Designing Potent Anti-Cancer Agents: Synthesis and Molecular Docking Studies of Thieno[2,3-d][1,2,4]triazolo[1,5-a]pyrimidine Derivatives

A new series of thieno[2,3-d][1,2,4]triazolo[1,5-a]pyrimidines was designed and synthesized using readily available starting materials, specifically, β-enaminoester. Their cytotoxicity was screened against three cancer cell lines, namely, MCF-7, HCT-116, and PC-3. 2-(4-bromophenyl)triazole 10b and 2-(anthracen-9-yl)triazole 10e afforded excellent potency against MCF-7 cell lines (IC50 = 19.4 ± 0.22 and 14.5 ± 0.30 μM, respectively) compared with doxorubicin (IC50 = 40.0 ± 3.9 μM). The latter derivatives 10b and 10e were further subjected to in silico ADME and docking simulation studies against EGFR and PI3K and could serve as ideal leads for additional modification in the field of anticancer research.

Nanoparticles of a Pyrazolo-Pyridazine Derivative as Potential EGFR and CDK-2 Inhibitors: Design, Structure Determination, Anticancer Evaluation and In Silico Studies

The strategic planning of this study is based upon using the nanoformulation method to prepare nanoparticles 4-SLNs and 4-LPHNPs of the previously prepared 4,5-diphenyl-1H-pyrazolo[3,4-c]pyridazin-3-amine (4) after confirming its structure with single crystal X-ray analysis. These nanoparticles exhibited promising cytotoxic activity against HepG-2, HCT-116 and MCF-7 cancer cell lines in comparison with the reference doxorubicin and the original derivative 4. Moreover, their inhibitory assessment against EGFR and CDK-2/cyclin A2 displayed improved and more favorable impact than the parent 4 and the references. Detection of their influence upon cancer biomarkers revealed upregulation of Bax, p53 and caspase-3 levels and downregulation of Bcl-2 levels. The docking simulation demonstrated that the presence of the pyrazolo[3,4-c]pyridazin-3-amine scaffold is amenable to enclosure and binding well within EGFR and CDK-2 receptors through different hydrophilic interactions. The pharmacokinetic and physicochemical properties of target 4 were also assessed with ADME investigation, and the outcome indicated good drug-like characteristics.

New Thiophenyl-pyrazolyl-thiazole Hybrids as DHFR Inhibitors: Design, Synthesis, Antimicrobial Evaluation, Molecular Modeling, and Biodistribution Studies

The antibiotic resistance problems constitute a considerable threat to human health worldwide; thus, the discovery of new antimicrobial candidates to conquer this issue is an imperative requirement. From this view, new thiophenyl-pyrazolyl-thiazole hybrids 3-10 were synthesized and screened for their antibacterial efficiency versus Gram - and Gram + bacterial strains compared to the reference drug amoxicillin. It was noticed that the new hybrids displayed significant antibacterial efficacy versus Gram - bacteria, especially against Pseudomonas aeruginosa. Also, all the screened candidates demonstrated a noticeable antifungal effect against Candida albicans (MICs = 3.9-125 μg/mL) relative to fluconazole (MIC = 250 μg/mL). Moreover, the new hybrids were investigated for their antituberculosis potency against Mycobacterium tuberculosis (RCMB 010126). Derivatives 4c, 6b, 8b, 9b, and 10b demonstrated prominent antituberculosis efficiency (MICs = 0.12-1.95 μg/mL) compared with the reference drug isoniazid (MIC = 0.12 μg/mL). The latter derivatives were further assessed for their inhibitory potency versus M. tuberculosis DHFR enzyme. The compounds 4c, 6b and 10b presented a remarkable suppression effect with IC50 values of 4.21, 5.70, and 10.59 μM, respectively, compared to that of trimethoprim (IC50 = 6.23 μM). Furthermore, biodistribution profile using radiolabeling way revealed a perceived uptake of 131I-compound 6b into infection induced models. The docking study for the new hybrids 4c, 6b, 8b, 9b and 10b was performed to illustrate the various binding modes with Mtb DHFR enzyme. In silico ADMET studies for the most potent inhibitors 4c, 6b and 10b were also accomplished to predict their pharmacokinetic and physicochemical features.

New pyrazolopyridine and pyrazolothiazole-based compounds as anti-proliferative agents targeting c-Met kinase inhibition: design, synthesis, biological evaluation, and computational studies

c-Met tyrosine kinase plays a key role in the oncogenic process. Inhibition of the c-Met has emerged as an attractive target for human cancer treatment. This work deals with the design and synthesis of a new set of derivatives bearing pyrazolo[3,4-b]pyridine, pyrazolo[3,4-b]thieno[3,2-e]pyridine, and pyrazolo[3,4-d]thiazole-5-thione scaffolds, 5a,b, 8a-f, and 10a,b, respectively, utilizing 3-methyl-1-tosyl-1H-pyrazol-5(4H)-one (1) as a key starting material. All the new compounds were evaluated as antiproliferative agents against HepG-2, MCF-7, and HCT-116 human cancer cell lines utilizing 5-fluorouracil and erlotinib as two standard drugs. Compounds 5a,b and 10a,b represented the most promising cytotoxic activity of IC₅₀ values ranging from 3.42 ± 1.31 to 17.16 ± 0.37 μM. Both 5a and 5b showed the most cytotoxicity and selectivity toward HepG-2, with IC₅₀ values of 3.42 ± 1.31 μM and 3.56 ± 1.5 μM, respectively. The enzyme assay demonstrated that 5a and 5b had inhibition potency on c-Met with IC₅₀ values in nanomolar range of 4.27 ± 0.31 and 7.95 ± 0.17 nM, respectively in comparison with the reference drug cabozantinib (IC₅₀; 5.38 ± 0.35 nM). The impact of 5a on the cell cycle and apoptosis induction potential in HepG-2 and on the apoptotic parameters; Bax, Bcl-2, p53, and caspase-3 was also investigated. Finally, the molecular docking simulation of the most promising derivatives 5a and 5b was screened against c-Met to investigate the binding patterns of both compounds in the active site of the c-Met enzyme. In silico ADME studies were also performed for 5a and 5b to predict their physicochemical and pharmacokinetic characteristics.

Design, synthesis, and anti-cancer evaluation of new pyrido[2,3-d]pyrimidin-4(3H)-one derivatives as potential EGFRWT and EGFRT790M inhibitors and apoptosis inducers

A new series of pyrido[2,3-d]pyrimidin-4(3H)-one derivatives having the essential pharmacophoric features of EGFR inhibitors has been designed and synthesised. Cell viability screening was performed for these compounds against A-549, PC-3, HCT-116, and MCF-7 cell lines at a dose of 100 μM. The highest active derivatives (8a, 8 b, 8d, 9a, and 12b) were selected for IC₅₀ screening. Compounds 8a, 8 b, and 9a showed the highest cytotoxic activities and were further investigated for wild EGFR^WT and mutant EGFR^T790M inhibitory activities. Compound 8a showed the highest inhibitory activities against EGFR^WT and EGFR^T790M with IC₅₀ values of 0.099 and 0.123 µM, respectively. In addition, it arrested the cell cycle at pre-G1 phase and induced a significant apoptotic effect in PC-3 cells. Furthermore, compound 8a induced a 5.3-fold increase in the level of caspase-3 in PC-3 cells. Finally, docking studies were carried out to examine the binding mode of the synthesised compounds against both EGFR^WT and EGFR^T790M.

Design, Synthesis, Anticancer Activity and Molecular Docking of New 1,2,3-Triazole-Based Glycosides Bearing 1,3,4-Thiadiazolyl, Indolyl and Arylacetamide Scaffolds

New 1,3,4-thiadiazole thioglycosides linked to a substituted arylidine system were synthesized via heterocyclization via click 1,3-dipolar cycloaddition. The click strategy was used for the synthesis of new 1,3,4-thiadiazole and 1,2,3-triazole hybrid glycoside-based indolyl systems as novel hybrid molecules by reacting azide derivatives with the corresponding acetylated glycosyl terminal acetylenes. The cytotoxic activities of the compounds were studied against HCT-116 (human colorectal carcinoma) and MCF-7 (human breast adenocarcinoma) cell lines using the MTT assay. The results showed that the key thiadiazolethione compounds, the triazole glycosides linked to p-methoxyarylidine derivatives and the free hydroxyl glycoside had potent activity comparable to the reference drug, doxorubicin, against MCF-7 human cancer cells. Docking simulation studies were performed to check the binding patterns of the synthesized compounds. Enzyme inhibition assay studies were also conducted for the epidermal growth factor receptor (EGFR), and the results explained the activity of a number of derivatives.

New thiophene, thienopyridine and thiazoline-based derivatives: Design, synthesis and biological evaluation as antiproliferative agents and multitargeting kinase inhibitors

Multitargeting kinase inhibitors recently proved to be a profitable approach for conquering cancer proliferation. The current study represents the design and synthesis of new thiophene, thienopyridine, and thiazoline-based derivatives 4-14a,b. All the target compounds were examined in vitro against three cancer cell lines; the liver (HepG-2), breast (MCF-7), and colon (HCT-116) where the thiophene-based compounds 5a-c, demonstrated the most potent activity. Furthermore, the latter derivatives revealed a safety profile against WI-38 normal cell line of selectivity indices ranging from 4.43 to 17.44. In vitro enzyme assay of 5a-c revealed that the carbohydrazide analog 5c has the most promising multitargeting inhibiting activity against Pim-1, VEGFR-2, and EGFR^WT enzymes of IC₅₀ values; 0.037 ± 0.02, 0.95 ± 0.24, and 0.16 ± 0.05 µM, respectively. As it was the most potent analog, 5c was further subjected to cell cycle and apoptosis analysis. The results indicated that it induced preG1 arrest and an apoptotic effect in the early and late stages. Moreover, further apoptosis studies were carried out for 5c to evaluate its proapoptotic potential. Interestingly, 5c enhanced the levels of Bax/Bcl-2 ratio, p53, and active caspase 3 by 18, 6.4, and 24 folds, respectively compared to the untreated cells. The antimicrobial evaluation showed that only compounds 3 and 5a produced broad-spectrum potency, while 5b and 5c exhibited outstanding antifungal effects. Finally, a molecular docking study was carried out to discover the probable interactions of compound 5c with the active sites of Pim-1, VEGFR-2, and EGFR^WT kinases.

New Benzimidazole-, 1,2,4-Triazole-, and 1,3,5-Triazine-Based Derivatives as Potential EGFRWT and EGFRT790M Inhibitors: Microwave-Assisted Synthesis, Anticancer Evaluation, and Molecular Docking Study

A new series of benzimidazole, 1,2,4-triazole, and 1,3,5-triazine derivatives were designed and synthesized using a microwave irradiation synthetic approach utilizing 2-phenylacetyl isothiocyanate (1) as a key starting material. All the new analogues were evaluated as anticancer agents against a panel of cancer cell lines utilizing doxorubicin as a standard drug. Most of the tested derivatives exhibited selective cytotoxic activity against MCF-7 and A-549 cancer cell lines. Furthermore, the new target compounds 5, 6, and 7 as the most potent antiproliferative agents have been assessed as in vitro EGFR^WT and EGFR^T790M inhibitors compared to the reference drugs erlotinib and AZD9291. They represented more potent suppression activity against the mutated EGFR^T790M than the wild-type EGFR^WT. Moreover, the compounds 5, 6, and 7 down-regulated the oncogenic parameter p53 ubiquitination. A docking simulation of compound 6b was carried out to correlate its molecular structure with its significant EGFR inhibition potency and its possible binding interactions within the active site of EGFR^WT and the mutant EGFR^T790M.

Identification of Antibacterial Metabolites from Endophytic Fungus Aspergillus fumigatus, Isolated from Albizia lucidior Leaves (Fabaceae), Utilizing Metabolomic and Molecular Docking Techniques

The rapid spread of bacterial infection caused by Staphylococcus aureus has become a problem to public health despite the presence of past trials devoted to controlling the infection. Thus, the current study aimed to explore the chemical composition of the extract of endophytic fungus Aspergillus fumigatus, isolated from Albizia lucidior leaves, and investigate the antimicrobial activity of isolated metabolites and their probable mode of actions. The chemical investigation of the fungal extract via UPLC/MS/MS led to the identification of at least forty-two metabolites, as well as the isolation and complete characterization of eight reported metabolites. The antibacterial activities of isolated metabolites were assessed against S. aureus using agar disc diffusion and microplate dilution methods. Compounds ergosterol, helvolic acid and monomethyl sulochrin-4-sulphate showed minimal inhibitory concentration (MIC) values of 15.63, 1.95 and 3.90 µg/mL, respectively, compared to ciprofloxacin. We also report the inhibitory activity of the fungal extract on DNA gyrase and topoisomerase IV, which led us to perform molecular docking using the three most active compounds isolated from the extract against both enzymes. These active compounds had the required structural features for S. aureus DNA gyrase and topoisomerase IV inhibition, evidenced via molecular docking.

Antibacterial and anticancer profiling of new benzocaine derivatives: Design, synthesis, and molecular mechanism of action

The need for new chemotherapeutics to overcome development of resistance merits research to discover new agents. Benzocaine derivatives are essential compounds in medicinal chemistry due to their various biological activities including antibacterial and anticancer activities. Therefore, this study focuses on the synthesis of new benzocaine derivatives 3a-e, 6, 7a and 7b, 8, 10-14, and 16a-d and their in vitro evaluation as antibacterial agents against gram +ve and -ve strains and as anticancer agents against HepG-2, HCT-116, and MCF-7 human cancer cell lines. The obtained results demonstrated that thiazolidines 6 and 7b showed higher antibacterial and anticancer activity in comparison with the reference drugs. In addition, 6 and 7b showed high potency as inhibitors toward their biological targets, that is DNA gyrase and human topoisomerase IIα, as compared to the reference standard drugs novobiocin and etoposide, respectively. Molecular docking demonstrated that both compounds could identify the active site of their target enzymes and develop effective binding interactions. Absorption, distribution, metabolism and elimination (ADME) and drug-likeness predictions of both compounds showed that they both have good ADME profiles and no structural alerts that might cause toxicity. Based on this, 6 and 7b could serve as lead compounds for the design of more potent antibacterial and anticancer agents.

Synthesis and biological evaluation of new derivatives of thieno-thiazole and dihydrothiazolo-thiazole scaffolds integrated with a pyrazoline nucleus as anticancer and multi-targeting kinase inhibitors

Deregulation of various protein kinases is considered as one of the important factors resulting in cancer development and metastasis, thus multi-targeting the kinase family is one of the most important strategies in current cancer therapy. This context represents the design and synthesis of two sets of derivatives bearing a pyrazoline-3-one ring conjugated either with a thieno[3,2-d]thiazole or with a dihydrothiazolo[4,5-d]thiazole scaffold via an NH linker, 3a–d and 5a–d respectively, using the pyrazolinone–thiazolinone derivative 1 as a key precursor. All the newly synthesized compounds were assessed in vitro for their anticancer activity against two cancer cell lines (MCF-7 and HepG-2). The safety profile of the most active cytotoxic candidates 1 and 3c was further examined against the normal cell line WI-38. The compounds 1 and 3c were further evaluated as multi-targeting kinase inhibitors against EGFR, VEGFR-2 and BRAF^V600E, exhibiting promising suppression impact. Additionally, the latter compounds were investigated for their impact on cell cycle and apoptosis induction potential in the MCF-7 cell line. Moreover, the antimicrobial activity of all the new analogues was evaluated against a panel of Gram-positive and Gram-negative bacteria, yeast and fungi in comparison to streptomycin and amphotericin-B as reference drugs. Interestingly, both 1 and 3c showed the most promising microbial inhibitory effect. Molecular docking studies showed promising binding patterns of the compounds 1 and 3c with the prospective targets, EGFR, VEGFR-2 and BRAF^V600E. Finally, additional toxicity studies were performed for the new derivatives which showed their good drug-like properties and low toxicity risks in humans.

Deregulation of various protein kinases is considered as one of the important factors resulting in cancer development and metastasis, thus multi-targeting the kinase family is one of the most important strategies in current cancer therapy.

Click chemistry based synthesis, cytotoxic activity and molecular docking of novel triazole-thienopyrimidine hybrid glycosides targeting EGFR

In the current study, new thienopyrimidine conjugates bearing 1,2,3-triazole core and different sugar moieties have been designed and synthesized by Cu(I)-catalysed click dipolar cycloaddition. The cytotoxic activity of the synthesised conjugates 2, 5, 7, and 13-18 was studied against HCT-116 and MCF-7 cell lines by the MTT assay. The triazole glycosides 16 and 18 provided significant cytotoxic activities against HCT-116 cell lines comparable to that of doxorubicin and other studied compounds. The cytotoxic behaviour against MCF-7 exhibited that all the investigated compounds were more potent than doxorubicin. Moreover, all screened targets were evaluated against mutant EGFR kinase type L858R and the results revealed that the acetylated 1,2,3-triazole glycosides 13-18 exhibited excellent EGFR inhibitory activity in comparison with gefitinib. Furthermore, molecular modelling studies were performed to investigate the binding affinity of the most active compounds to EGFR enzyme.

Synthesis, anticancer evaluation and molecular docking of new benzothiazole scaffolds targeting FGFR-1

This work deals with the design and synthesis of a series of new substituted 2-arylbenzothiazole compounds attached to 4-oxothiazolidin-2-ylidene ring 2-12 and chain elongation with different amino acids and their corresponding ester derivatives 13-18. All prepared derivatives were screened for their in vitro cytotoxicity activities against two cancer cell lines (HepG-2 and MCF-7) in comparison with doxorubicin; in addition to their safety towards thenormal cell line. Furthermore, all compounds 2-18 were evaluated as FGFR-1 inhibitors using AZD4547 as a reference. The 4-oxothiazolidin-2-ylidene derivatives 3 and 8 exhibited the highest cytotoxic activity (IC_{50 HepG-2} = 2.06, 2.21 µM and IC_{50 MCF-7} = 0.73, 0.77 µM, respectively) through their promising FGFR-1 suppression effects (IC₅₀ = 16.31 and 18.08 nM, respectively) in comparison to AZD4547 (IC₅₀ = 21.45 nM). Cell cycle and apoptosis analysis indicated that compounds 3 and 8 induce pronounced increase in the cell percentages at pre-G₁ and G₂/M phase compared to the untreated MCF-7 cancer cells, in addition to their up regulation of caspase-3/7/9. The molecular docking simulation was created to elucidate the binding modes of benzothiazole derivatives 1-18 bearing various scaffolds within the ATP-binding pocket of FGFR-1 enzyme compared with AZD4547.

Synthesis, anticancer activity and molecular docking of new triazolo[4,5-d]pyrimidines based thienopyrimidine system and their derived N-glycosides and thioglycosides

A series of new substituted triazolo[4,5-d]pyrimidine derivatives linked to thienopyrimidine ring system were prepared as a hybrid heterocyclic systems, as possible nucleobases analogs, starting from the key carboxamide derivative 2 and its azide precursor via heterocyclization reactions and their structures were characterized. Glycosylation of the prepared triazolopyrimidine derivatives was performed and afforded, regioselctively, the corresponding thienopyrimidine-triazolopyrimidine hybrid N¹-glycosides and their thioglycoside analogues in good yields. The synthesized glycosyl heterocycles were studied for their cytotoxic activity against HepG-2 and MCF-7 human cancer cells and significant results were obtained. Compounds 7a, 8 b, 9 b, 9a and 7 b demonstrated promising activities comparable to the activity of the doxorubicin for (HepG-2) cell line. Furthermore, a number of the afforded triazolopyrimidine glycosides were found potent against cancer cells (MCF-7). Furthermore, docking simulation the promising thienopyrimidine analogues 7-13 was done against EGFR kinase to provide a binding model that could serve in discovery of further anticancer agents.

New quinoline-triazole conjugates: Synthesis, and antiviral properties against SARS-CoV-2

At present therapeutic options for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are very limited. We designed and synthesized three sets of small molecules using quinoline scaffolds. A series of quinoline conjugates (10a-l, 11a-c, and 12a-e) by incorporating 1,2,3-triazole were synthesized via a modified microwave-assisted click chemistry technique. Among the synthesized conjugates, 4-((1-(2-chlorophenyl)-1H-1,2,3-triazol-4-yl)methoxy)-6-fluoro-2-(trifluoromethyl)quinoline (10g) and 6-fluoro-4-(2-(1-(4-methoxyphenyl)-1H-1,2,3-triazol-4-yl)ethoxy)-2-(trifluoromethyl)quinoline (12c) show high potency against SARS-CoV-2. The selectivity index (SI) of compounds 10g and 12c also indicates the significant efficacy compared to the reference drugs.

Synthesis, Characterization, In Vitro Anticancer Potentiality, and Antimicrobial Activities of Novel Peptide-Glycyrrhetinic-Acid-Based Derivatives

Glycyrrhetinic acid (GA) is one of many interesting pentacyclic triterpenoids showing significant anticancer activity by triggering apoptosis in tumor cell lines. This study deals with the design and synthesis of new glycyrrhetinic acid (GA)-amino acid peptides and peptide ester derivatives. The structures of the new derivatives were established through various spectral and microanalytical data. The novel compounds were screened for their in vitro cytotoxic activity. The evaluation results showed that the new peptides produced promising cytotoxic activity against the human breast MCF-7 cancer cell line while comparing to doxorubicin. On the other hand, only compounds 3, 5, and 7 produced potent activity against human colon HCT-116 cancer cell line. The human liver cancer (HepG-2) cell line represented a higher sensitivity to peptide 7 (IC50; 3.30 μg/mL), while it appeared insensitive to the rest of the tested peptides. Furthermore, compounds 1, 3, and 5 exhibited a promising safety profile against human normal skin fibroblasts cell line BJ-1. In order to investigate the mode of action, compound 5 was selected as a representative example to study its in vitro effect against the apoptotic parameters and Bax/BCL-2/p53/caspase-7/caspase-3/tubulin, and DNA fragmentation to investigate beta (TUBb). Additionally, all the new analogues were subjected to antimicrobial assay against a panel of Gram-positive and Gram-negative bacteria and the yeast candida Albicans. All the tested GA analogues 1-8 exhibited more antibacterial effect against Micrococcus Luteus than gentamicin, but they exhibited moderate antimicrobial activity against the tested bacterial and yeast strains. Molecular docking studies were also simulated for compound 5 to give better rationalization and put insight to the features of its structure.

New pyrimidine and pyrazole-based compounds as potential EGFR inhibitors: Synthesis, anticancer, antimicrobial evaluation and computational studies

This study was focused on the synthesis of new pyrimidines 4a,b, 5a,b and pyrazoles 6a, b as ATP mimicking tyrosine kinase inhibitors of the epidermal growth factor receptor (EGFR). The new compounds were assessed as cytotoxic candidates against human breast cancer cells (MCF-7) and hepatocellular carcinoma cells (HepG-2). All the new compounds appeared as more potent cytotoxic agents than erlotinib, while only compound 4a exhibited more potency than 5-flourouracil and 4b analogue was equipotent to it. Accordingly, the kinase suppression effect of 4a and 4b was further evaluated against EGFR^WT, EGFR^L858R and EGFR^T790M. Both pyrimidine analogues 4a and 4b displayed outstanding inhibitory activity against EGFR^WT and its two mutated isoforms EGFR^L858R and EGFR^T790M in comparing to erlotinib and osimertinib as reference drugs. Additionally, all the new analogues were subjected to antimicrobial assay. Interestingly, both 4a and 4b represented the most promising activity of wide spectrum antimicrobial effect against the examined microbes in comparison to gentamycin and ketoconazole as standard drugs. Moreover, docking results proved the good binding interactions of the compounds 4a and 4b with EGFR^WT and EGFR^T790M which were in accordance with the results of the in vitro enzyme assay. Additional in silico ADMET studies were performed for the new derivatives which represented their good oral absorption, good drug-likeness properties and low toxicity risks in human.

Design, Synthesis, Anticancer Evaluation, Enzymatic Assays, and a Molecular Modeling Study of Novel Pyrazole-Indole Hybrids

The molecular hybridization concept has recently emerged as a powerful approach in drug discovery. A series of novel indole derivatives linked to the pyrazole moiety were designed and developed via a molecular hybridization protocol as antitumor agents. The target compounds (5a-j and 7a-e) were prepared by the reaction of 5-aminopyrazoles (1a-e) with N-substituted isatin (4a,b) and 1H-indole-3-carbaldehyde (6), respectively. All products were characterized via several analytical and spectroscopic techniques. Compounds (5a-j and 7a-e) were screened for their cytotoxicity activities in vitro against four human cancer types [human colorectal carcinoma (HCT-116), human breast adenocarcinoma (MCF-7), human liver carcinoma (HepG2), and human lung carcinoma (A549)] using the MTT assay. The obtained results showed that the newly synthesized compounds displayed good-to-excellent antitumor activity. For example, 5-((1H-indol-3-yl)methyleneamino)-N-phenyl-3-(phenylamino)-1H-pyrazole-4-carboxamide (7a) and 5-((1H-indol-3-yl)methyleneamino)-3-(phenylamino)-N-(4-methylphenyl)-1H-pyrazole-4-carboxamide (7b) provided excellent anticancer inhibition performance against the HepG2 cancer cell line with IC₅₀ values of 6.1 ± 1.9 and 7.9 ± 1.9 μM, respectively, compared to the standard reference drug, doxorubicin (IC₅₀ = 24.7 ± 3.2 μM). The two powerful anticancer compounds (7a and 7b) were further subjected to cell cycle analysis and apoptosis investigation in HepG2 using flow cytometry. We have also studied the enzymatic assay of these two compounds against some enzymes, namely, caspase-3, Bcl-2, Bax, and CDK-2. Interestingly, the molecular docking study revealed that compounds 7a and 7b could well embed in the active pocket of the CDK-2 enzyme via different interactions. Overall, the prepared pyrazole-indole hybrids (7a and 7b) can be proposed as strong anticancer candidate drugs against various cancer cell lines.

Novel heterocyclic hybrids of pyrazole targeting dihydrofolate reductase: design, biological evaluation and in silico studies

A novel series of pyrazole analogues including hydrazones, pyrazolo[4,3-c]-pyridazines, pyrazolo[3,4-e][1,2,4]triazine and pyrazolo[3,4-d][1,2,3]triazoles was designed, synthesised and screened for their in vitro antimicrobial and DHFR inhibition activity. Compounds bearing benzenesulphonamide moiety incorporated with 3-methyl-5-oxo-1H-pyrazol-4(5H)-ylidene) hydrazine 3a or 6-amino-7-cyano-3-methyl-5H-pyrazolo[4,3-c]pyridazine 6a revealed excellent and broad spectrum antimicrobial activity comparable to ciprofloxacin and amphotericin B as positive antibiotic and antifungal controls, respectively. Furthermore, these derivatives proved to be the most active DHFR inhibitors with IC₅₀ values 0.11 ± 1.05 and 0.09 ± 0.91 µM, in comparison with methotrexate (IC₅₀ = 0.14 ± 1.25 µM). The in silico studies were done to calculate the drug-likeness and toxicity risk parameters of the newly synthesised derivatives. Additionally, the high potency of the pyrazole derivatives bearing sulphonamide against DHFR was confirmed with molecular docking and might be used as an optimum lead for further modification.

Synthesis and Biological Evaluation of New Pyridothienopyrimidine Derivatives as Antibacterial Agents and Escherichia coli Topoisomerase II Inhibitors

The growing resistance of bacteria to many antibiotics that have been in use for several decades has generated the need to discover new antibacterial agents with structural features qualifying them to overcome the resistance mechanisms. Thus, novel pyridothienopyrimidine derivatives (2a,b-a,b) were synthesized by a series of various reactions, starting with 3-aminothieno[2,3-b]pyridine-2-carboxamides (1a,b). Condensation of compounds 1a,b with cyclohexanone gave 1'H-spiro[cyclohexane-1,2'-pyrido[3',2':4,5]thieno[3,2-d]pyrimidin]-4'(3'H)-ones (2a,b), which in turn were utilized to afford the target 4-substituted derivatives (3a,b-8a,b). In vitro antibacterial activity evaluations of all the new compounds (2a,b-8a,b) were performed against six strains of Gram-negative and Gram-positive bacteria. The target compounds showed significant antibacterial activity, especially against Gram-negative strains. Moreover, the compounds (2a,b; 3a,b; 4a,b; and 5a,b) that exhibited potent activity against Escherichia coli were selected to screen their inhibitory activity against Escherichia coli topoisomerase II (DNA gyrase and topoisomerase IV) enzymes. Compounds 4a and 4b showed potent dual inhibition of the two enzymes with IC₅₀ values of 3.44 µΜ and 5.77 µΜ against DNA gyrase and 14.46 µΜ and 14.89 µΜ against topoisomerase IV, respectively. In addition, docking studies were carried out to give insight into the binding mode of the tested compounds within the E. coli DNA gyrase B active site compared with novobiocin.

Synthesis, Antimicrobial Activity and Molecular Docking of Novel Thiourea Derivatives Tagged with Thiadiazole, Imidazole and Triazine Moieties as Potential DNA Gyrase and Topoisomerase IV Inhibitors

To develop new antimicrobial agents, a series of novel thiourea derivatives incorporated with different moieties 2–13 was designed and synthesized and their biological activities were evaluated. Compounds 7a, 7b and 8 exhibited excellent antimicrobial activity against all Gram-positive and Gram-negative bacteria, and the fungal Aspergillus flavus with minimum inhibitory concentration (MIC) values ranged from 0.95 ± 0.22 to 3.25 ± 1.00 μg/mL. Furthermore, cytotoxicity studies against MCF-7 cells revealed that compounds 7a and 7b were the most potent with IC₅₀ values of 10.17 ± 0.65 and 11.59 ± 0.59 μM, respectively. On the other hand, the tested compounds were less toxic against normal kidney epithelial cell lines (Vero cells). The in vitro enzyme inhibition assay of 8 displayed excellent inhibitory activity against Escherichia coli DNA B gyrase and moderate one against E. coli Topoisomerase IV (IC₅₀ = 0.33 ± 1.25 and 19.72 ± 1.00 µM, respectively) in comparison with novobiocin (IC₅₀ values 0.28 ± 1.45 and 10.65 ± 1.02 µM, respectively). Finally, the molecular docking was done to position compound 8 into the E. coli DNA B and Topoisomerase IV active pockets to explore the probable binding conformation. In summary, compound 8 may serve as a potential dual E. coli DNA B and Topoisomerase IV inhibitor.

Synthesis and molecular docking study of new pyrazole derivatives as potent anti-breast cancer agents targeting VEGFR-2 kinase

Based on the previous studies that revealed the valuable role of pyrazole scaffold in cancer management and VEGFR-2 inhibition, a new set of pyrazole conjugated with pyrazoline, triazolopyrimidine and pyrazolone moieties were synthesized and investigated for their anticancer efficiency against human breast cancer MCF-7. The anticancer screening revealed the significant sensitivity of breast carcinoma towards compounds 4b, 5c, 6c, 7b, 7c and 12c with IC₅₀ values ranging from 16.50 - 26.73 µM in comparison with tamoxifen (IC₅₀ = 23.31 µM). Moreover, the new analogues were further examined for their VEGFR-2 inhibitory activity, among the tested derivatives 5c, 6c, 7b, 7c and 12c displayed prominent inhibitory efficiency versus VEGFR-2 kinase with % inhibition ranging from 70 to 79%. Compounds 6c, 7c and 12c revealed inhibitory efficiency in nanomolar level with IC₅₀ (913.51, 225.17 and 828.23 nM, respectively) comparing to sorafenib (IC₅₀ = 186.54 nM). Flow cytometric analysis revealed that the promising compound 12c prompted pre-G1 apoptosis and cell growth cessation at G2/M phase and stimulated apoptosis via activation of caspase-3. Moreover, molecular docking study of the promising derivatives was performed to highlight their binding modes and interactions with the amino acid residues of VEGFR-2 enzyme.

Antibacterial Evaluation, In Silico Characters and Molecular Docking of Schiff Bases Derived from 5-aminopyrazoles

A series of Schiff bases 14-25 were designed and synthesized for evaluation of their antibacterial properties against multi-drug resistant bacteria (MDRB). The antibacterial activities of Schiff bases 14-25 showed that most of the synthesized compounds displayed a significant antibacterial activity. Assessment of in silico ADMET properties (absorption, distribution, metabolism, excretion and toxicity) of Schiff bases illustrates that all derivatives showed agreement to the Lipinski's rule of five. Further enzymatic assay aided by molecular docking study demonstrated that compound 18 is a potent inhibitor of staphylococcus aureus DNA gyrase and dihydrofolate reductase kinases. This study could be valuable in the discovery of new potent antimicrobial agents.

In vitro anticancer potentiality and molecular modelling study of novel amino acid derivatives based on N1,N3-bis-(1-hydrazinyl-1-oxopropan-2-yl) isophthalamide

A series of N¹,N³-bis (1-oxopropan-2-yl) isophthalamide-based derivatives 4–16 were prepared and their structures were confirmed by different spectral tools. The cytotoxic potentiality of novel compounds 4–16 was assessed by the MTT assay method on colon, lung and breast tumour cell lines. Compound 5 gave the most significant specificity anticancer activity with safety response on normal cell lines. In vitro enzyme assay and several apoptotic parameters were examined to elucidate the mode of action of compound 5. Molecular docking studies also were simulated to put insight and give better understanding to its structural features.

Novel phthalimide based analogues: design, synthesis, biological evaluation, and molecular docking studies

Pyrazolylphthalimide derivative 4 was synthesized and reacted with different reagents to afford the target compounds imidazopyrazoles 5-7, pyrazolopyrimidines 9, 12, 14 and pyrazolotriazines 16, 17 containing phthalimide moiety. The prepared compounds were established by different spectral data and elemental analyses. Additionally, all synthesized derivatives were screened for their antibacterial activity against four types of Gram + ve and Gram-ve strains, and for antifungal activity against two fungi micro-organisms by well diffusion method. Moreover, the antiproliferative activity was tested for all compounds against human liver (HepG-2) cell line in comparison with the reference vinblastine. Moreover, drug-likeness and toxicity risk parameters of the newly synthesized compounds were calculated using in silico studies. The data from structure-actvity relationship (SAR) analysis suggested that phthalimide derivative bearing 3-aminopyrazolone moiety, 4 illustrated the best antimicrobial and antitumor activities and might be considered as a lead for further optimization. To investigate the mechanism of the antimicrobial and anticancer activities, enzymatic assay and molecular docking studies were carried out on E. coli topoisomerase II DNA gyrase B and VEGFR-2 enzymes.

Design, Synthesis, and Molecular Docking Study of Novel Heterocycles Incorporating 1,3,4-Thiadiazole Moiety as Potential Antimicrobial and Anticancer Agents

A new series of 5-(3,5-dinitrophenyl)-1,3,4-thiadiazole derivatives were prepared and evaluated for their in vitro antimicrobial, antitumor, and DHFR inhibition activity. Compounds 9, 10, 13, and 16 showed strong and broad-spectrum antimicrobial activity comparable to Amoxicillin and Fluconazole as positive antibiotic and antifungal controls, respectively. Compounds 6, 14, and 15 exhibited antitumor activity against four human cancer cell lines, CCRF-CEM leukemia, HCT-15 colon, PC-3 prostate, and UACC-257 melanoma cell lines using Doxorubicin as a reference drug. Compounds 10, 13, 14, and 15 proved to be the most active DHFR inhibitors with an IC₅₀ range of 0.04 ± 0.82–1.00 ± 0.85 µM, in comparison with Methotrexate (IC₅₀ = 0.14 ± 1.38 µM). The highly potent DHFR inhibitors shared a similar molecular docking mode and made a critical hydrogen bond and arene‒arene interactions via Ser59 and Phe31 amino acid residues, respectively.

Anticancer evaluation and molecular modeling of multi-targeted kinase inhibitors based pyrido[2,3-d]pyrimidine scaffold

An efficient synthesis of substituted pyrido[2,3-d]pyrimidines was carried out and evaluated for in vitro anticancer activity against five cancer cell lines, namely hepatic cancer (HepG-2), prostate cancer (PC-3), colon cancer (HCT-116), breast cancer (MCF-7), and lung cancer (A-549) cell lines. Regarding HepG-2, PC-3, HCT-116 cancer cell lines, 7-(4-chlorophenyl)-2-(3-methyl-5-oxo-2,3-dihydro-1H-pyrazol-1-yl)-5-(p-tolyl)- pyrido[2,3-d]pyrimidin-4(3H)-one (5a) exhibited strong, more potent anticancer (IC50: 0.3, 6.6 and 7 µM) relative to the standard doxorubicin (IC50: 0.6, 6.8 and 12.8 µM), respectively. Kinase inhibitory assessment of 5a showed promising inhibitory activity against three kinases namely PDGFR β, EGFR, and CDK4/cyclin D1 at two concentrations 50 and 100 µM in single measurements. Further, a molecular docking study for compound 5a was performed to verify the binding mode towards the EGFR and CDK4/cyclin D1 kinases.

Biological Validation of Novel Polysubstituted Pyrazole Candidates with in Vitro Anticancer Activities

With the aim of developing novel antitumor scaffolds, a novel series of polysubstituted pyrazole derivatives linked to different nitrogenous heterocyclic ring systems at the C-4 position were synthesized through different chemical reactions and characterized by means of spectral and elemental analyses and their antiproliferative activity against 60 different human tumor cell lines was validated by the U.S. National Cancer Institute using a two stage process. The in vitro anticancer evaluation revealed that compound 9 showed increased potency toward most human tumor cell lines with GI₅₀MG-MID = 3.59 µM, as compared to the standard drug sorafenib (GI₅₀ MG-MID = 1.90 µM). At the same time, compounds 6a and 7 were selective against the HOP-92 cell line of non-small cell lung cancer with GI₅₀ 1.65 and 1.61 µM, respectively.

Synthesis and anti-inflammatory evaluation of new substituted 1-(3-chlorophenyl)-3-(4-methoxyphenyl)-1H-pyrazole derivatives

A series of heterocyclic derivatives including 1,2,4-triazole-3(4H)-one (3a,b), 1H-pyrazol-5(4H)-one (4,5), 1H-pyrazol-4-carbonitrile (7), pyridine-3-carbonitrile (8, 9a,b), pyrimidine-5-carbonitrile (10a,b), methylpyrimidin-2(1H)-one or thione (11a,b), pyrimidine-5-carboxylate (12a,b), quinazolin-5(6H)-one (13a,b) and indeno [1,2-d] pyrimidin-5-one (14a,b) moieties conjugated with 1,3-disubstituted pyrazole moiety were synthesized on reaction with semicarbazide, thiosemicarbazide, 3-amino-5-oxo-2-pyrazoline, cyanoacetohydrazide, 2-acetyl thiophene, p-chloroacetophenone, urea, thiourea and 1,3-dicarbonyl compounds, respectively, by using 1-(3-chlorophenyl)-3-(4-methoxyphenyl)-1H-pyrazole-4-carboxaldehyde (2) as starting material. The structures of all the newly synthesized products have been established on the basis of analytical and spectral data. The anti-inflammatory screening showed that most of the obtained compounds were found to have significant anti-inflammatory activities with prostaglandin inhibition at a dose level of 2.5 and 5 mg/kg comparable to celecoxib as a reference control. The ulcer indices of all compounds are mainly in the safe level (UI = 2.10-4.27) except for compounds 9a and 14a, which were highly ulcerogenic.