The effect of novel synthetic semicarbazone- and thiosemicarbazone-linked 1,2,3-triazoles on the apoptotic markers, VEGFR-2, and cell cycle of myeloid leukemia

Fluorinated indeno-quinoxaline bearing thiazole moieties as hypoglycaemic agents targeting α-amylase, and α-glucosidase: synthesis, molecular docking, and ADMET studies

Inhibition of α-glucosidase and α-amylase are key tactics for managing blood glucose levels. Currently, stronger, and more accessible inhibitors are needed to treat diabetes. Indeno[1,2-b] quinoxalines-carrying thiazole hybrids 1-17 were created and described using NMR. All analogues were tested for hypoglycaemic effect against STZ-induced diabetes in mice. Compounds 4, 6, 8, and 16 were the most potent among the synthesised analogues. These hybrids were examined for their effects on plasma insulin, urea, creatinine, GSH, MDA, ALT, AST, and total cholesterol. Moreover, these compounds were tested against α-glucosidase and α-amylase enzymes in vitro. The four hybrids 4, 6, 8, and 16 represented moderate to potent activity with IC50 values 0.982 ± 0.04, to 10.19 ± 0.21 for α-glucosidase inhibition and 17.58 ± 0.74 to 121.6 ± 5.14 μM for α-amylase inhibition when compared to the standard medication acarbose with IC50=0.316 ± 0.02 μM for α-glucosidase inhibition and 31.56 ± 1.33 μM for α-amylase inhibition. Docking studies as well as in silico ADMT were done.

Novel imidazolone derivatives as potential dual inhibitors of checkpoint kinases 1 and 2: Design, synthesis, cytotoxicity evaluation, and mechanistic insights

Applying various drug design strategies including ring variation, substituents variation, and ring fusion, two series of 2-(alkylthio)-5-(arylidene/heteroarylidene)imidazolones and imidazo[1,2-a]thieno[2,3-d]pyrimidines were designed and prepared as dual potential Chk1 and Chk2 inhibitors. The newly synthesized hybrids were screened in NCI 60 cell line panel where the most active derivatives 4b, d-f, and 6a were further estimated for their five dose antiproliferative activity against the most sensitive tumor cells including breast MCF-7 and MDA-MB-468 and non-small cell lung cancer EKVX as well as normal WI-38 cell. Noticeably, increasing the carbon chain attached to thiol moiety at C-2 of imidazolone scaffold elevated the cytotoxic activity. Hence, compounds 4e and 4f, containing S-butyl fragment, exhibited the most antiproliferative activity against the tested cells where 4f showed extremely potent selectivity toward them. As well, compound 6a, containing imidazothienopyrimidine core, exerted significant cytotoxic activity and selectivity toward the examined cells. The mechanistic investigation of the most active cytotoxic analogs was achieved through the evaluation of their inhibitory activity against Chk1 and Chk2. Results revealed that 4f displayed potent dual inhibition of both Chk1 and Chk2 with IC50 equal 0.137 and 0.25 μM, respectively. It also promoted its antiproliferative and Chk suppression activity via EKVX cell cycle arrest at S phase through stimulating the apoptotic approach. The apoptosis induction was also emphasized by elevating the expression of Caspase-3 and Bax, that are accompanied by Bcl-2 diminution. The in silico molecular docking and ADMET profiles of the most active analogs have been carried out to evaluate their potential as significant anticancer drug candidates.

Recent advances and future directions on small molecule VEGFR inhibitors in oncological conditions

"A journey of mixed emotions" is a quote that best describes the progress chart of vascular endothelial growth factor receptor (VEGFR) inhibitors as cancer therapeutics in the last decade. Exhilarated with the Food and Drug Administration (FDA) approvals of numerous VEGFR inhibitors coupled with the annoyance of encountering the complications associated with their use, drug discovery enthusiasts are on their toes with an unswerving determination to enhance the rate of translation of VEGFR inhibitors from preclinical to clinical stage. The recently crafted armory of VEGFR inhibitors is a testament to their growing dominance over other antiangiogenic therapies for cancer treatment. This review perspicuously underscores the earnest attempts of the researchers to extract the antiproliferative potential of VEGFR inhibitors through the design of mechanistically diverse structural assemblages. Moreover, this review encompasses sections on structural/molecular properties and physiological functions of VEGFR, FDA-approved VEGFR inhibitors, and hurdles restricting the activity range/clinical applicability of VEGFR targeting antitumor agents. In addition, tactics to overcome the limitations of VEGFR inhibitors are discussed. A clear-cut viewpoint transmitted through this compilation can provide practical directions to push the cart of VEGFR inhibitors to advanced-stage clinical investigations in diverse malignancies.

Design, synthesis, and mechanistic insight of novel imidazolones as potential EGFR inhibitors and apoptosis inducers

As regards to the structural analysis and optimization of diverse potential EGFR inhibitors, two series of imidazolyl-2-cyanoprop-2-enimidothioates and ethyl imidazolylthiomethylacrylates were designed and constructed as potential EGFR suppressors. The cytotoxic effect of the prepared derivatives was assessed toward hepatic, breast, and prostate cancerous cells (Hep-G2, MCF-7, and PC-3). Three derivatives 3d, 3e, and 3f presented potent antiproliferative activity and selectivity against the examined tumor cells showing IC50 values at low micromolar levels. Hence, successive biological assays were applied to determine the probable mechanism of action of the new compounds. They exhibited significant EGFR suppression with an IC50 range of 0.137-0.507 µM. The most effective EGFR inhibitor 3f arrested the MCF-7 cell cycle at the S phase by inducing the apoptotic pathway that was confirmed via increasing the expression of Caspases 8, 9, and Bax, which are associated with Bcl-2 decline. Additionally, molecular docking displayed a distinctive interaction between 3f and EGFR binding pocket. Overall, this work introduces some novel imidazolyl-2-cyanoprop-2-enimidothioates and ethyl imidazolylthiomethylacrylates as potential cytotoxic and EGFR inhibitors that deserve further research in tumor therapy.

Structure-based development of 3,5-dihydroxybenzoyl-hydrazineylidene as tyrosinase inhibitor; in vitro and in silico study

A series of new analogs of 3,5-dihydroxybenzoyl-hydrazineylidene conjugated to different methoxyphenyl triazole (11a-n) synthesized using click reaction. The structures of all synthesized compounds were characterized by FTIR, 1H, 13C-NMR spectroscopy, and CHO analysis. The tyrosinase inhibitory potential of the synthesized compounds was studied. The newly synthesized scaffolds were found to illustrate the variable degree of the inhibitory profile, and the most potent analog of this series was that one bearing 4-methoxyphenyl moiety, and exhibited an IC50 value of 55.39 ± 4.93 µM. The kinetic study of the most potent derivative reveals a competitive mode of inhibition. Next, molecular docking studies were performed to understand the potent inhibitor's binding mode within the enzyme's binding site. Molecular dynamics simulations were accomplished to further investigate the orientation and binding interaction over time and the stability of the 11m-tyrosinase complex.

Novel benzochromenes: design, synthesis, cytotoxicity, molecular docking and mechanistic investigations

Aim: A novel series of fused benzochromenes with expected cytotoxicity and HIF-1α inhibition was identified. Materials & methods: A bioisosterism-aided approach was applied to design new benzochromenes and assess their cytotoxicity against three cancer cell lines. The probable mechanistic effect and the in silico docking and pharmacokinetic profiles of the most effective derivatives were evaluated. Results: Compounds 3, 4, 5, 8 and 11 showed potent antiproliferative activity and excellent selectivity. Compound 8 showed significant HIF-1α inhibition with an IC50 value of 3.372 μM. It also enhanced apoptosis and arrested the HepG2 cell cycle at both the G0/G1 and S stages. Conclusion: Compound 8 was identified as a new potential anticancer candidate.

Thiosemicarbazone-benzenesulfonamide Derivatives as Human Carbonic Anhydrases Inhibitors: Synthesis, Characterization, and In silico Studies

INTRODUCTION

Carbonic anhydrases (CAs) are widespread metalloenzymes with the core function of catalyzing the interconversion of CO2 and HCO3 -. Targeting these enzymes using selective inhibitors has emerged as a promising approach for the development of novel therapeutic agents against multiple diseases.

METHODS

A series of novel thiosemicarbazone-containing derivatives were synthesized, characterized, and tested for their inhibitory activity against pharmaceutically important human CA I (hCA I), II (hCA II), IX (hCA IX), and XII (hCA XII) using the single tail approach.

RESULTS

The compounds generally inhibited the isoenzymes at low nanomolar concentrations, with compound 6b having Ki values of 7.16, 0.31, 92.5, and 375 nM against hCA I, II, IX and XII, respectively. Compound 6e exhibited Ki values of 27.6, 0.34, 872, and 94.5 nM against hCA I, II, IX and XII, respectively.

CONCLUSION

To rationalize the inhibition data, molecular docking studies were conducted, providing insight into the binding mechanisms, molecular interactions, and selectivity of the compounds towards the isoenzymes.

Synthesis, Cytotoxic, and Computational Screening of Some Novel Indole-1,2,4-Triazole-Based S-Alkylated N-Aryl Acetamides

Molecular hybridization has emerged as the prime and most significant approach for the development of novel anticancer chemotherapeutic agents for combating cancer. In this pursuit, a novel series of indole-1,2,4-triazol-based N-phenyl acetamide structural motifs 8a-f were synthesized and screened against the in vitro hepatocellular cancer Hep-G2 cell line. The MTT assay was applied to determine the anti-proliferative potential of novel indole-triazole compounds 8a-f, which displayed cytotoxicity potential as cell viabilities at 100 µg/mL concentration, by using ellipticine and doxorubicin as standard reference drugs. The remarkable prominent bioactive structural hybrids 8a, 8c, and 8f demonstrated good-to-excellent anti-Hep-G2 cancer chemotherapeutic potential, with a cell viability of (11.72 ± 0.53), (18.92 ± 1.48), and (12.93 ± 0.55), respectively. The excellent cytotoxicity efficacy against the liver cancer cell line Hep-G2 was displayed by the 3,4-dichloro moiety containing indole-triazole scaffold 8b, which had the lowest cell viability (10.99 ± 0.59) compared with the standard drug ellipticine (cell viability = 11.5 ± 0.55) but displayed comparable potency in comparison with the standard drug doxorubicin (cell viability = 10.8 ± 0.41). The structure-activity relationship (SAR) of indole-triazoles 8a-f revealed that the 3,4-dichlorophenyl-based indole-triazole structural hybrid 8b displayed excellent anti-Hep-G2 cancer chemotherapeutic efficacy. The in silico approaches such as molecular docking scores, molecular dynamic simulation stability data, DFT, ADMET studies, and in vitro pharmacological profile clearly indicated that indole-triazole scaffold 8b could be the lead anti-Hep-G2 liver cancer therapeutic agent and a promising anti-Hep-G2 drug candidate for further clinical evaluations.

Quinazoline-based VEGFR-2 inhibitors as potential anti-angiogenic agents: A contemporary perspective of SAR and molecular docking studies

Angiogenesis, the formation of new blood vessels from the existing vasculature, is pivotal in the migration, growth, and differentiation of endothelial cells in normal physiological conditions. In various types of tumour microenvironments, dysregulated angiogenesis plays a crucial role in supplying oxygen and nutrients to cancerous cells, leading to tumour size growth. VEGFR-2 tyrosine kinase has been extensively studied as a critical regulator of angiogenesis; thus, inhibition of VEGFR-2 has been widely used for cancer treatments in recent years. Quinazoline nucleus is a privileged and versatile scaffold with a broad range of pharmacological activity, especially in the field of tyrosine kinase inhibitors with more than twenty small molecule inhibitors approved by the US Food and Drug Administration in the last two decades. As of now, the U.S. FDA has approved eleven small chemical inhibitors of VEGFR-2 for various types of malignancies, with a prime example being vandetanib, a quinazoline derivative, which is a multi targeted kinase inhibitor used for the treatment of late-stage medullary thyroid cancer. Despite of prosperous discovery and development of VEGFR-2 down regulator drugs, there still exists limitations in clinical efficacy, adverse effects, a high rate of clinical discontinuation and drug resistance. Therefore, there is an urgent need for the design and synthesis of more selective and effective inhibitors to tackle these challenges. Through the gathering of this review, we have strived to broaden the extent of our view over the entire scope of quinazoline-based VEGFR-2 inhibitors. Herein, we give an overview of the importance and advancement status of reported structures, highlighting the SAR, biological evaluations and their binding modes.

Molecular overlay-guided design of new CDK2 inhibitor thiazepinopurines: Synthesis, anticancer, and mechanistic investigations

Adopting the molecular overlay approach, three novel sets of thiazepinopurines with expected cytotoxicity and CDK2 inhibition potential were designed and synthesized. This was accomplished through the heteroannelation of purines, for the first time, with thiazepine. The obtained thiazepinopurines derivatives were assessed for their cytotoxicity toward tumor cells of three different types, HepG2, MCF-7, and PC-3 as well as one normal cell (WI38). Among the studied compounds, 3b and 3c exhibited significant antiproliferative activity against tumor cells presenting IC50 range of 5.52-17.09 µM in comparison with Roscovitine (9.32-13.82 µM). Additionally, both compounds displayed superior selectivity indices (SI = 3.00-7.15) toward tested cancer cells. The 4-chlorophenyl analog 3b has shown the best selectivity index, and hence it has been subjected to additional investigations to determine its proper mechanistic effect. Accordingly, the CDK2 inhibition potential, apoptosis induction, and cell cycle analysis of MCF-7 were evaluated. Results revealed that this analog displayed a potent CDK2 inhibition potential with an IC50 value of 0.219 µM. Findings also showed that 3b was thought to arrest MCF-7 cell cycle at S phase together with apoptosis induction by the increased expression of Bax, Caspase-8, and -9 markers with a concomitant decrease in Bcl-2 expression. Besides, the probable interaction of 3b with CDK2 binding pocket was investigated by molecular docking.

Novel 1,2,4-triazoles derived from Ibuprofen: synthesis and in vitro evaluation of their mPGES-1 inhibitory and antiproliferative activity

Some novel triazole-bearing ketone and oxime derivatives were synthesized from Ibuprofen. In vitro cytotoxic activities of all synthesized molecules against five cancer lines (human breast cancer MCF-7, human lung cancer A549, human prostate cancer PC-3, human cervix cancer HeLa, and human chronic myelogenous leukemia K562 cell lines) were evaluated by MTT assay. In addition, mouse embryonic fibroblast cells (NIH/3T3) were also evaluated to determine the selectivity. Compounds 18, 36, and 45 were found to be the most cytotoxic, and their IC50 values were in the range of 17.46-68.76 µM, against the tested cancer cells. According to the results, compounds 7 and 13 demonstrated good anti-inflammatory activity against the microsomal enzyme prostaglandin E2 synthase-1 (mPGES-1) enzyme at IC50 values of 13.6 and 4.95 µM. The low cytotoxicity and non-mutagenity of these compounds were found interesting. Also, these compounds significantly prevented tube formation in angiogenesis studies. In conclusion, the anti-inflammatory and angiogenesis inhibitory activities of these compounds without toxicity suggested that they may be promising agents in anti-inflammatory treatment and they may be supportive agents for the cancer treatment.

Aminopyridone-linked benzimidazoles: a fragment-based drug design for the development of CDK9 inhibitors

Aim: A fragment-based design and synthesis of three novel series of aminopyridone-linked benzimidazoles as potential anticancer candidates with significant CDK9 inhibition was implemented. Materials & methods: All synthesized compounds were submitted to National Cancer Institute, 60 cell lines and seven-dose cytotoxicity toward three cancer cells. Results: Compounds 2, 4a, 4c, 4d, 6a and 8a exhibited significant cytotoxicity and selectivity with IC50 range of 7.61-57.75 μM. Regarding the mechanism either in vitro or in silico, 4a, 6a and 8a displayed potent CDK9 inhibition with IC50 value of 0.424-8.461 μM. Compound 6a arrested the cell cycle at S phase and induced apoptosis in MCF-7 cells. Conclusion: Compound 6a is a promising CDK9 inhibitor that warrants additional research for cancer treatment.

Design and synthesis of novel uracil-linked Schiff bases as dual histone deacetylase type II/topoisomerase type I inhibitors with apoptotic potential

Aim: The previously reported dual histone deacetylase type II (HDAC II) / topoisomerase type I (Topo I) inhibitors suffer pharmacokinetic limitations because of their huge molecular weights. Materials & methods: We report the design and synthesis of a smarter novel set of uracil-linked Schiff bases (19-30) as dual HDAC II/Topo I inhibitors keeping the essential pharmacophoric features. Cytotoxicity of all compounds was assessed against three cancer cell lines. Studies of their effects on the apoptotic BAX and antiapoptotic BCL2 genes, molecular docking studies, and absorption, distribution, metabolism and excretion studies were conducted. Results: Compounds 22, 25 and 30 exhibited significant activities. The bromophenyl derivative 22 displayed the best selectivity index, with IC50 values against HDAC II and Topo I of 1.12 and 13.44 μM, respectively. Conclusion: Compound 22 could be considered a lead HDAC II/Topo I inhibitor.

Thiocarbohydrazone and Chalcone-Derived 3,4-Dihydropyrimidinethione as Lipid Peroxidation and Soybean Lipoxygenase Inhibitors

The potential of the 4,6-diphenyl-3,4-dihydropyrimidine-2(1H)-thione (abbreviated as KKII5) and (E)-N'-benzylidenehydrazinecarbothiohydrazide (abbreviated as DKI5) compounds as possible drug leads is investigated. KKII5 and DKI5 are synthesized in high yield of up to 97%. Their structure, binding in the active site of the LOX-1 enzyme, and their toxicity are studied via joint experimental and computational methodologies. Specifically, the structure assignment and conformational analysis were achieved by applying homonuclear and heteronuclear 2D nuclear magnetic resonance (NMR) spectroscopy (2D-COSY, 2D-NOESY, 2D-HSQC, and 2D-HMBC) and density functional theory (DFT). The obtained DFT lowest energy conformers were in agreement with the NOE correlations observed in the 2D-NOESY spectra. Additionally, docking and molecular dynamics simulations were performed to discover their ability to bind and remain stabile in the active site of the LOX-1 enzyme. These in silico experiments and DFT calculations indicated favorable binding for the enzyme under study. The strongest binding energy, -9.60 kcal/mol, was observed for dihydropyrimidinethione KKII5 in the active site of LOX-1. ADMET calculations showed that the two molecules lack major toxicities and could serve as possible drug leads. The redox potential of the active center of LOX-1 with the binding molecules was calculated via DFT methodology. The results showed a significantly smaller energy attachment of 2.8 eV with KKII5 binding in comparison to DKI5. Thus, KKII5 enhanced the ability of the active center to receive electrons compared to DKI5. This is related to the stronger binding interaction of KKII5 relative to that of DK15 to LOX-1. The two very potent LOX-1 inhibitors exerted IC₅₀ 19 μΜ (KKII5) and 22.5 μΜ (DKI5). Furthermore, they both strongly inhibit lipid peroxidation, namely, 98% for KKII5 and 94% for DKI5.

Exploring the cytotoxic effect and CDK-9 inhibition potential of novel sulfaguanidine-based azopyrazolidine-3,5-diones and 3,5-diaminoazopyrazoles

Regarding the structural analysis of variable effective CDK-9 suppressors, we record the design and synthesis of two new sets of sulfaguanidine-based azopyrazolidine-3,5-diones and 3,5-diaminoazopyrazoles with expected anticancer and CDK-9 inhibiting activity. In the designed molecules, the pyrazole ring and sulphaguanidine fragment were linked together for the first time through diazo linkers as they are expected to enhance the anticancer activity and CDK degrading interaction. All derivatives have been estimated regarding their cytotoxic activity toward three tumor cells where CDK overexpression has been reported (HePG2, HCT-116, and MCF-7). Among these, four derivatives VII, VIII, X, and XIII exerted potent cytotoxicity against the chosen tumor cells presenting IC₅₀ range equal to 2.86-25.89 µM. As well cytotoxicity on non-cancer cells and CDK-9 inhibition assay have been also assessed for these candidates to evaluate their selectivity indices and enzyme inhibition. The 3,5-diaminopyrazole-1-carboxamide derivative XIII showed a superior combined profile as cytotoxic with high selectivity toward cancer cells (HePG2: IC₅₀ = 6.57 µM, SI = 13.31; HCT-116: IC₅₀ = 9.54 µM, SI = 9.16; MCF-7: IC₅₀ = 7.97 µM, SI = 10.97). Accordingly, it has been chosen to evaluate its probable mechanistic effect both in vitro (via enzyme assay, apoptosis induction, and cell cycle study) as well as in silico (through molecular docking). Overall, this work introduces the 3,5-diaminopyrazole-1-carboxamide derivative XIII as a potent CDK-9 inhibitor candidate (IC₅₀ = 0.16 µM) that merits further investigations for the management of breast, colorectal, and hepatic malignancies.

Phenylpyrazolone-1,2,3-triazole Hybrids as Potent Antiviral Agents with Promising SARS-CoV-2 Main Protease Inhibition Potential

COVID-19 infection is now considered one of the leading causes of human death. As an attempt towards the discovery of novel medications for the COVID-19 pandemic, nineteen novel compounds containing 1,2,3-triazole side chains linked to phenylpyrazolone scaffold and terminal lipophilic aryl parts with prominent substituent functionalities were designed and synthesized via a click reaction based on our previous work. The novel compounds were assessed using an in vitro effect on the growth of SARS-CoV-2 virus-infested Vero cells with different compound concentrations: 1 and 10 μM. The data revealed that most of these derivatives showed potent cellular anti-COVID-19 activity and inhibited viral replication by more than 50% with no or weak cytotoxic effect on harboring cells. In addition, in vitro assay employing the SARS-CoV-2-Main protease inhibition assay was done to test the inhibitors' ability to block the common primary protease of the SARS-CoV-2 virus as a mode of action. The obtained results show that the one non-linker analog 6h and two amide-based linkers 6i and 6q were the most active compounds with IC₅₀ values of 5.08, 3.16, and 7.55 μM, respectively, against the viral protease in comparison to data of the selective antiviral agent GC-376. Molecular modeling studies were done for compound placement within the binding pocket of protease which reveal conserved residues hydrogen bonding and non-hydrogen interactions of 6i analog fragments: triazole scaffold, aryl part, and linker. Moreover, the stability of compounds and their interactions with the target pocket were also studied and analyzed by molecular dynamic simulations. The physicochemical and toxicity profiles were predicted, and the results show that compounds behave as an antiviral activity with low or no cellular or organ toxicity. All research results point to the potential usage of new chemotype potent derivatives as promising leads to be explored in vivo that might open the door to rational drug development of SARS-CoV-2 Main protease potent medicines.

A novel class of phenylpyrazolone-sulphonamides rigid synthetic anticancer molecules selectively inhibit the isoform IX of carbonic anhydrases guided by molecular docking and orbital analyses

All the previously reported phenylpyrazoles as carbonic anhydrase inhibitors (CAIs) were found to have small sizes and high levels of flexibility, and hence showed low selectivity profiles toward a particular isoform of CA. Herein, we report the development of a more rigid ring system bearing a sulfonamide hydrophilic head and a lipophilic tail to develop novel molecules that are suggested to have a better selectivity toward a special CA isoform. Accordingly, three novel sets of pyrano[2,3-c]pyrazoles attached with sulfonamide head and aryl hydrophobic tail were synthesized to enhance the selectivity toward a specific isoform of human carbonic anhydrases (hCAs). The impact of both attachments on the potency and selectivity has been extensively discussed in terms of in vitro cytotoxicity evaluation under hypoxic conditions, structure-activity relationship and carbonic anhydrase enzyme assay. All of the new candidates displayed good cytotoxic activities against breast and colorectal carcinomas. Results of the carbonic anhydrase enzyme assay demonstrated the preferential of compounds 22, 24 and 27 to inhibit the isoform IX of hCAs selectively. Wound-healing assay has also been performed and revealed the potential of 27 to decrease the wound closure percentage in MCF-7 cells. Molecular docking and molecular orbital analysis have finally been conducted. Results indicate the potential binding interactions of 24 and 27 with several crucial amino acids of the hCA IX.Communicated by Ramaswamy H. Sarma.

The anticancer and EGFR-TK/CDK-9 dual inhibitory potentials of new synthetic pyranopyrazole and pyrazolone derivatives: X-ray crystallography, in vitro, and in silico mechanistic investigations

Treatment options for the management of breast cancer are still inadequate. This inadequacy is attributed to the lack of effective targeted medications, often resulting in the recurrence of metastatic disorders. Cumulative evidence suggests that epidermal growth factor receptor (EGFR-TK) and cyclin-dependent kinases-9 (CDK-9) overexpression correlates with worse overall survival in breast cancer patients. Pyranopyrazole and pyrazolone are privileged options for the development of anticancer agents. Inspired by this proven scientific fact, we report here the synthesis of two new series of suggested anticancer molecules incorporating both heterocycles together with their characterization by IR, 1H NMR, 13C NMR, 13C NMR-DEPT, and X-ray diffraction methods. An attempt to get the pyranopyrazole-gold complexes was conducted but unexpectedly yielded benzylidene-2,4-dihydro-3H-pyrazol-3-one instead. This unexpected result was confirmed by X-ray crystallographic analysis. All newly synthesized compounds were assessed for their anti-proliferative activity against two different human breast cancer cells, and the obtained results were compared with the reference drug Staurosporine. The target compounds revealed variable cytotoxicity with IC50 at a low micromolar range with superior selectivity indices. Target enzyme EGFR-TK and CDK-9 assays showed that compounds 22 and 23 effectively inhibited both biological targets with IC50 values of 0.143 and 0.121 µM, respectively. Molecular docking experiments and molecular dynamics simulation were also conducted to further rationalize the in vitro obtained results.Communicated by Ramaswamy H. Sarma.

Exploring the dual effect of novel 1,4-diarylpyranopyrazoles as antiviral and anti-inflammatory for the management of SARS-CoV-2 and associated inflammatory symptoms

COVID-19 and associated substantial inflammations continue to threaten humankind triggering death worldwide. So, the development of new effective antiviral and anti-inflammatory medications is a major scientific goal. Pyranopyrazoles have occupied a crucial position in medicinal chemistry because of their biological importance. Here, we report the design and synthesis of a series of sixteen pyranopyrazole derivatives substituted with two aryl groups at N-1 and C-4. The designed compounds are suggested to show dual activity to combat the emerging Coronaviruses and associated substantial inflammations. All compounds were evaluated for their in vitro antiviral activity and cytotoxicity against SARS-CoV infected Vero cells. As well, the in vitro assay of all derivatives against the SARS-CoV M^pro target was performed. Results revealed the potential of three pyranopyrazoles (22, 27, and 31) to potently inhibit the viral main protease with IC₅₀ values of 2.01, 1.83, and 4.60 μM respectively compared with 12.85 and 82.17 μM for GC-376 and lopinavir. Additionally, in vivo anti-inflammatory testing for the most active compound 27 proved its ability to reduce levels of two cytokines (TNF-α and IL-6). Molecular docking and dynamics simulation revealed consistent results with the in vitro enzymatic assay and indicated the stability of the putative complex of 27 with SARS-CoV-2 M^pro. The assessment of metabolic stability and physicochemical properties of 27 have also been conducted. This investigation identified a set of metabolically stable pyranopyrazoles as effective anti-SARS-CoV-2 M^pro and suppressors of host cell cytokine release. We believe that the new compounds deserve further chemical optimization and evaluation for COVID-19 treatment.

In vitro and computational investigations of novel synthetic carboxamide-linked pyridopyrrolopyrimidines with potent activity as SARS-CoV-2-MPro inhibitors

An essential target for COVID-19 is the main protease of SARS-CoV-2 (M^pro). With the objective of targeting this receptor, a novel set of pyrido[1,2-a]pyrrolo[2,3-d]pyrimidines with terminal carboxamide fragments was designed, synthesized, and considered as an initial motif for the creation of effective pan-coronavirus inhibitors. Accordingly, nine derivatives (21–29) have been introduced for in vitro assay to evaluate their antiviral activity and cytotoxicity effect against COVID-19 virus using Vero cells. The obtained data revealed that the majority of these derivatives showed potent cellular anti-COVID-19 activity and prevent viral growth by more than 90% at two different concentrations with weak or even no detectable cytotoxic effect on Vero cells. Extensive molecular docking simulations highlighted proper non-covalent interaction of new compounds within the binding pocket of M^pro as a potential target for their antiviral activity. In vitro assay for all the synthesized derivatives against the viral M^pro target indicated that compounds 25 and 29 have promising inhibitory activity with IC₅₀ values at low micromolar concentrations. The molecular dynamic simulation results predicted the stability of compound 29 in the binding cavity of SARS-CoV-2 M^pro and hence supported the high inhibitory activity shown by the In vitro assay. These results suggested that compounds 25 and 29 merit further investigations as promising drug candidates for the management of SARS-CoV-2.

An essential target for COVID-19 is the main protease of SARS-CoV-2 (M^pro).