, antitumor, antibacterial and urease inhibitory evaluation of new piperazinyl N-4 carbamoyl functionalized ciprofloxacin derivatives.

BACKGROUND: Quinolones are well known antibacterial chemotherapeutics. Furthermore, they were reported for other activities such as anticancer and urease inhibitory potential. Modification at C7 of quinolones can direct these compounds preferentially toward target molecules. METHODS: Different derivatives of ciprofloxacin by functionalization at the piperazinyl N-4 position with arylidenehydrazinecarbonyl and saturated heterocyclic-carbonyl moieties have been synthesized and characterized using different spectral and analytical techniques. The synthesized compounds were evaluated for anticancer, antibacterial, and urease inhibitory activities. RESULTS: Among the synthesized compounds derivatives 3f and 3g experienced a potent antiproliferative activity against the breast cancer BT-549 cell line, recording growth percentages of 28.68% and 6.18%, respectively. Additionally, compound 3g revealed a remarkable antitumor potential toward the colon cancer HCT-116 cells (growth percentage 14.76%). Activity of compounds 3f and 3g against BT-549 cells was comparable to doxorubicin (IC50 = 1.84, 9.83, and 1.29 µM, respectively). Test compounds were less active than their parent drug, ciprofloxacin toward Klebsiella pneumoniae and Proteus mirabilis. However, derivative 4a showed activity better than chloramphenicol against Klebsiella pneumoniae (MIC = 100.64 and 217.08 µM, respectively). Meanwhile, many of the synthesized compounds revealed a urease inhibitory activity greater than their parent. Compound 3i was the most potent urease inhibitor with IC50 of 58.92 µM, greater than ciprofloxacin and standard inhibitor, thiourea (IC50 = 94.32 and 78.89 µM, respectively). CONCLUSION: This study provided promising derivatives as lead compounds for development of anticancer agents against breast and colon cancers, and others for optimization of urease inhibitors.

Design and synthesis of pyrimidine-5-carbonitrile hybrids as COX-2 inhibitors: Anti-inflammatory activity, ulcerogenic liability, histopathological and docking studies.

Two new series of 1,3,4-oxadiazole and coumarin derivatives based on pyrimidine-5-carbonitrile scaffold have been synthesized and evaluated for their COX-1/COX-2 inhibitory activity. Compounds 10c, 10e, 10h-j, 14e-f, 14i and 16 were found to be the most potent and selective inhibitors of COX-2 (IC50 0.041-0.081 µM, SI 139.74-321.95). Eight compounds were further investigated for their in vivo anti-inflammatory activity. The most active derivatives 10c, 10j and 14e displayed superior in vivo anti-inflammatory activity (% edema inhibition 39.3-48.3, 1 h; 58.4-60.5, 2 h; 70.8-83.2, 3 h; 78.9-89.5, 4 h) to the reference drug celecoxib (% edema inhibition 38.0, 1 h; 48.8, 2 h; 58.4, 3 h; 65.4, 4 h). These derivatives were also tested for their ulcerogenic liability, compound 10j showed better safety profile with reference to celecoxib while 10c and 14e exhibited mild lesions. Molecular docking studies of 10c, 10j, and 14e in the COX-2 active site revealed similar orientation and binding interactions as selective COX-2 inhibitors with a higher liability to access the selectivity side pocket.

Design and synthesis of new 1,6-dihydropyrimidin-2-thio derivatives targeting VEGFR-2: Molecular docking and antiproliferative evaluation.

A series of new 1,6-dihydropyrimidin-2-thiol derivatives (scaffold A) as VEGFR-2 inhibitors has been designed and synthesized. Compounds 3a, 3b, 3e and 4b have been selected for in vitro anticancer screening by the National Cancer Institute. Compound 3e showed remarkable anticancer activity against most of the cell lines tested, where a complete cell death against leukemia, non-small cell lung cancer, colon, CNS, melanoma, and breast cancer cell lines was observed. In vitro five dose tests showed that compound 3e had high activity against most of the tested cell lines with GI50 ranging from 19 to 100 µM and selectivity ratios ranging between 0.75 and 1.71 at the GI50 level. VEGFR-2-kinase was tested against 3a, 3b, 3e, 4b and sorafenib was used as a reference. Compounds 3a and 3e were the most potent analogues with IC50 values of 386.4 nM and 198.7 nM against VEGFR-2, respectively, in comparison to sorafenib (IC50 = 0.17 nM). The results of the docking study showed a good fitting of the new compounds to the active site of VEGFR-2 with binding free energies in the range of -9.80 to -11.25 kcal/mol compared to -12.12 kcal/mol for sorafenib. Compounds 4a-e with the hydroxyimino group had a higher affinity to VEGFR-2 than their parent derivatives 3a-e.

Design, synthesis and biological evaluation of some new 1,3,4-thiadiazine-thiourea derivatives as potential antitumor agents against non-small cell lung cancer cells.

New 1,3,4-thiadiazine-thiourea derivatives have been synthesized. All the synthesized compounds were examined for in vitro cytotoxic activity against Non-Small Cell Lung Cancer (NSCLC) cell line A549, using MTT bioassay. Compounds 5d, 5i, 5j showed the highest cytotoxic activity with IC50 values of 0.27 ±â€¯0.01, 0.30 ±â€¯0.02, and 0.32 ±â€¯0.012 µM respectively with sorafenib as reference (IC50 3.85 ±â€¯0.27 µM). These compounds were chosen for further investigations against various biological targets known to play roles in NSCLC specifically: vascular endothelial growth factor receptor 2 (VEGFR2), B-RAF and matrix metalloproteinase 9 (MMP9). Encouraging results were exhibited by the three compounds against the selected targets. Compound 5j was specially promising as it exhibited inhibitory activity of VEGFR2 close to sorafenib (IC50 0.11 ±â€¯0.01 µM), most potent B-RAF activity inhibition (IC50 0.178 ±â€¯0.004 µM) and MMP9 inhibition (IC50 0.08 ±â€¯0.004 µM). Moreover, cell cycle analysis of A549 cells treated with 5j exhibited cell cycle arrest at G2-M phase and pro-apoptotic activity as indicated by Annexin V-FITC staining. Also, it reflected antinvasive and antimigration properties to A549 cells. Additionally, docking study of 5j on VEGFR2, B-RAF and MMP9 revealed that it binds to the target enzymes in a similar way as the co-crystallized ligand. The three compounds exhibited significantly high selectivity to A549 cancer cells against the normal human fetal lung fibroblast cell line WI-38 with higher selectivity index compared to sorafenib (5d IC50 136.76 ±â€¯2.38 µM, SI = 506.52; 5i IC50 89.20 ±â€¯2.11 µM, SI = 297.33; 5j IC50 79.60 ±â€¯3.8 µM, SI = 248.75; sorafenib IC50 30.32 ±â€¯2.41 µM, SI = 7.88). In conclusion, compounds 5d, 5i and 5j, specially 5j are promising anticancer agents targeting important pathways in NSCLC and warrant further preclinical and clinical trials.

Towards anticancer fluoroquinolones: A review article.

Different studies about the anticancer potential of several medically used antibacterial fluoroquinolones have been established. Fluoroquinolone derivatives, like some anti-cancer drugs, such as doxorubicin, can achieve antitumor activity via poisoning of type II human DNA topoisomerases. Interestingly, structural features required for the anticancer activity of quinolones have been determined. Most of the chemical modifications required to convert antibacterially acting fluoroquinolones into their anticancer analogs were at position 7 and the carboxylic group at position 3. This review highlights the antitumor potential of fluoroquinolones in general and summarizes the chemical modifications carried out on fluoroquinolones to become anticancer agents. Moreover, the review gives a quick recap on metal ion chelates with fluoroquinolones and their substantial role in topoisomerase poisoning and antitumor potential improvement. Hence, it should be highly interesting for researchers attempting to design and synthesize novel anticancer fluoroquinolone candidates.

Design, synthesis and anticancer activity of new monastrol analogues bearing 1,3,4-oxadiazole moiety.

A series of dihydropyrimidine (DHPM) derivatives bearing 1,3,4-oxadiazole moiety was designed and synthesized as monastrol analogues. The new compounds were screened for their cytotoxic activity toward 60 cancer cell lines according to NCI (USA) protocol. Seven compounds were further examined against the most sensitive cell lines, leukemia HL-60(TB) and MOLT-4. The most active compounds were 9m against HL-60(TB) (IC50 = 56 nM) and 9n against MOLT-4 (IC50 = 80 nM), more potent than monastrol (IC50 = 147 and 215 nM, respectively). Cell cycle analysis of HL-60(TB) cells treated with 9m and MOLT-4 cells treated with 9n showed cell cycle arrest at G2/M phase and pro-apoptotic activity as indicated by annexin V-FITC staining.

Synthesis, cyclooxygenase inhibition and anti-inflammatory evaluation of new 1,3,5-triaryl-4,5-dihydro-1H-pyrazole derivatives possessing methanesulphonyl pharmacophore.

A new series of 1,3,5-triaryl-4,5-dihydro-1H-pyrazole derivatives 13a-p were synthesized via aldol condensation of 3/4-nitroacetophenones with appropriately substituted aldehydes followed by cyclization of the formed chalcones with 4-methanesulfonylphenylhydrazine hydrochloride. All the synthesized compounds were evaluated for their cyclooxygenase (COX) inhibition, anti-inflammatory activity and ulcerogenic liability. All compounds were more potent inhibitors for COX-2 than COX-1. While most compounds showed good anti-inflammatory activity, compounds 13d, 13f, 13k and 13o were the most potent derivatives (ED50 = 66.5, 73.4, 79.8 and 70.5 µmol/kg, respectively) in comparison with celecoxib (ED50 = 68.1 µmol/kg). Compounds 13d, 13f, 13k and 13o (ulcer index = 3.89, 4.86, 4.96 and 3.92, respectively) were 4-6 folds less ulcerogenic than aspirin (ulcer index = 22.75) and showed approximately ulceration effect similar to celecoxib (ulcer index = 3.35). In addition, molecular docking studies were performed for compounds 13d, 13f, 13k and 13o inside COX-2 active site which showed acceptable binding interactions (affinity in kcal/mol -2.1774, -6.9498) in comparison with celecoxib (affinity in kcal/mol -6.5330).

Design and synthesis of some substituted thiazolo[3,2-a]pyrimidine derivatives of potential biological activities.

In continuation to our previous work, thiazolopyrimidines 2a-x were synthesized through intramolecular cyclization of 2-phenacylthio-dihydropyrimidine hydrobromides 1a-x using polyphosphoric acid. On the other hand, thiazolo[3,2-a]pyrimidine-3-one 3 was coupled with aryldiazonium salts or condensed with isatin to afford compounds 4a-c or 5, respectively. Chemical structure of the target compounds was substantiated by IR, FT-IR, (1)H-, (13)C and DEPT-(13)C NMR, MS as well as microanalyses. Moreover, the lipophilicity of the target compounds is expressed as Clog P. The antimicrobial screening of the test compounds 2a-x, 4a-c and 5 revealed moderate activity in comparison to reference drugs. Compounds 2a-c, 2e, 2o and 2v showed a gradual increase in their anti-inflammatory activity reaching its maximum at 5 h compared to indomethacin. Furthermore, the analgesic activity of compounds 2a-c, 2e, 2o and 2v revealed a maximum activity after 5 h of injection compared to aspirin and the LD50 of compounds 2e and 2v was determined.