Synthesis, characterization, biological screening and in silico studies of novel pyrazole-chalcone derivatives as potent aromatase inhibitors for breast cancer therapy

In the present study a series new 8-hydroxyquinoline-Benzimidazole hybrids (6a–l) were designed, synthesized (6a–l) by using conventional synthetic methods and assayed for their antimicrobial evaluation. The newly synthesized compounds (6a–l) were screened for their antibacterial activity against four strains i.e., E. coli, S. aureus, P. aeruginosa and B. subtilis and antifungal activity tested against A. niger and C. albicans. The compounds 6b, 6c, 6g, 6h, 6i, 6k and 6l are found to be active against all 4 bacterial strains. The compounds 6a, 6b, 6c, 6g, 6h, 6i, 6k and 6l are showing almost same antifungal activity when compared to the standard drug Voriconazole against A. niger. Whereas, In the case of C. albicans the compounds 6c, 6g, 6h, 6i, 6j, 6k and 6l are showing good antifungal activity. The MIC studies revealed that these compounds were showing the MIC values between 3.9 and 62.5 μg/ml for all the four bacterial strains. Among all the compounds, the compound 6g was showing the 3.9 μg/ml MIC value for E. coli and P. aeruginosa and found to be most potent compound antibacterial agent. From the results of the MIC studies exhibit that these compounds were good antifungal agents and showing the MIC values ranging between 19.2 and 500 μg/ml for both A. niger and C. albicans. The compound 6f was emerged as most potent antifungal agent by exhibiting the 22.3 μg/ml MIC value for A. niger and 19.2 μg/ml MIC value for C. albicans. Thus it is anticipated that these compounds will emerged as potential antibacterial as well antifungal agents on further exploration.

Chalcone derivatives have been proven and documented as non-steroidal anticancer agents. A study of chalcone can be performed as an aromatase inhibitor. One crucial strategy for managing estrogen-positive breast cancer is aromatase inhibition. A total of 13 derivatives of chalcone were synthesized by the aldol condensation reaction and characterized by FTIR, MS, and NMR. Molecular docking was performed by the maestro Schrodinger Suite. In silico ADME study was executed by the QikProp software. All 13 compounds were assessed for the cytotoxicity study in human cancer cell line MCF-7 and are subject to further aromatase inhibition assay on selected chalcone derivatives. Four compounds, 3gA, 3jA, 3kA, and 3lA were found to be more potent chalcone derivatives with their IC50 values of 18.13±1.19 µM, 21.71±1.61 µM, 16.36±1.47 µM and 21.06±1.87 µM, respectively. Using a fluorogenic test kit, the in vitro aromatase inhibitory activity of four drugs (3gA, 3jA, 3kA, and 3lA) was investigated. The values of IC50 for compounds 3gA, 3jA, 3kA, and 3lA were found to be 2.76±0.83 µM, 6.45±3.38 µM, 4.82±1.52 µM and 3.00±1.63 µM, respectively. Lastly, QikProp 4.8 software was used to calculate the ADME parameters (absorption, distribution, metabolism, and excretion) of synthesized compounds. It was concluded that 3gA is the most potent compound having potent aromatase inhibitory activity in comparison to Letrozole with an IC50 value of 2.76±0.83 µM. At the same time, 3jA and 3lA have good aromatase inhibitory activity. Therefore, For the identification of aromatase inhibitory activity, these compounds make good lead compounds for further study as anticancer agents.

Prooxidant augmented therapy is a ROS-based anticancer drug in which a prooxidant compound is linked with an inhibitor of antioxidant enzyme(s). This will lead to an auto-synergistic effect with a consequent intracellular accumulation of ROS. In the current study, 15 new imidazole derivatives (4a-o) were synthesized and assessed as unimolecular auto-augmented prooxidant anticancer agents. The compounds were designed based on incorporating α, β-unsaturated ketones (trans-cinnamaldehyde scaffold) as a thioredoxin reductase enzyme inhibitor, and a prooxidant side chain (R) to the core imidazole scaffold of the recently reported cytotoxic lead compound 2-(5-bromothiophen-2-yl)-4,5-diphenyl-1H-imidazole. The antiproliferative/cytotoxic activity of compounds (4a-o) was assessed against breast adenocarcinoma (MCF-7), hepatocellular carcinoma (HepG2), and colorectal adenocarcinoma (HCT-116) cells using SRB-U assay; IC50's and resistance fractions (R-values) were calculated using Emax mathematical model. HepG2 cells were the most sensitive among other tested tumour cell lines; Compounds 4a, 4c, 4e, 4g, 4i, and 4k showed moderate to high HepG2 cytotoxic/antiproliferative activity with average IC50 of 2.2 µM and the resistant fraction (R-values) did not exceed 30%. In addition, compounds 4a, 4c, 4e, 4g, 4i and 4k significantly increased the total and the intracellular ROS levels within 2 hours of exposure up to 158.2% and 117.7% of normal untreated cells, respectively. The potential apoptotic/necrotic effects of compounds 4a, 4c, 4e, 4g, 4i, and 4k against HepG2 cells were investigated after staining with Annexin V-FITC/PI coupled with flow cytometry. Compound 4e showed the most prominent cell-killing effect by inducing 4 folds apoptosis and 2.5 folds necrosis in HepG2 cells compared to untreated cells. Compounds 4g and 4a showed weaker apoptotic and necrotic effects compared to compound 4e. Furthermore, molecular docking was conducted to assess the interaction between the α, β-unsaturated ketones moiety and x-ray crystal structure of thioredoxin reductase enzyme (pdb: 2J3N) using discovery studio 2.5 Cdocker protocol. Compounds 4a, 4c, 4e and 4 g had a proper 3D arrangement that enables them to fit in FAD-binding the site and perform hydrogen bond with THR 58. In addition, In silico investigation of human intestinal absorption after oral administration for Compounds 4a, 4c, 4e, and 4 g was carried out using Accelrys Discovery studio and revealed possible oral absorption to be confirmed experimentally. In conclusion, the auto-augmented compounds possessing prooxidant ROS generator group and α, β-unsaturated ketones not only elicited tumor cell killing effect via increasing the intracellular ROS level but also showed docking study-based evidence for inhibiting the thioredoxin antioxidant enzyme. Citation Format: Abdel-Sattar M. Omar, Eman M El-labbad, Ahmed M. Al-Abd. Design and synthesis of imidazole derivatives as augmented prooxidant anticancer agents [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 287.

Seven chalcone derivatives were synthesized by the Claisen-Schmidt condensation. The structures of the compounds were confirmed by spectral data (Ultraviolet/visible, infrared, nuclear magnetic resonance and mass spectroscopy). The compounds were tested for their in silico and in vitro antimicrobial and antioxidant activities. The molecular docking assessments showed that all the compounds exhibited good binding affinity with the target microorganism proteins but, compounds 6e and 6g showed better binding affinity compared with the standards. The antimicrobial test revealed that all the compounds screened were active against Staphylococcus aureus and Bacillus subtilis and had minimum inhibitory concentrations (MIC) between 0.4 and 0.6 mg/mL. Compounds 6a, 6c and 6d had moderate activities on Salmonella typhi. Compounds 6b and 6c had moderate activity on Escherichia coli. Compound 6c had moderate activity on Aspergillus niger while compounds 6a and 6e had poor activity. All the compounds except compound 6e had no inhibition against Pseudomonas aeruginosa. The in-vitro antioxidant activity was assessed using ethylenediaminetetraacetate (EDTA) as the standard. Compounds 6c, 6e and 6g gave excellent inhibitory activity better than the standard. Compound 6a gave good activity at 500 μg/mL and 1000 μg/mL concentrations but, below the standard at 250 μg/mL and no inhibition at 125 μg/mL. Compound 6d had good inhibition at 500 μg/mL and 1000 μg/mL but, no inhibition at 125 μg/mL and 250 μg/mL. Compound 6b was found to be inactive in all the concentrations. Absorption, distribution, metabolism and excretion properties of the compounds were assessed using SwissADME. The results of lead likeness showed that compound 6e is a lead-like molecule.

The DNA topoisomerase (topo) II of chloroquine-sensitive and chloroquine-resistant strains of the rodent malaria parasite P. berghei were utilized as a target for testing of antimalarial compounds. Compounds belonging to the bischalcone and chalcone series significantly inhibited enzyme activity and percentage parasitaemia of chloroquine-sensitive and chloroquine-resistant strains of P. berghei. Compounds 1a, 1b, 2a, 2b, and 2c showed 100% inhibition while compounds 2h and 2i showed 60% and 63% inhibition of topoisomerase II activity of the chloroquine-sensitive strain, respectively. Compounds 2a, 2b, and 2d significantly inhibited the topo II activity of chloroquine-resistant strain. Compounds 2g and 2e specifically inhibited the topo II activity of the chloroquine-resistant strain of P. berghei with no effect on the chloroquine-sensitive strain. The in vitro topo II inhibition by chalcone and bischalcone analogs can be correlated with their in vivo antimalarial activity, as compounds 2c and 2h inhibited both in vitro activity of topo II and in vivo parasitaemia of the chloroquine-sensitive strain of P. berghei. In the chloroquine-resistant strain, compounds 2c, 2e, 2g, and 2i inhibited activity against both in vitro topo II and parasitaemia in vivo. The significant inhibition of topo II in the chloroquine-resistant strain by some of the analogs suggests the utilization of these structures for the synthesis of compounds active against chloroquine-resistant malarial parasites.

In this work, a series of curcumin derivatives (1a-1h, 2a-2g, and 3a-3c) were synthesized for the suppression of castration-resistant prostate cancer cells. All synthesized compounds were characterized by 1H NMR, 13C NMR, HRMS, and melting point. The invitro cytotoxicity study shows that compounds 1a, 1e, 1f, 1h, 2g, 3a, and 3c display similar or enhanced cytotoxicity against 22Rv1 and C4-2 cells as compared to ASC-J9, other synthesized compounds display reduced cytotoxicity against 22Rv1 and C4-2 cells as compared to ASC-J9. Molecular docking simulation was performed to study the binding affinity and probable binding modes of the synthesized compounds with androgen receptor. The results show that all synthesized compounds exhibit higher cdocker interaction energies as compared to ASC-J9. Compounds 1h, 2g, and 3c not only show strong cytotoxicity against 22Rv1 and C4-2 cells but also exhibit high binding affinity with androgen receptor. In androgen receptor suppression study, compounds 1f and 2g show similar androgen receptor suppression effect as compared to ASC-J9 on C4-2 cells, compound 3c displays significantly enhanced AR suppression effect as compared to ASC-J9, 1f and 2g. Compounds 1a, 1e, 1f, 1h, 2g, 3a and 3c prepared in this work have significant potential for castration-resistant prostate cancer therapy.

Background: Structural similarity in Chalcone and Pyrazoline brought our intention for the analysis of such compounds. This study involved the synthesis of chalcones and their pyrazoline derivatives and their screening as cholinesterase inhibitors. The newly synthesized compounds were also investigated for their antioxidant potential. </P><P> Methods: Chalcones were synthesized by well-established methods of synthesis and their structural elucidation was carried out by H-NMR, 13C-NMR, Mass spectrometry and FTIR. For the determination of inhibition potency of synthesized compounds, spectrophotometric method was applied whereas, DPPH free radical scavenging method was used to check the antioxidant ability. </P><P> Results: Chalcones and their pyrazoline derivatives were synthesized and characterised by 1HNMR, 13C-NMR, Mass spectrometry and FTIR. The compounds were screened for their anti- Alzheimer activity, which exhibited that compounds 1g, 1c and 1h, 1g showed strong inhibitory potency against acetylcholinesterase and butyrylcholinesterase, respectively. DPPH radical scavenging method was applied to check anti-oxidant potential of synthesized compounds and results explored that among all the synthesized compounds only compounds 1c and 1b showed strong scavenging potential. </P><P> Conclusion: Chalcone and their pyrazoline derivatives were synthesized and screened for their anti-Alzheimer and antioxidant potential. The experimental results of anti-Alzheimer activity were compared with molecular docking studies, which showed that compounds 1g, 1c and 1h, 1g were active against AChE and BChE, respectively. Among the synthesized compounds 1c and 1b were found to be most potent antioxidants. These results suggest that compound 1b, 1c, 1g and 1h may further be explored for further developments.

A novel series of benzimidazole ureas 3a–h were elaborated using 2-(1H-benzoimidazol-2-yl) aniline 1 and the appropriate isocyanates 2a–h. The antioxidant and possible antidiabetic activities of the target benzimidazole-ureas 3a–h were evaluated. Almost all compounds 3a–h displayed strong to moderate antioxidant activities. When tested using the three antioxidant techniques, TAC, FRAP, and MCA, compounds 3b and 3c exhibited marked activity. The most active antioxidant compound in this family was compound 3g, which had excellent activity using four different methods: TAC, FRAP, DPPH-SA, and MCA. In vitro antidiabetic assays against α-amylase and α-glucosidase enzymes revealed that the majority of the compounds tested had good to moderate activity. The most favorable results were obtained with compounds 3c, 3e, and 3g, and analysis revealed that compounds 3c (IC50 = 18.65 ± 0.23 μM), 3e (IC50 = 20.7 ± 0.06 μM), and 3g (IC50 = 22.33 ± 0.12 μM) had good α-amylase inhibitory potential comparable to standard acarbose (IC50 = 14.21 ± 0.06 μM). Furthermore, the inhibitory effect of 3c (IC50 = 17.47 ± 0.03 μM), 3e (IC50 = 21.97 ± 0.19 μM), and 3g (IC50 = 23.01 ± 0.12 μM) on α-glucosidase was also comparable to acarbose (IC50 = 15.41 ± 0.32 μM). According to in silico molecular docking studies, compounds 3a–h had considerable affinity for the active sites of human lysosomal acid α-glucosidase (HLAG) and pancreatic α-amylase (HPA), indicating that the majority of the examined compounds had potential anti-hyperglycemic action.

A novel series of silibinin and 2,3-dehydrosilybin derivatives bearing carbamate groups were designed, synthesized and their in vitro anticancer activities were screened against human cancer cell lines including MCF-7, NCI-H1299, HepG2 and HT29 by CCK-8 assay. The results showed that most of the compounds significantly suppressed the proliferation of tested cancer cells. Among them, compounds 2h, 3h and 3f demonstrated markedly higher antiproliferative activity on MCF-7 cells with IC50 values of 2.08, 5.54 and 6.84 µM, respectively. Compounds 3e, 3g and 2g displayed better cytotoxic activity against NCI-H1299 cells with IC50 values of 8.07, 8.45 and 9.09 µM, respectively. Compounds 3g, 3c and 3h exhibited a promising inhibitory effect against HepG2 cells with IC50 values of 8.88, 9.47 and 9.99 µM, respectively. Compounds 3e, 2e and 3c revealed effective biological potency on HT29 cells with IC50 values of 6.27, 9.13 and 9.32 µM, respectively. In addition, the outcomes of the docking studies between compounds 2f, 2h, 3e, 3g and Hsp90 receptor (PDB ID: 4AWO) suggest the possible mechanism of inhibition against MCF-7 cell lines. Graphical abstract

Novel sulphonamide-azaheterocycle conjugates and their anti-cancer, anti-inflammatory, anti-diabetic, anti-angiogenesis activity and molecular docking studies

A series of novel piperazine based cinnamic acid bearing coumarin derivatives were designed and synthesized by piperazine based cinnamic acids esterification with 4-hydroxycoumarin and characterized by various spectral techniques like infrared, 1 H nuclear magnetic resonance (NMR), 13 C NMR, and mass. The novel bioactive compounds (7a-7m) screen their potential against different bacterial and fungal strains. Compound 7g (minimum inhibitory concentration [MIC] = 12.5 µg/ml) exhibited potent antibacterial activity against Escherichia colistrain. Compounds 7d, 7f, 7g, 7k, 7l, and 7m showed potent antibacterial activity against all bacterial strains. Compounds 7a, 7g, 7h, 7k, 7l, and 7m exhibited potent antifungal activity against all fungal strains. Furthermore, a molecular docking study revealed that compounds 7d, 7f, 7g, and 7k could bind to the active site of E. coli DNA gyrase subunit B protein and form hydrogen bonding with crucial amino acid residues Arg136 in the active sites. Comprehensively, our study recommends that 7d, 7f, 7g, and 7k could be a promising lead for developing more efficient antimicrobial drug candidates and DNA gyrase inhibitors.

A new series of pyrazolo[1,2-b]phthalazine derivatives (4a–p) bearing the 5-aryloxypyrazole nucleus was synthesized by one-pot, three-component, base-catalyzed cyclo condensation reaction of 3-methyl-5-aryloxy-1-aryl-1H-pyrazole-4-carbaldehyde (1a–d), malononitrile or ethyl cyanoacetate (2a–b) and 2,3-dihydro-1,4-phthalazinedione (3a–b) in ethanol containing an eco friendly base, NaOH, in good to excellent yields. All synthesized compounds (4a–p) were duly characterized by physico-chemical parameters, 1H NMR, 13C NMR, FT-IR and LCMS techniques. In vitro antimicrobial activity of the synthesized compounds was investigated against a representative panel of pathogenic strains. Compounds 4e, 4g, 4h, 4k and 4o exhibited excellent antimicrobial activity compared with first line drugs. In vitro antituberculosis activity was evaluated against Mycobacterium tuberculosis H37Rv, and compounds 4g and 4o emerged as the promising antimicrobial members with better antituberculosis activity. A brine shrimp bioassay was carried out to study the in vitro cytotoxic properties of the synthesized compounds. In vitro antioxidant activity was evaluated by the ferric-reducing antioxidant power method. Compounds 4c, 4d, 4g and 4h showed the highest antioxidant potencies.

This study focused on the design and synthesis of a novel series of 5-ethylsulfonyl-indazole-3-carboxamides (8a–l) as dual inhibitors of VEGFR-2 and EGFR. Compounds 8g and 8h emerged as the most efficient derivatives among all evaluated compounds against breast (MCF-7) and colorectal (HCT-116) cancer cell lines, exhibiting IC50 values of 24 and 28 nM for HCT-116 and MCF-7 cell lines, respectively, for 8g, and 23 and 25 nM for the same cell lines for 8h. Compounds 8g and 8h exhibited a promising safety margin against normal cells (WI-38) (IC50 values > 150 nM). In vitro enzyme assays demonstrated that compounds 8g and 8h exhibited potent inhibition of VEGFR-2 and EGFR. Furthermore, compounds 8g and 8h induced apoptosis by activating Bax, p53, caspase-3, 8, and 9, as well as down-regulating Bcl-2. Compounds 8g and 8h reduced TNF-α and IL-6 levels compared to dexamethasone. The computational investigation of compound 8h, a novel indazole-based urea derivative, was undertaken to rationalize its potent dual inhibition of EGFR and VEGFR-2. Molecular docking studies revealed a high binding affinity and a favorable interaction profile with key kinase residues, particularly hinge-region contacts with Met769 (EGFR) and Glu885/Asp1046 (VEGFR-2). Follow-up molecular dynamics (MD) simulations confirmed the stability of the 8h–EGFR complex over 150 ns, characterized by persistent hydrogen bonding, low RMSF in the binding site, and consistent radius of gyration. Quantum mechanical (QM) analyses, including DFT and MEP mapping, revealed a HOMO–LUMO gap of 4.55 eV, high dipole moment (9.3 D), and distinct electron-rich/hydrogen-bonding regions, supporting strong molecular interactions. Additionally, SwissADME profiling demonstrated acceptable drug-likeness, moderate solubility, and a low CYP-inhibition profile, suggesting favorable pharmacokinetics compared to the reference inhibitor erlotinib. These integrated computational findings align with experimental data on antiproliferative effects and kinase inhibition, reinforcing compound 8h as a promising dual-target anticancer candidate.

Herein, a novel series of naphthamide derivatives has been rationally developed, synthesized, and evaluated for their inhibitory activity against monoamine oxidase (MAO) and cholinesterase (ChE) enzymes. Compared to the reported naphthalene-based hit IV, the new naphthamide hybrids 2a, 2c, 2g and 2h exhibited promising MAO inhibitory activities; with an IC50 value of 0.294μM, compound 2c most potently inhibited MAO-A, while compound 2g exhibited most potent MAO-B inhibitory activity with an IC50 value of 0.519μM. Compounds 2c and 2g showed selectivity index (SI) values of 6.02 for MAO-A and 2.94 for MAO-B, respectively. On the other hand, most compounds showed weak inhibitory activity against ChEs except 2a and 2h over butyrylcholinesterase (BChE). The most potent compounds 2c and 2g were found to be competitive and reversible MAO inhibitors based on kinetic and reversibility studies. Plausible interpretations of the observed biological effects were provided through molecular docking simulations. The drug-likeness predicted by SwissADME and Osiris property explorer showed that the most potent compounds (2a, 2c, 2g, and 2h) obey Lipinski's rule of five. Accordingly, in the context of neurological disorders, hybrids 2c and 2g may contribute to the identification of safe and potent therapeutic approaches in the near future.

The antibiotic resistance and biofilm formation by bacterial pathogens has led to failure in infections elimination. This study aimed to assess the antibacterial and anti-biofilm properties of novel synthesized nitroimidazole compounds (8a–8o). In this study, nitroimidazole compounds were synthesized via the A3 coupling reaction of sample substrates in the presence of copper-doped silica cuprous sulfate (CDSCS). Fifteen and two carbapenemase producing Escherichia coli and Klebsiella pneumonia (CP-E. coli and CP-K. pneumonia, respectively) and one methicillin-resistant Staphylococcus aureus (MRSA) and one methicillin-susceptible S. aureus (MSSA) plus standard strain of each isolate were included. The antibacterial effects of these compounds demonstrated that the lowest minimum inhibitory and bactericidal concentrations (MIC/MBC, respectively) levels corresponded to compound 8g against S. aureus (1/2 µg/mL) and K. pneumonia (8/32 µg/mL) standard and clinical strains and confirmed by in silico assessment. This was comparable to those of metronidazole being 32–128 µg/mL against K. pneumonia and 32–64 µg/mL against S. aureus. In comparison to metronidazole, against CP-E. coli, compounds 8i and 8m had significantly higher antibacterial effects (p < 0.001) and against CP-K. pneumonia, compounds 8a–8j and 8l–8o had significantly higher (p < 0.0001) antibacterial effects. Compound 8g exhibited significantly higher antibacterial effects against MSSA and compounds 8b (p < 0.001), 8c (p < 0.001), 8d (p < 0.001), 8e (p < 0.001) and 8g (p < 0.0001) exerted significantly higher antibacterial effects than metronidazole against MRSA. Moreover, potential anti-biofilm effects was corresponded to compounds 8a, 8b, 8c, 8e, 8f, 8g, 8i, 8k, 8m and 8n. Considering the antibacterial and anti-biofilm effects of novel synthesized compounds evaluated in this study, further assessments is warranted to verify their properties in vivo and clinical trials in the future.