Discovery of novel thiazole derivatives containing pyrazole scaffold as PPAR-γ Agonists, α-Glucosidase, α-Amylase and COX-2 inhibitors; Design, synthesis and in silico study.

A novel series of thiazole derivatives with pyrazole scaffold 16a-l as hybrid rosiglitazone/celecoxib analogs was designed, synthesized and tested for its PPAR-γ activation, α-glucosidase, α-amylase and COX-2 inhibitory activities. Regarding the anti-diabetic activity, all compounds were assessed in vitro against PPAR-γ activation, α-glucosidase and α-amylase inhibition in addition to in vivo hypoglycemic activity (one day and 15 days studies). Compounds 16b, 16c, 16e and 16 k showed good PPAR-γ activation (activation % ≈ 72-79 %) compared to that of the reference drug rosiglitazone (74 %). In addition, the same derivatives 16b, 16c, 16e and 16 k showed the highest inhibitory activities against α-glucosidase (IC50 = 0.158, 0.314, 0.305, 0.128 µM, respectively) and against α-amylase (IC50 = 32.46, 23.21, 7.74, 35.85 µM, respectively) compared to the reference drug acarbose (IC50 = 0.161 and 31.46 µM for α-glucosidase and α-amylase, respectively). The most active derivatives 16b, 16c, 16e and 16 k also revealed good in vivo hypoglycemic effect comparable to that of rosiglitazone. In addition, compounds 16b and 16c had the best COX-2 selectivity index (S.I. = 18.7, 31.7, respectively) compared to celecoxib (S.I. = 10.3). In vivo anti-inflammatory activity of the target derivatives 16b, 16c, 16e and 16 k supported the results of in vitro screening as the derivatives 16b and 16c (ED50 = 8.2 and 24 mg/kg, respectively) were more potent than celecoxib (ED50 = 30 mg/kg). In silico docking, ADME, toxicity, and molecular dynamic studies were carried out to explain the interactions of the most active anti-diabetic and anti-inflammatory compounds 16b, 16c, 16e and 16 k with the target enzymes in addition to their physiochemical parameters.

Design, synthesis and cytotoxic evaluation of new thieno[2,3-d]pyrimidine analogues as VEGFR-2/AKT dual inhibitors, apoptosis and autophagy inducers.

Novel thieno[2,3-d]pyrimidine analogues were designed, synthesized and evaluated for anti-proliferative activity against HepG-2, PC-3 and MCF-7 cancer cell lines. In addition, WI-38 normal cell line was used to explore the safety of all the tested compounds. Compounds 2 (IC50 = 4.29 µM HePG-2, 10.84 µM MCF-7), 6 (IC50 = 14.86 µM HePG-2, 8.04 µM PC-3 and 12.90 µM MCF-7) and 17 (IC50 = 9.98 µM HePG-2, 33.66 µM PC-3 and 14.62 µM MCF-7) were the most promising candidates on the tested cancer cells with high selective toxicity-sparing normal cells. A further mechanistic evaluation revealed promising kinase inhibitory activity, where compound 2 inhibited VEGFR-2 and AKT at IC50 = 0.161 and 1.06 µM, respectively, Furthermore, derivative 6 inhibited VEGFR-2 and AKT at IC50 = 0.487 and 0.364 µM, respectively, while compound 17 showed IC50 = 0.164 and 0.452 µM, respectively. Moreover, compounds 2, 6 resulted in G1 phase cell cycle arrest while candidate 17 arrest cell cycle at G2/M phase. Similar to the apoptosis results, compound 17 showed the highest autophagic induction among the evaluated derivatives. Finally, docking studies were conducted to assess the binding patterns of these active derivatives. The results showed that the binding patterns inside the active sites of both the VEGFR-2 and AKT-1 (allosteric pocket) crystal structures were identical to the reference ligands.

Design, synthesis, antineoplastic activity of new pyrazolo[3,4-d]pyrimidine derivatives as dual CDK2/GSK3ß kinase inhibitors; molecular docking study, and ADME prediction.

In the current study, novel pyrazolo[3,4-d]pyrimidine derivatives 5a-h were designed and synthesized as targeted anti-cancer agents through dual CDK2/GSK-3ß inhibition. The designed compounds demonstrated moderate to potent activity on the evaluated cancer cell lines (MCF-7 and T-47D). Compounds 5c and 5 g showed the most promising cytotoxic activity against the tested cell lines surpassing that of the used reference standard; staurosporine. On the other hand, both compounds showed good safety and tolerability on normal fibroblast cell line (MCR5). The final compounds 5c and 5 g showed a promising dual CDK2/GSK-3ß inhibitory activity with IC50 of 0.244 and 0.128 µM, respectively, against CDK2, and IC50 of 0.317 and 0.160 µM, respectively, against GSK-3ß. Investigating the effect of compounds 5c and 5 g on CDK2 and GSK-3ß downstream cascades showed that they reduced the relative cellular content of phosphorylated RB1 and ß-catenin compared to that in the untreated MCF-7 cells. Moreover, compounds 5c and 5 g showed a reasonable selective inhibition against the target kinases CDK2/GSK-3ß in comparison to a set of seven off-target kinases. Furthermore, the most potent compound 5 g caused cell cycle arrest at the S phase in MCF-7 cells preventing the cells' progression to G2/M phase inducing cell apoptosis. Molecular docking studies showed that the final pyrazolo[3,4-d]pyrimidine derivatives have analogous binding modes in the target kinases interacting with the hinge region key amino acids. Molecular dynamics simulations confirmed the predicted binding mode by molecular docking. Moreover, in silico predictions indicated their favorable physicochemical and pharmacokinetic properties in addition to their promising cytotoxic activity.

Vicinal diaryl pyrazole with tetrazole/urea scaffolds as selective angiotensin converting enzyme-1/cyclooxygenase-2 inhibitors: Design, synthesis, anti-hypertensive, anti-fibrotic, and anti-inflammatory.

As a hybrid weapon, two novel series of pyrazoles, 16a-f and 17a-f, targeting both COX-2 and ACE-1-N-domain, were created and their anti-inflammatory, anti-hypertensive, and anti-fibrotic properties were evaluated. In vitro, 17b and 17f showed COX-2 selectivity (SI = 534.22 and 491.90, respectively) compared to celecoxib (SI = 326.66) and NF-κB (IC50 1.87 and 2.03 µM, respectively). 17b (IC50 0.078 µM) and 17 f (IC50 0.094 µM) inhibited ACE-1 comparable to perindopril (PER) (IC50 0.048 µM). In vivo, 17b decreased systolic blood pressure by 18.6%, 17b and 17f increased serum NO levels by 345.8%, and 183.2%, respectively, increased eNOS expression by 0.97 and 0.52 folds, respectively and reduced NF-κB-p65 and P38-MAPK expression by -0.62, -0.22, -0.53, and -0.24 folds, respectively compared to  l-NAME (-0.34, -0.45 folds decline in NF-κB-p65 and P38-MAPK, respectively). 17b reduced ANG-II expression which significantly reversed the cardiac histological changes induced by L-NAME.

Discovery of novel pyrazole based Urea/Thiourea derivatives as multiple targeting VEGFR-2, EGFRWT, EGFRT790M tyrosine kinases and COX-2 Inhibitors, with anti-cancer and anti-inflammatory activities.

A novel series of pyrazole derivatives with urea/thiourea scaffolds 16a-l as hybrid sorafenib/erlotinib/celecoxib analogs was designed, synthesized and tested for its VEGFR-2, EGFRWT, EGFRT790M tyrosine kinases and COX-2, pro-inflammatory cytokines TNF-α and IL-6 inhibitory activities. All the tested compounds showed excellent COX-2 selectivity index in range of 18.04-47.87 compared to celecoxib (S.I. = 26.17) and TNF-α and IL-6 inhibitory activities (IC50 = 5.0-7.50, 6.23-8.93 respectively, compared to celecoxib IC50 = 8.40 and 8.50, respectively). Screening was carried out against 60 human cancer cell lines by National Cancer Institute (NCI), compounds 16a, 16c, 16d and 16 g were the most potent inhibitors with GI% ranges of 100 %, 99.63-87.02 %, 98.98-43.10 % and 98.68-23.62 % respectively, and with GI50 values of 1.76-15.50 µM, 1.60-5.38 µM, 1.68-7.39 µM and 1.81-11.0 µM respectively, in addition, of showing good safety profile against normal cell line (F180). Moreover, compounds 16a, 16c, 16d and 16 g had cell cycle arrest at G2/M phase with induced necrotic percentage compared to sorafenib of 2.06 %, 2.47 %, 1.57 %, 0.88 % and 1.83 % respectively. Amusingly, compounds 16a, 16c, 16d and 16 g inhibited VEGFR-2 with IC50 of 25 nM, 52 nM, 324 nM and 110 nM respectively, compared to sorafenib (IC50 = 85 nM), and had excellent EGFRWT and EGFRT790M kinase inhibitory activities (IC50 = 94 nM, 128 nM, 160 nM, 297 nM), (10 nM, 25 nM, 36 nM and 48 nM) respectively, compared to both erlotinib and osimertinib (IC50 = 114 nM, 56 nM) and (70 nM, 37 nM) respectively and showed (EGFRwt/EGFRT790M S.I.) of (range: 4.44-9.40) compared to erlotinib (2.03) and osmertinib (1.89).

New 1,2,3-triazole/1,2,4-triazole hybrids linked to oxime moiety as nitric oxide donor selective COX-2, aromatase, B-RAFV600E and EGFR inhibitors celecoxib analogs: design, synthesis, anti-inflammatory/anti-proliferative activities, apoptosis and molecular modeling study.

A new series of bis-triazole 19a-l was synthesised for the purpose of being hybrid molecules with both anti-inflammatory and anti-cancer activities and assessed for cell cycle arrest, NO release. Compounds 19c, 19f, 19h, 19 l exhibited COX-2 selectivity indexes in the range of 18.48 to 49.38 compared to celecoxib S.I. = 21.10), inhibit MCF-7 with IC50 = 9-16 µM compared to tamoxifen (IC50 = 27.9 µM). and showed good inhibitory activity against HEP-3B with IC50 = 4.5-14 µM compared to sorafenib (IC50 = 3.5 µM) (HEP-3B). Moreover, derivatives 19e, 19j, 19k, 19 l inhibit HCT-116 with IC50 = 5.3-13.7 µM compared to 5-FU with IC50 = 4.8 µM (HCT-116). Compounds 19c, 19f, 19h, 19 l showed excellent inhibitory activity against A549 with IC50 = 3-4.5 µM compared to 5-FU with IC50 = 6 µM (A549). Compounds 19c, 19f, 19h, 19 l inhibit aromatase (IC50 of 22.40, 23.20, 22.70, 30.30 µM), EGFR (IC50 of 0.112, 0.205, 0.169 and 0.066 µM) and B-RAFV600E (IC50 of 0.09, 0.06, 0.07 and 0.05 µM).

New pyrazolyl-thiazolidinone/thiazole derivatives as celecoxib/dasatinib analogues with selective COX-2, HER-2 and EGFR inhibitory effects: design, synthesis, anti-inflammatory/anti-proliferative activities, apoptosis, molecular modelling and ADME studies.

Two new series of pyrazolyl-thiazolidinone/thiazole derivatives 16a-b and 18a-j were synthesised, merging the scaffolds of celecoxib and dasatinib. Compounds 16a, 16b and 18f inhibit COX-2 with S.I. 134.6, 26.08 and 42.13 respectively (celecoxib S.I. = 24.09). Compounds 16a, 16b, 18c, 18d and 18f inhibit MCF-7 with IC50 = 0.73-6.25 µM (dasatinib IC50 = 7.99 µM) and (doxorubicin IC50 = 3.1 µM) and inhibit A549 with IC50 = 1.64-14.3 µM (dasatinib IC50 = 11.8 µM and doxorubicin IC50 = 2.42 µM) with S.I. (F180/MCF7) of 33.15, 7.13, 18.72, 13.25 and 8.28 respectively higher than dasatinib (4.03) and doxorubicin (3.02) and S.I. (F180/A549) of 14.75, 12.96, 4.16, 7.07 and 18.88 respectively higher than that of dasatinib (S.I. = 2.72) and doxorubicin (S.I = 3.88). Derivatives 16a, 18c, 18d, 18f inhibit EGFR and HER-2 IC50 for EGFR of 0.043, 0.226, 0.388, 0.19 µM respectively and for HER-2 of 0.032, 0.144, 0.195, 0.201 µM respectively.

Design, synthesis and mechanistic study of new benzenesulfonamide derivatives as anticancer and antimicrobial agents via carbonic anhydrase IX inhibition.

Changes in gene expression cause uncontrolled cell proliferation and consequently tumor hypoxia. The tumor cells shift their metabolism to anaerobic glycolysis with a significant modification in pH. Therefore, an over expression of carbonic anhydrase IX (CA IX) genes was detected in many solid tumors. Accordingly, selective inhibition of CA IX can be a useful target for discovering novel antiproliferative agents. The present study described the synthesis of new aryl thiazolone-benzenesulfonamides 4a-j as well as their carbonic anhydrase IX inhibitory effect. All the designed derivatives were evaluated for their anti-proliferative activity against triple-negative breast cancer cell line (as MDA-MB-231) and another breast cancer cell line (MCF-7) in addition to normal breast cell line MCF-10A. Compounds 4b-c, 4e, 4g-h showed significant inhibitory effect against both cancer cell lines at concentration ranges from 1.52-6.31 µM, with a high selectivity against breast cancer cell lines ranges from 5.5 to 17.5 times. Moreover, three sulfonamides derivatives 4e, 4g and 4h showed excellent enzyme inhibition against CA IX with IC50 10.93-25.06 nM and against CA II with IC50 1.55-3.92 µM that revealed their remarkable selectivity for CA IX over CA II. Additionally, 4e was able to induce apoptosis in MDA-MB-231 with a significant increase in the annexin V-FITC percent by 22 fold as compared with control. Cellular uptake on MDA-MB-231 cell lines were carried out using HPLC method on the three active compounds (4e, 4g and 4h). On the other hand inhibition of one or more CAs present in bacteria was reported to interfere with bacterial growth. So, the new benzenesulfonamides were evaluated against their antibacterial and anti-biofilm activities. Analogues 4e, 4g and 4h exhibited significant inhibition at 50 µg mL-1 concentration with 80.69%, 69.74% and 68.30% against S. aureus compared to the positive control CIP which was 99.2%, while compounds 4g and 4h showed potential anti-biofilm inhibition 79.46% and 77.52% against K. pneumonia. Furthermore, the designed compounds were docked into CA IX (human) protein (PDB ID: 5FL6) and molecular modeling studies revealed favorable binding interactions for the active inhibitors. Finally, the predictive ADMET studies showed that, compounds 4e, 4g and 4h possessed promising pharmacokinetic properties.

Design, synthesis and antiproliferative evaluation of new tricyclic fused thiazolopyrimidines targeting topoisomerase II: Molecular docking and apoptosis inducing activity.

A novel series of thiazolopyrimidines and fused thiazolopyrimidines was designed and synthesized as topoisomerase II alpha inhibitors. All synthesized compounds were screened by the National Cancer Institute (NCI), Bethesda, USA for anticancer activity against 60 human cancer cell lines representing the following cancer types: leukemia, non-small cell lung, colon, CNS, melanoma, ovarian, renal, prostate, and breast cancers. Compound 3a was found to be the most potent inhibitor on renal cell line (A-498) causing 83.03% inhibition (IC50 = 1.89 µM). DNA-flow cytometric analysis showed that compound 3a induce cell cycle arrest at G2/M phase leading to cell proliferation inhibition and apoptosis. Moreover, fused thiazolopyrimidines 3a showed potent topoisomerase II inhibitory activity (IC50 = 3.19 µM) when compared with reference compound doxorubicin (IC50 = 2.67 µM). Docking study of all the synthesized compounds showed that compound 3a interacts in a similar pattern to etoposide and stabilizing the topoisomerase cleavage complex (Top2-cc) that accounts for its high potency.

New fused pyrimidine derivatives with anticancer activity: Synthesis, topoisomerase II inhibition, apoptotic inducing activity and molecular modeling study.

A new series of triazolopyrimidines and thiazolopyrimidine hydrobromides was designed and prepared as topoisomerase II inhibitors. Screening of all synthesized compounds was carried out by the National Cancer Institute (NCI) of USA. Activity against 60 human cancer cell lines representing different cancer types was determined. Accordingly, compound 3d was the most potent inhibitor especially against the renal cell line A498 causing 92.46% inhibition (IC50 = 3.5 µM). Moreover, cell cycle analysis showed cell cycle arrest caused by compound 3d at the G2/M phase leading to cell proliferation inhibition and pro-apoptotic activity. Also, thiazolopyrimidine 3d showed potent topoisomerase II inhibitory activity (IC50 2.89 µM) compared to doxorubicin which was used as a reference compound with (IC50 2.67 µM). Moreover, molecular modeling study of the synthesized compounds was performed and revealed the binding interactions of compound 3d in the binding site of topoisomerase II enzyme rationalizing the significant inhibitory activity of this derivative.

Design, synthesis and biological evaluation of new 2-aminothiazole scaffolds as phosphodiesterase type 5 regulators and COX-1/COX-2 inhibitors.

A new series of 2-aminothiazole derivatives was designed and prepared as phosphodiesterase type 5 (PDE5) regulators and COX-1/COX-2 inhibitors. The screening of the synthesized compounds for PDE5 activity was carried out using sildenafil as a reference drug. Strikingly, compounds 23a and 23c were found to have a complete inhibitory effect on PDE5 (100%) at 10 µM without causing hypotension and the limited side effect of PDE5 inhibitors, suggest a distinctive therapeutic role of these derivatives in erectile dysfunction. On the other hand, compounds 5a, 17, 21 and 23b increased the PDE5 activity (PDE5 enhancers) at 10 µM. In addition, the study includes the screening of the COX-1/COX-2 inhibition induced by the synthesized compounds. All tested compounds have an inhibitory effect against COX-1 activity (IC50 = 1.00-6.34 µM range) and COX-2 activity (IC50 = 0.09-0.71 µM range). Moreover, a molecular docking study was implemented to reveal the binding interactions of potent compounds in the binding sites of PDE5 (PDB ID 2H42), COX-1 and COX-2 (PDB ID 3LN1) enzymes. For the interaction with the PDE5 enzyme, activator compounds had a strong binding mode (HB with Gln817:A) than inhibitory derivatives. Both types of compounds are considered as PDE5 regulators. This novel finding will encourage us to discover a new pharmacological application of small chemical entities as the PDE5 enhancer, or will lower side effects as PDE5 inhibitors. All active compounds adopted the Y-shape along the COX-2 active site.

Interaction of small molecules with polynucleotide repeats and frameshift site RNA.

This mini-review describes the interaction between small molecules and RNA, in addition to its application either in treating RNA-associated diseases or detecting target molecules. In the case of RNA-associated disease treatment, the designed small molecules interact with RNA sites, forming adducts and providing successful therapeutic strategies over oligonucleotides. On the other hand, synthetically designed RNA moieties (aptamers) interact with target molecules like toxins, drugs, hormones; these interactions are useful in the detection, quantification or separation of these target moieties.