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

Development of indole hybrids for potential lung cancer treatment - part II

Lung cancer has become the most prevalent cancer for the past three decades, and the 5-years survival rate of lung cancer is only ~20% nowadays. Chemotherapy is the mainstay of lung cancer therapy, especially for non-small cell lung cancer. However, drug resistance represents a principal cause of therapeutic failure in non-small cell lung cancer leading to therapeutic insensitivity, tumor recurrence, and disease progression. Indole hybrids have the potential to conquer drug resistance, enhance efficacy, reduce adverse events, and improve pharmacokinetic properties due to their capacity to inhibit multiple targets simultaneously. Moreover, indole hybrids osimertinib, mobocertinib, cediranib, and vizimpro are currently applied in clinics for lung cancer therapy, demonstrating that indole hybrids are valuable scaffolds in the treatment and eradication of lung cancer. This review provides a comprehensive overview of the evolving landscape of indole hybrids with the in vitro and in vivo efficacy against lung cancer, and the structure-activity relationships as well as mechanisms of action are also discussed, covering articles published from 2021 onward.

Indole-Boron-Difluoride Complexes with Anticancer and Fluorescence Properties

Eight indole-boron-difluoride complexes were synthesized from 2,3-arylpyridylindole derivatives via Sonogashira coupling and Larock heteroannulation. These complexes exhibited distinct photophysical properties. Solvent polarity influenced their spectral behavior showing hypsochromic absorption, bathochromic emission shifts, and aggregation-induced emission (AIE) in mixed solvents. The ¹⁹F NMR shifts and photophysical properties, including excitation, emission maxima, and Stokes shift, correlated with Hammett substituent constants highlighting electronic effects on molecular properties. The synthesized complexes exhibited a range of intramolecular charge transfer (ICT) behaviors, as evidenced by their Lippert-Mataga parameters. TD-DFT calculations aligned with experimental data, offering insight into spectroscopic behavior. Notably, the indole-boron-difluoride complex bearing a methyl ester group exhibited significant anticancer activity against HeLa cells and potential for fluorescence imaging, indicating its promise for biomedical applications in cell imaging and therapy.

Development of 1,2,3-triazole hybrids as multi-faced anticancer agents co-targeting EGFR/mTOR pathway and tubulin depolymerization

Novel 1,2,3-triazole hybrids bearing various substituents have been synthesized as potential anticancer agents. Ligand-based approach has been adopted to design these compounds relying on the hybridization of 1,2,3-triazole with α,β-unsaturated carbonyl, 5- and 6-membered heterocyclic scaffolds. All synthesized members were investigated for their cytotoxic potency against nine types comprising 60 panels of human cancerous cells by the US National Cancer Institute: Development Therapeutic Program (US_NCI_DTP). Among the tested members, 4b, 4e, and 4h showed prominent cytotoxic effects (> 80 % growth inhibition: GI) on a wide panel of tested cancer cell lines, mainly melanoma and colorectal cancer redeeming their selection for five dose testing. Presenting low nanomolar GI50 concentrations, two representative potent anticancer compounds 4b and 4e were subjected to cytotoxicity testing on colon normal cell (FHC) to investigate their safety window and they showed less toxicity to normal cells at the concentration required to produce anticancer effect. Furthermore, 4b and 4e were exposed to additional mechanistic studies in colorectal cancer cell HCT-116 suggesting multifaceted mechanisms of action. A study into the effects of cytotoxic chemicals 4b and 4e on cell cycle progression regulation showed triggered the arrest of cell cycles during the G1 and S phases. Moreover, 4b and 4e caused cell death mainly through apoptosis the thing that has been reinforced by the elevated Bax: Bcl2 ratio, as well as concentrations of caspases 3 and 9 within HCT-116. Further, both compounds showed prominent inhibition profiles against tubulin polymerization as well as EGFR catalytic activity reaching down to low-digit micromolar and sub-micromolar concentrations, respectively, as compared to positive reference controls. Compounds' impacts on gene expression of cancer-associated and EGFR-downstream signaling markers including TNFα, IL-6, and mTOR, were explored in HCT-116 highlighted significant downregulations versus the untreated cells. Docking studies demonstrated the specific fit of 4b and 4e into EGFR and the colchicine binding site of tubulin.

In Vitro Enzymatic and Computational Assessments of Pyrazole-Isatin and Pyrazole-Indole Conjugates as Anti-Diabetic, Anti-Arthritic, and Anti-Inflammatory Agents

Background/Objectives: Recently, the prevalence of diseases such as diabetes, arthritis, and inflammatory diseases, along with their complications, has become a significant health problem. This is in addition to the various biomedical applications of pyrazole, isatin, and indole derivatives. Accordingly, cooperation will continue between chemistry scientists, pharmaceutical scientists, and human doctors to produce hybrid compounds from pyrazole with isatin or indole possessing biological activities as anti-diabetic, anti-arthritic, and anti-inflammatory agents. Methods: The two series of pyrazole-isatin conjugates 12a-h and pyrazole-indole conjugates 14a-d were prepared from our previous works via the direct reaction of 5-amino-pyrazoles 10a-d with N-alkyl isatin 11a,b, and 1H-indole-3-carbaldehyde (13), respectively, using the previously reported procedure. The potential biological activities of 12a-h and 14a-d as anti-diabetic, anti-arthritic, and anti-inflammatory agents were assessed through estimated inhibition percentage (%) and the median inhibitory concentrations (IC50) using methods described in the literature. Further, the computational assessments of 12a-h and 14a-d such as toxic doses (the median lethal dose, LD50), toxicity classes, drug-likeness model scores (DLMS), molecular lipophilicity potential (MLP) maps, polar surface area (PSA) maps, and topological polar surface area (TPSA) values were predicted using available free websites. Results: The in vitro enzymatic assessment results showed that pyrazole-indole conjugate 14b possesses powerful activities against (i) α-amylase (% = 65.74 ± 0.23, IC50 = 4.21 ± 0.03 µg/mL) and α-glucosidase (% = 55.49 ± 0.23, IC50 = 2.76 ± 0.01 µg/mL); (ii) the protein denaturation enzyme (% = 49.30 ± 0.17) and against the proteinase enzyme (% = 46.55 ± 0.17) with an IC50 value of 6.77 ± 0.01 µg/mL; (iii) the COX-1, COX-2, and 5-LOX enzymes with an IC50 of 5.44 ± 0.03, 5.37 ± 0.04, and 7.52 ± 0.04, respectively, which is almost close to the IC50 of the indomethacin and zileuton drugs. Also, the computational assessment results showed (i) the conjugate 14b possesses lipophilic surface properties thus can cross cell membranes, and is effective for treatment; (ii) all the conjugates possess a TPSA value of more than 140 Å2 thus possess good intestinal absorption. Conclusions: The two series of pyrazole-isatin conjugates 12a-h and pyrazole-indole conjugates 14a-d were synthesized from our previous works. The results of these in vitro enzymatic and computational assessments concluded that the pyrazole-indole conjugate 14b possesses powerful activities against various studied enzymes and possesses good computational results. In the future, our research team will present in vitro, in vivo biological, and computational assessments to hopefully obtain effectual agents such as anti-diabetic, anti-arthritic, and anti-inflammatory.

Bioactive Fused Pyrazoles Inspired by the Adaptability of 5-Aminopyrazole Derivatives: Recent Review

Heterocyclic compounds, especially those containing the pyrazole moiety, are highly significant in organic chemistry and possess remarkable and diverse biological properties. The 5-aminopyrazole derivatives are key starting materials for the synthesis of numerous bioactive compounds such as pyrazolopyridine, pyrazolopyrimidine, pyrazoloquinazoline, and pyrazolotriazine derivatives. Many compounds inspired by the 5-aminopyrazole derivatives possess a wide spectrum of biological activities and medicinal applications such as antioxidants, anticancer agents, enzyme inhibitors, antimicrobials, and anti-tuberculosis activities. This review summarizes the recently reported synthesis methods and biological activities of fused pyrazole and pyrazole-based derivatives based on 5-aminopyrazole compounds within the last 5 years (2020 to present). One of the important goals of this review is to illustrate future strategies for the design, development, and utilization of pyrazole products as potent drugs.

Acetic Acid-Driven One-Pot Synthesis of 4,7-dihydro-[1,2,3]thiadiazolo[5,4-b]pyridine-6-carboxamides and Pharmacological Evaluations

A diverse set of 4,7-dihydro-[1,2,3]thiadiazolo[5,4-b]pyridine-6-carboxamides 4(a-o) was synthesized via a one-pot reaction of 5-amino-[1,2,3]thiadiazole, various aromatic aldehydes, and different acetoacetanilides, using glacial acetic acid. The resulting compounds were obtained in moderate to good yields. All the newly synthesized compounds were evaluated for their antimicrobial activity. Among them, compound 4 e demonstrated superior efficacy against the Salinivibrio proteolyticus strain of Gram-negative bacteria compared to ciprofloxacin. Compound 4 d exhibited the highest potency against the fungal strain Candida albicans, surpassing amphotericin B. The physicochemical characteristics of 4 d and 4 e were assessed. According to docking analysis, DHTDAPy 4 e shows a higher binding affinity of -7.2 kcal/mol in the binding cavity of the receptor. These findings illustrate the safety, tolerability, and potency of the newly synthesized DHTDAPy compounds against fungal and bacterial infections.

Design, synthesis, and in silico studies of new quinazolinones tagged thiophene, thienopyrimidine, and thienopyridine scaffolds as antiproliferative agents with potential p38α MAPK kinase inhibitory effects

The current work focuses on the creation of novel derivatives of the quinazolinone ring system, with various substituted thiophene, thienopyrimidine, and thienopyridine scaffolds 3a,b-11. Employing the standard MTT assay, every target compound's in vitro antiproliferative efficacy was evaluated in comparison with doxorubicin against both normal WI-38 cells and various cancer cell lines. Derivatives 6, 8a, and 8b demonstrated the most potent activity, alongside their safety profiles against WI-38. The in vitro enzyme assay showed that the new analogues had a better ability to inhibit p38α MAPK kinase than SB 202190 (IC50s = 0.18 ± 0.02, 0.23 ± 0.05, 0.31 ± 0.04, and 0.27 ± 0.06 μM, respectively). Additionally, apoptosis tests conducted on MCF-7 cells revealed that 6, 8a, and 8b significantly increased the levels of Bax (by approximately 7.31, 13.8, and 8.86 fold) and caspase 3 (by approximately 3.55, 4.22, and 3.87 fold), respectively, in comparison to the untreated cells. They decreased the amount of Bcl-2 by ∼1.99, 3.69, and 2.66 fold, respectively. The most powerful counterpart, 8a, underwent additional investigation of the cell cycle and apoptosis. It caused necrotic and apoptotic effects in the late stages and stopped the MCF-7 cell cycle at the G2/M phase. Based on the molecular docking study, candidates 6, 8a, and 8b all fit well within p38α MAPK kinase, with energy scores of -10.88, -11.28, and -10.96 kcal mol-1, respectively. Based on the in silico computer examination of physico-chemical and ADMET properties, the latter analogues seem to be promising candidates for further development and optimization in research.

In vivo evaluation of novel synthetic pyrazolones as CDK9 inhibitors with enhanced pharmacokinetic properties

Aim: The structural optimization of our recently reported CDK9 inhibitor to furnish novel aminopyrazolones and methylpyrazolones with improved pharmacokinetics.Materials & methods: The synthesis of the targeted compounds was accomplished via conventional, grinding and microwave-assisted processes. The cytotoxicity of them was assayed against three carcinomas.Results: Analogs 2, 4 and 6 showed significant cytotoxicity and selectivity toward all tested cells. They also displayed potent CDK9 inhibition. Compound 6 arrested MCF-7 cycle at G2/M phase by stimulating the apoptotic pathway. The in vivo biodistribution of radiolabeled compound 6 displayed a potent targeting capability of 131I in solid tumors.Conclusion: Entity 6 is a potent CDK9 inhibitor where 131I-compound 6 can be used as a significant radiopharmaceutical imaging tool for tumors.

Recent highlights in the synthesis and biological significance of pyrazole derivatives

Aza-heterocyclic scaffolds are privileged cores in the composition of their potential therapeutic profiles and versatile synthetic intermediates. Pyrazole is one of the frequently studied compounds of "azole" family and consists of nitrogen in a 1,2 linking sequence. These motifs possess a wide-spectrum of applications in the field of pharmaceuticals, agrochemicals, polymer chemistry, cosmetics, food industries and more. In addition, functionalized pyrazole derivatives are frequently used as ligands in coordination chemistry and metal-catalysed reactions. As exemplified by numerous recent reports, pyrazoles are highly promising pharmacophores with excellent therapeutic applications. Owing to their aromaticity, the ring structures have many reactive positions, where electrophilic, nucleophilic, alkylation and oxidative reactions might occur. The structural adroitness and diversity of pyrazole cores further emanated numerous fused bicyclic skeletons with various biological applications. In this review, we highlight the recent synthetic methods developed for the preparation of functionalized pyrazole derivatives (From 2017 to present). In addition, we have also covered the notable biological activities (anti-cancer, anti-inflammatory, anti-bacterial and anti-viral) of this ubiquitous core. Herein, we emphasised the synthesis of pyrazoles from variety of precursors such as, alkynes, α,β-unsaturated carbonyl compounds, diazo reagents, nitrile imines, diazonium salts, 1,3-dicarbonyl compounds and etc. Moreover, the recent synthetic methodologies focusing on the preparation of pyrazolines and pyrazolones and variously fused-pyrazoles are also included. Authors expect this review could significantly help the researchers in finding elegant novel tools to synthesize pyrazole skeletons and expand their biological evaluation.

Design, synthesis, and biological investigations of new pyrazole derivatives as VEGFR2/CDK-2 inhibitors targeting liver cancer

New Series of N-Manniche bases 3,4 (a-c) and 5,6 (a-b) were synthesized through the reaction of benzaldehyde and amine with 3-methyl-4-(aryldiazenyl)-1H-pyrazol-5-ol derivatives 2(a-c), they were fully characterized by FT-IR, (1H, 13C) NMR data in addition to their mass spectra. The Structural Activity Relationship of the target compounds were examined for their cytotoxicity. Some newly synthesized compounds showed promising antiproliferation properties when tested against HepG2 cancer cells. Compounds 4a, 5a, and 6b showed potent cytotoxicity against HepG2 with IC50 values of 4.4, 3.46 and 2.52 µM compared to Sorafenib (IC50 = 2.051 µM) and Roscovitine (IC50 = 4.18 µM). Furthermore, they were safe against the THLE2 cells with higher IC50 values. Compound 6b exhibited promising dual VEGFR2/CDK-2 inhibition activities; it had an IC50 value of 0.2 μM with VEGFR2 inhibition of 93.2%, and it had an IC50 value of 0.458 μM with CDK-2 inhibition of 88.7%. In comparison to the untreated control group (0.95%), compounds 5a (38.32%) and 6b (42.9%) considerably increased the cell population in total apoptosis. In addition, compounds 5a and 6b arrested the cell population at G0-G1 and S phases, respectively. Molecular docking experiments confirmed the virtual binding mechanism of the most active drugs, which were found to have good binding affinities with both receptor active sites.

Novel quinazolin-4-one based derivatives bearing 1,2,3-triazole and glycoside moieties as potential cytotoxic agents through dual EGFR and VEGFR-2 inhibitory activity

The toxicity that was caused by the developed medications for anticancer treatment is, unfortunately, an earnest problem stemming from the various involved targets, and accordingly, intense research for overcoming such a phenomenon remains indispensable. In the current inquiry, an innovative category of substituted quinazoline-based glycosides incorporating a core of 1,2,3-triazole and attached to distinct acetylated likewise deprotected sugar segments are created and produced synthetically. The resulted 1,2,3-triazolyl-glycosides products were investigated for their ability to cause cytotoxicity to several human cancer cell lines. The quinazoline based glycosyl-1,2,3-triazoles 10-13 with free hydroxy sugar moiety revealed excellent potency against (IC50 range = 5.70-8.10 µM, IC50 Doxorubicin = 5.6 ± 0.30 µM, IC50 Erlotinib = 4.3 ± 0.1 µM). against MCF-7 cancer cell line. In addition, the derived glycosides incorporating quinazolinone and triazole core 6-13 with acetylated and deprotected sugar parts showed excellent and superior potency against HCT-116 (IC50 range = 2.90-6.40 µM). The potent products were revealed as safe cytotoxic agents as indicated by their studied safety profiles. Additional research of promising candidates inhibitory analysis performed against EGFR and VEGFR-2. The hydroxylated glycosides incorporating triazole and quinazoline system 11 and 13 with N-methyl substitution of quinazolinone, gave excellent potency against EGFR (IC50 = 0.35 ± 0.11 and 0.31 ± 0.06 µM, correspondingly) since glycoside 13 revealed comparable IC50 (3.20 ± 0.15 µM) to sorafenib against VEGFR-2. For more understanding of its action mode, it was analyzed how the 1,2,3-triazolyl glycoside 13 made an effect on the apoptosis induction and the arrest of the cell cycle. It was revealed that it had the ability to stop HCT-116 cells in their cell cycle's G1 stage. Moreover, the influence of quinazolinone-1,2,3-triazole-glycoside 13 upon p53, Bax, and Bcl-2 levels in HCT-116 units was also studied for future approaches toward its behavior. Additionally, the latter derivative may trigger apoptosis, as indicated by a significant increase in apoptotic cells. Furthermore, molecular docking was simulated to make an obvious validation and comprehension acquirement of the binding's characteristics also attractions among the most forceful compounds side by side with their aimed enzymes.

Current scenario of pyrazole hybrids with anti-breast cancer therapeutic applications

Breast cancer stands as the leading cause of cancer-related deaths among women globally, but current therapy is restricted to the serious adverse effects and multidrug resistance, necessitating the exploration of novel, safe, and efficient anti-breast cancer chemotherapeutic agents. Pyrazoles exhibit excellent potential for utilization as effective anti-breast cancer agents due to their ability to act on various biological targets. Particularly, pyrazole hybrids demonstrated the advantage of targeting multiple pathways, and some of them, which are exemplified by larotrectinib (pyrazolo[1,5-a]pyrimidine hybrid), can be applied for breast cancer therapy. Thus, pyrazole hybrids hold great promise as useful therapeutic interventions for breast cancer. The aim of this review is to summarize the current scenario of pyrazole hybrids with in vitro and/or in vivo anti-breast cancer potential, along with the modes of action and structure-activity relationships, covering articles published from 2020 to the present, to streamline the development of rational, effective and safe anti-breast cancer candidates.

New sulfonamide-based glycosides incorporated 1,2,3-triazole as cytotoxic agents through VEGFR-2 and carbonic anhydrase inhibitory activity

New sulfonamide-triazole-glycoside hybrids derivatives were designed, synthesised, and investigated for anticancer efficacy. The target glycosides' cytotoxic activity was studied with a panel of human cancer cell lines. Sulfonamide-based derivatives, 4, 7 and 9 exhibited promising activity against HepG-2 and MCF-7 (IC50 = 8.39-16.90 μM against HepG-2 and 19.57-21.15 μM against MCF-7) comparing with doxorubicin (IC50 = 13.76 ± 0.45, 17.44 ± 0.46 μM against HepG-2 and MCF-7, rescpectively). To detect the probable action mechanism, the inhibitory activity of these targets was studied against VEGFR-2, carbonic anhydrase isoforms hCA IX and hCA XII. Compoumds 7 and 9 gave favorable potency (IC50 = 1.33, 0.38 μM against VEGFR-2, 66, 40 nM against hCA IX and 7.6, 3.2 nM against hCA XII, respectively), comparing with sorafenib and SLC-0111 (IC50 = 0.43 μM, 53 and 4.8 nM, respectively). Moreover, the docking simulation was assessed to supply better rationalization and gain insight into the binding affinity between the promising derivatives and their targeted enzymes that was used for further modification in the anticancer field.

Design, synthesis, in silico and biological evaluation of new indole based oxadiazole derivatives targeting estrogen receptor alpha

A series of new indole-oxadiazole derivatives was designed and synthesized to develop potential anti-breast cancer agents. The compounds exhibited significant inhibitory activity with IC50 values ranging from 1.78 to 19.74 μM against ER-positive human breast cancer (BC) cell lines T-47D and MCF-7. Among them, compounds (5a, 5c, 5e-5h, 5j-5o) displayed superior activity against ER-α dominant (ratio of ER-α/ER-β is 9/1) T-47D cells compared to the standard drug bazedoxifene (IC50 = 12.78 ± 0.92 μM). Compounds 5c and 5o exhibited remarkable anti-proliferative activity with IC50 values of 3.24 ± 0.46 and 1.72 ± 1.67 μM against T-47D cells, respectively. Further, compound 5o manifested 1589-fold higher ER-α binding affinity (213.4 pM) relative to bazedoxifene (339.2 nM) in a competitive ER-α binding assay, while compound 5c showed a binding affinity of 446.6 nM. The Western blot analysis proved that both compounds influenced the ER-α protein's expression, impeding its subsequent transactivation and signalling pathway within T-47D cells. Additionally, a molecular docking study suggests that compounds 5c and 5o bind in such a fashion that induces conformational changes in the protein, culminating in their antagonistic effect. Also, pharmacokinetic profiles showed that all compounds have drug-like properties. Further, molecular dynamic (MD) simulations and density functional theory (DFT) analysis confirmed the stability, conformational behaviour, reactivity, and biological feasibility of compounds 5c and 5o. In conclusion, based on our findings, compounds 5c and 5o, which exhibit significant ER-α antagonistic activity, can act as potential lead compounds for developing anti-breast cancer agents.

Exploring the Potential Biological Activities of Pyrazole-Based Schiff Bases as Anti-Diabetic, Anti-Alzheimer's, Anti-Inflammatory, and Cytotoxic Agents: In Vitro Studies with Computational Predictions

In this innovative research, we aim to reveal pyrazole-based Schiff bases as new multi-target agents. In this context, we re-synthesized three sets of pyrazole-based Schiff bases, 5a-f, 6a-f, and 7a-f, to evaluate their biological applications. The data from in vitro biological assays (including antioxidant and scavenging activities, anti-diabetes, anti-Alzheimer's, and anti-inflammatory properties) of the pyrazole-based Schiff bases 5a-f, 6a-f, and 7a-f showed that the six pyrazole-based Schiff bases 5a, 5d, 5e, 5f, 7a, and 7f possess the highest biological properties among the compounds evaluated. The cytotoxicity against lung (A549) and colon (Caco-2) human cancer types, as well as normal lung (WI-38) cell lines, was evaluated. The data from the cytotoxicity investigation demonstrated that the three Schiff bases 5d, 5e, and 7a are active against lung (A549) cells, while the two Schiff bases 5e and 7a exhibited the highest cytotoxicity towards colon (Caco-2) cells. Additionally, the enzymatic activities against caspase-3 and Bcl-2 of the six pyrazole-based Schiff bases 5a, 5d, 5e, 5f, 7a, and 7f were evaluated. Furthermore, we assessed the in silico absorption, distribution, metabolism, and toxicity (ADMT) properties of the more potent pyrazole-based Schiff bases. After modifying the structures of the six pyrazole-based Schiff bases, we plan to further extend the studies in the future.

Microwave-induced one-pot synthesis of 3-imidazolyl indole clubbed 1,2,3-triazole hybrids as antiproliferative agents and density functional theory study

Herein, we outline a highly efficient PEG-4000-mediated one-pot three-component reaction for the synthesis of 3-imidazolyl indole clubbed 1,2,3-triazole derivatives (5a-r) at up to 96% yield as antiproliferative agents. This three-component protocol offers the advantages of an environmentally benign reaction, excellent yield, quick response time, and operational simplicity triggered by the copper catalyst under microwave irradiation. All the synthesized compounds were tested for antiproliferative activity against six human solid tumor cell lines, that is, A549 and SW1573 (nonsmall cell lung), HBL100 and T-47D (breast), HeLa (cervix), and WiDr (colon). Among them, six compounds, 5g-j, 5m, and 5p, demonstrated effective antiproliferative action with GI50 values under 10 μM. Furthermore, density functional theory (DFT) calculations were performed for all the synthesized molecules through geometry optimizations, frontier molecular orbital approach, and molecular electrostatic potential (MESP). The theoretical DFT calculation was performed using the DFT/B3LYP/6-31+G (d,p) basis set. Moreover, the biological reactivity of all the representative synthesized molecules was compared with the theoretically calculated quantum chemical descriptors and MESP 3D plots. We also investigated the drug-likeness characteristic and absorption, distribution, metabolism, excretion, and toxicity (ADMET) prediction. In general, our approach enables environmentally friendly access to 3-imidazolyl indole clubbed 1,2,3-triazole derivatives as prospective antiproliferative agents.

Pyrazolo - Pyrimidines as Targeted Anticancer Scaffolds - A Comprehensive Review

BACKGROUND

Globally, cancer is the leading cause of death, which causes 10 million deaths yearly. Clinically, several drugs are used in treatment but due to drug resistance and multidrug resistance, there occurs a failure in the cancer treatment.

OBJECTIVES

The present review article is a comprehensive review of pyrazole and pyrimidine hybrids as potential anticancer agents.

METHODS

The review comprises more than 60 research works done in this field. The efficiency of the reported pyrazolopyrimidine fused heterocyclic with their biological data and the influence of the structural aspects of the molecule have been discussed.

RESULTS

This review highlighted pyrazolo-pyrimidines as targeted anticancer agents with effect on multiple targets.

CONCLUSION

The review will be helpful for the researchers involved in targeted drugs for cancer therapy for designing new scaffolds with pyrazolo-pyrimidine moieties.

Targeting AKT2 in MDA-MB-231 Cells by Pyrazole Hybrids: Structural, Biological and Molecular Docking Studies

Pyrazolic hybrids appended with naphthalene, p-chlorobenzene, o-phenol and toluene have been synthesized using Claisen Schmidt condensation reaction of 1-benzyl-3,5-dimethyl-1H-pyrazole-4-carbaldehyde. All compounds were characterized by various spectroscopic techniques. Compound (E)-3-(1-benzyl-3,5-dimethyl-1H-pyrazol-4-yl)-1-(4-chlorophenyl)prop-2-en-1-one crystallizes in monoclinic crystal system with C2/c space group. These synthesized compounds were tested for cytotoxic activity and among these compounds 4b and 5a shows prominent cytotoxic activity against triple-negative breast cancer (TNBC) cells MDA-MB-231 with IC50 values 47.72 μM and 24.25 μM, respectively. Distinguishing morphological changes were noticed in MDA-MB-231 cells treated with pyrazole hybrids contributing to apoptosis action. To get more insight into cytotoxic activity, in silico molecular docking of these compounds were performed and the results suggested that (E)-3-(1-benzyl-3,5-dimethyl-1H-pyrazol-4-yl)-1-(p-tolyl)prop-2-en-1-one and 1-(1'-benzyl-5-(4-chlorophenyl)-3',5'-dimethyl-3,4-dihydro-1'H,2H-[3,4'-bipyrazol]-2-yl)ethan-1-one binds to the prominent domain of Akt2 indicating their potential ability as Akt2 inhibitor. Moreover, from in silico ADME studies clearly demonstrated that these compounds may be regarded as a drug candidate for sub-lingual absorption based on log p values (2.157-4.924). These compounds also show promising antitubercular activity. The overall results suggest that pyrazolic hybrids with substitution at less sterically hindered positions have appealing potent cytotoxic activity and antituberculosis activity due to which they may act as multidrug candidate.

The anti-breast cancer potential of indole/isatin hybrids

Breast cancer (BC) is one of the most prevalent malignancies and the major contributor to cancer mortality in women globally, with a high degree of heterogeneity and a dismal prognosis. As drug resistance is responsible for most BC fatalities and advanced BC is currently considered incurable, finding innovative anti-BC chemotherapeutics is urgently required. Indole and its analog isatin (indole-1H-2,3-dione) are prominent pharmacophores in the development of novel medications, and their derivatives exhibit strong anticancer activities, also against BC. In particular, indole/isatin hybrids exhibit significant potency against BC including multidrug-resistant forms and excellent selectivity by influencing a variety of biological targets associated with the disease, supplying helpful building blocks for the identification of potential new BC treatment options. This review includes articles from 2020 to the present and provides insights into the in vitro and in vivo anti-BC potential, molecular mechanisms, and structure-activity relationships (SARs) of indole/isatin hybrids that may be helpful in the development of innovative anti-BC chemotherapeutics.

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.

Synthesis, spectroscopic characterization, density functional theory study, antimicrobial and antioxidant activities of curcumin and alanine-curcumin Schiff base

In this work, a novel Schiff-base derived from curcumin and L-Alanine was synthesized under microwave conditions in excellent yield. The structural characterization has been carried out from their elemental analyses, FTIR, UV-Vis and 13C-NMR and 1H-NMR spectral techniques. The Schiff base (Cur-Ala) and curcumin (Cur) have been screened for their antimicrobial activity toward some pathogens clinically important microorganisms: Bacillus subtilis, Escherichia coli and Staphylococcus aureus, Aspergillus niger and Candida albicans. Result found that the Schiff base was more active than the curcumin. The antibacterial and antifungal activities of Cur-Ala can be attributed to its greatest dipole moment, as shown by theoretical calculations. Also, the antioxidant activity of Schiff base and curcumin were studied by DPPH, cupric ion reducing antioxidant capacity and o-phenanthroline techniques. Results indicate that Cur-Ala and Cur show more antioxidant activities than the standard antioxidants (BHT and BHA). Quantum chemical parameter calculations of Cur-Ala and Cur have been investigated by DFT using B3LYP/6-31G (d,p) basis set method to calculate the optimized structure, atomic charges, MESP, global reactivity descriptors and thermomolecular proprieties of both molecules.Communicated by Ramaswamy H. Sarma.

Recent Advances in the Development of Pyrazole Derivatives as Anticancer Agents

Pyrazole derivatives, as a class of heterocyclic compounds, possess unique chemical structures that confer them with a broad spectrum of pharmacological activities. They have been extensively explored for designing potent and selective anticancer agents. In recent years, numerous pyrazole derivatives have been synthesized and evaluated for their anticancer potential against various cancer cell lines. Structure-activity relationship studies have shown that appropriate substitution on different positions of the pyrazole ring can significantly enhance anticancer efficacy and tumor selectivity. It is noteworthy that many pyrazole derivatives have demonstrated multiple mechanisms of anticancer action by interacting with various targets including tubulin, EGFR, CDK, BTK, and DNA. Therefore, this review summarizes the current understanding on the structural features of pyrazole derivatives and their structure-activity relationships with different targets, aiming to facilitate the development of potential pyrazole-based anticancer drugs. We focus on the latest research advances in anticancer activities of pyrazole compounds reported from 2018 to present.

Molecular Docking Study of New Sorafenib Analogues as Platelet-Derived Growth Factor Receptor Inhibitors for the Treatment of Cancer

Cancer is a disease triggered by an uncontrolled growth of a group of cells usually from a single cell. Chemotherapy is a common and systematic therapy that involves the use of anticancer drugs also known as chemotherapeutical agents to treat cancer. Tyrosine kinases are a subset of protein kinases that are a family of over 90 enzymes that selectively phosphorylate tyrosine residues in various substrates. Receptors with internal tyrosine kinase activity mediate the actions of several growth factors, differentiation factors, and hormones, resulting in the reproduction and differentiation of the affected cells. In the fight against cancer, the platelet-derived growth factor receptor has emerged as a novel target via inhibition of this receptor resulting in the inhibition of tyrosine kinase cascade. Docking investigations were conducted using the Genetic Optimization for Ligand Docking (GOLD) Suite (v. 5.7.1) from the Cambridge Crystallographic Data Center. A high-definition X-ray crystallography of the platelet-derived growth factor protein [Protein Data Bank (PDB) ID 6JOL] was downloaded from the website PDB with a resolution of 2 A. Compounds II, III, VII, and VIII have greater binding energies than the GOLD standard medication sorafenib, which gives Piecewise Linear Potential (PLP) fitness value (85.3). Other ligands exhibit good inhibitory action and docking scores comparable to that of the reference ligand sorafenib.

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.

New Indazol-Pyrimidine-Based Derivatives as Selective Anticancer Agents: Design, Synthesis, and In Silico Studies

In this research study, the authors successfully synthesized potent new anticancer agents derived from indazol-pyrimidine. All the prepared compounds were tested for in vitro cell line inhibitory activity against three different cancerous cell lines. Results demonstrated that five of the novel compounds-4f, 4i, 4a, 4g, and 4d-possessed significant cytotoxic inhibitory activity against the MCF-7 cell line, with IC₅₀ values of 1.629, 1.841, 2.958, 4.680, and 4.798 μM, respectively, compared to the reference drug with an IC₅₀ value of 8.029 μM, thus demonstrating promising suppression power. Compounds 4i, 4g, 4e, 4d, and 4a showed effective cytotoxic activity stronger than the standard against Caco2 cells. Moreover, compounds 4a and 4i exhibited potent antiproliferative activity against the A549 cell line that was stronger than the reference drug. The most active products, 4f and 4i, werr e further examined for their mechanism of action. It turns out that they were capable of activating caspase-3/7 and, therefore, inducing apoptosis. However, produced a higher safety profile than the reference drug, towards the normal cells (MCF10a). Furthermore, the dynamic nature, binding interaction, and protein-ligand stability were explored through a Molecular Dynamics (MD) simulation study. Various analysis parameters (RMSD, RMSF, RoG, and SASA) from the MD simulation trajectory have suggested the stability of the compounds during the 20 ns MD simulation study. In silico ADMET results revealed that the synthesized compounds had low toxicity, good solubility, and an absorption profile since they met Lipinski's rule of five and Veber's rule. The present research highlights the potential of derivatives with indazole scaffolds bearing pyrimidine as a lead compound for designing anticancer agents.

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.

Design, synthesis and in vitro cytotoxicity evaluation of indolo-pyrazoles grafted with thiazolidinone as tubulin polymerization inhibitors

In the pursuit of potential and effective chemotherapeutic agents, a series of 2-((3-(indol-3-yl)-pyrazol-5-yl)imino)thiazolidin-4-ones was designed and synthesized, conjoining salient pharmacophoric properties for directing prominent cytotoxicity. The in vitro cytotoxicity evaluation revealed potent compounds with IC50 values <10 μM on tested human cancer cell lines. Compound 6c exhibited the highest cytotoxicity with an IC50 value of 3.46 μM against melanoma cancer cells (SK-MEL-28) and was highly cytospecific and selective towards cancer cells. The traditional apoptosis assays revealed morphological and nuclear alterations such as apoptotic body formation, condensed/horseshoe-shaped/fragmented/blebbing nuclei, and the generation of ROS. Flow cytometric analysis revealed effective early-stage apoptosis induction and cell-cycle arrest in the G2/M phase. In addition, the enzyme-based effect of 6c on tubulin showed the inhibition of tubulin polymerization (about 60% inhibition, IC50 was <1.73 μM). Moreover, molecular modeling studies affirmed the constant accommodation of compound 6c at the active pocket of tubulin, establishing many electrostatic and hydrophobic interactions with the active pocket's residues. The tubulin-6c complex was stable during the MD simulation for 50 ns with the recommended range of RMSD value (2-4 Å) for each pose.

Exploring novel derivatives of isatin-based Schiff bases as multi-target agents: design, synthesis, in vitro biological evaluation, and in silico ADMET analysis with molecular modeling simulations

Recently, scientists developed a powerful strategy called "one drug-multiple targets" to discover vital and unique therapies to fight the most challenging diseases. Novel derivatives of isatin-based Schiff bases 2-7 have been synthesized by the reaction of 3-hydrazino-isatin (1) with aryl aldehydes, hetero-aryl aldehydes, and dialdehydes. The structure of the synthesized derivatives was proved by physical and spectral analysis. Additionally, in vitro biological studies were performed, including antioxidant, anti-diabetic, anti-Alzheimer, and anti-arthritic activities. The four derivatives 3b, 5a, 5b, and 5c possess the highest activities. Among the four potent derivatives, compound 5a exhibited the highest antioxidant (TAC = 68.02 ± 0.15 mg gallic acid per g; IRP = 50.39 ± 0.11) and scavenging activities (ABTS = 53.98 ± 0.12% and DPPH = 8.65 ± 0.02 μg mL-1). Furthermore, compound 5a exhibited an α-amylase inhibitory percentage of 57.64 ± 0.13% near the acarbose (ACA = 69.11 ± 0.15%) and displayed inhibitor activity of the acetylcholinesterase (AChE) enzyme = 36.38 ± 0.08%. Moreover, our work extended to determining the anti-arthritic effect, and compound 5a revealed good inhibitor activities with very close values for proteinase denaturation (PDI) = 39.59 ± 0.09% and proteinase inhibition (PI) = 36.39 ± 0.08%, compared to diclofenac sodium PDI = 49.33 ± 0.11% and PI = 41.88 ± 0.09%. Additionally, the quantum chemical calculations, including HOMO, LUMO, and energy band gap were determined, and in silico ADMET properties were predicted, and their probability was recorded. Finally, molecular docking simulations were performed inside α-amylase and acetylcholinesterase enzymes.

In vitro enzymatic evaluation of some pyrazolo[1,5-a]pyrimidine derivatives: Design, synthesis, antioxidant, anti-diabetic, anti-Alzheimer, and anti-arthritic activities with molecular modeling simulation

The strategy of utilizing nitrogen compounds in various biological applications has recently emerged as a powerful approach to exploring novel classes of therapeutics to face the challenge of diseases. A series of pyrazolo[1,5-a]pyrimidine-based compounds 3a-l and 5a-f were prepared by the direct cyclo-condensation reaction of 5-amino-1H-pyrazoles 1a, b with 2-(arylidene)malononitriles and 3-(dimethylamino)-1-aryl-prop-2-en-1-ones, respectively. The structures of the new pyrazolo[1,5-a]pyrimidine compounds were confirmed via spectroscopic techniques. The in vitro biological activities of all pyrazolo[1,5-a]pyrimidines 3a-l and 5a-f were evaluated by assaying total antioxidant capacity, iron-reducing power, the scavenging activity against 1-diphenyl-2-picryl-hydrazyl (DPPH) and 2, 2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, anti-diabetic, anti-Alzheimer, and anti-arthritic biological activities. All compounds displayed good to potent bioactivity, and three compounds 3g, 3h, and 3l displayed the most active derivatives. Among these derivatives, compound 3l exhibited the highest antioxidant (total antioxidant capacity [TAC] = 83.09 mg gallic acid/g; iron-reducing power [IRP] = 47.93 µg/ml) and free radicals scavenging activities with (DPPH = 18.77 µg/ml; ABTS = 40.44%) compared with ascorbic acid (DPPH = 4.28 µg/ml; ABTS = 38.84%). Furthermore, compound 3l demonstrated the strongest inhibition of α-amylase with a percent inhibition of 72.91 ± 0.14 compared to acarbose = 67.92 ± 0.09%. Similarly, it displayed acetylcholinesterase inhibition of 62.80 ± 0.06%. However, compound 3i showed a significantly higher inhibition percentage for protein denaturation and proteinase at 20.66 ± 0.00 and 26.42 ± 0.06%, respectively. Additionally, some in silico ADMET properties were predicted and studied. Finally, molecular docking simulation was performed inside the active site of α-amylase and acetylcholinesterase to study their interactions.

Biologically Oriented Hybrids of Indole and Hydantoin Derivatives

Indoles and hydantoins are important heterocycles scaffolds which present in numerous bioactive compounds which possess various biological activities. Moreover, they are essential building blocks in organic synthesis, particularly for the preparation of important hybrid molecules. The series of hybrid compounds containing indoles and imidazolidin-2-one moiety with direct C-C bond were synthesized using an amidoalkylation one-pot reaction. All compounds were investigated as a growth regulator for germination, growth and development of wheat seeds (Triticum aestivum L). Their effect on drought resistance at very low concentrations (4 × 10^-5 M) was evaluated. The study highlighted identified the leading compounds, 3a and 3e, with higher growth-regulating activity than the indole-auxin analogues.

Synthesis, Characterization, DFT Mechanistic Study, Antimicrobial Activity, Molecular Modeling, and ADMET Properties of Novel Pyrazole-isoxazoline Hybrids

A series of new heterocycle hybrids incorporating pyrazole and isoxazoline rings was successfully synthesized, characterized, and evaluated for their antimicrobial responses. The synthesized compounds were obtained utilizing N-alkylation and 1,3-dipolar cycloaddition reactions, as well as their structures were established through spectroscopic methods and confirmed by mass spectrometry. To get more light on the regioselective synthesis of new hybrid compounds, mechanistic studies were performed using DFT calculations with B3LYP/6-31G(d,p) basis set. Additionally, the results of the preliminary screening indicate that some of the examined hybrids showed potent antimicrobial activity, compared to standard drugs. The results confirm that the antimicrobial activity is strongly dependent on the nature of the substituents linked pyrazole and isoxazoline rings. Furthermore, molecular docking studies were conducted to highlight the interaction modes between the investigated hybrid compounds and the Escherichia coli and Candida albicans receptors. Notably, the results demonstrate that the investigated compounds have strong protein binding affinities. The stability of the formed complexes by the binding between the hybrid compound 6c, and the target proteins was also confirmed using a 100 ns molecular dynamics simulation. Finally, the prediction of ADMET properties suggests that almost all hybrid compounds possess good pharmacokinetic profiles and no signs of observed toxicity, except for compounds 6e, 6f, and 6g.

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.

Regioselective Synthesis, Structural Characterization, and Antiproliferative Activity of Novel Tetra-Substituted Phenylaminopyrazole Derivatives

A small library of highly functionalized phenylaminopyrazoles, bearing different substituents at position 1, 3, and 4 of the pyrazole ring, was prepared by the one-pot condensation of active methylene reagents, phenylisothiocyanate, and substituted hydrazine (namely, methyl- and benzyl-hydrazine). The identified reaction conditions proved to be versatile and efficient. Furthermore, the evaluation of alternative stepwise protocols affected the chemo- and regio-selectivity outcome of the one-pot procedure. The chemical identities of two N-methyl pyrazole isomers, selected as prototypes of the whole series, were unambiguously identified by means of NMR and mass spectrometry studies. Additionally, semiempirical calculations provided a structural rationale for the different chromatographic behavior of the two isomers. The prepared tetra-substituted phenylaminopyrazoles were tested in cell-based assays on a panel of cancer and normal cell lines. The tested compounds did not show any cytotoxic effect on the selected cell lines, thus supporting their pharmaceutical potentials.

New 1,2,3-Triazole-Coumarin-Glycoside Hybrids and Their 1,2,4-Triazolyl Thioglycoside Analogs Targeting Mitochondria Apoptotic Pathway: Synthesis, Anticancer Activity and Docking Simulation

Toxicity and resistance to newly synthesized anticancer drugs represent a challenging phenomenon of intensified concern arising from variation in drug targets and consequently the prevalence of the latter concern requires further research. The current research reports the design, synthesis, and anticancer activity of new 1,2,3-triazole-coumarin-glycosyl hybrids and their 1,2,4-triazole thioglycosides as well as acyclic analogs. The cytotoxic activity of the synthesized products was studied against a panel of human cancer cell lines. Compounds 8, 10, 16 and 21 resulted in higher activities against different human cancer cells. The impact of the hybrid derivative 10 upon different apoptotic protein markers, including cytochrome c, Bcl-2, Bax, and caspase-7 along with its effect on the cell cycle was investigated. It revealed a mitochondria-apoptotic effect on MCF-7 cells and had the ability to upregulate pro-apoptotic Bax protein and downregulate anti-apoptotic Bcl-2 protein and thus implies the apoptotic fate of the cells. Furthermore, the inhibitory activities against EGFR, VEGFR-2 and CDK-2/cyclin A2 kinases for 8, 10 and 21 were studied to detect the mechanism of their high potency. The coumarin-triazole-glycosyl hybrids 8 and 10 illustrated excellent broad inhibitory activity (IC₅₀= 0.22 ± 0.01, 0.93 ± 0.42 and 0.24 ± 0.20 μM, respectively, for compound 8), (IC₅₀ = 0.12 ± 0.50, 0.79 ± 0.14 and 0.15± 0. 60 μM, respectively, for compound 10), in comparison with the reference drugs, erlotinib, sorafenib and roscovitine (IC₅₀ = 0.18 ± 0.05, 1.58 ± 0.11 and 0.46 ± 0.30 μM, respectively). In addition, the docking study was simulated to afford better rationalization and put insight into the binding affinity between the promising derivatives and their targeted enzymes and that might be used as an optimum lead for further modification in the anticancer field.

Therapeutic Applications of Self-assembled Indole-3-butanoyl-polyethylenimine Nanostructures

This study demonstrates the therapeutic potential of indole-3-butanoyl-polyethylenimine (IBP) nanostructures formed via self-assembly in aqueous system. Dynamic light scattering (DLS) analysis confirmed the formation of the nanostructures in the size range of ~ 194-331 nm. These nanostructures showed commendable antimicrobial activity against wide range of microbes including multi-drug resistant bacteria. Besides, appreciable antioxidant and anti-inflammatory activities were also observed. Results of cytotoxicity studies, performed on normal transformed human embryonic kidney (HEK 293) cells and human red blood cells (hRBCs), revealed almost non-toxic behavior of these nanostructures, however, remarkable toxicity on human breast cancer cells (MCF-7), human osteosarcoma cells (Mg63) and human liver cancer cells (HepG2) was observed. The pre-apoptotic and anti-proliferative activity of IBP nanostructures were confirmed by acridine orange/propidium iodide dual staining assay followed by confocal microscopy and scratch assay on Mg63 cells. Taken together, these results advocate the promising potential of the synthesized IBP nanostructures in the therapeutic applications.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-022-01015-y.

Recent Advances in Synthesis and Properties of Pyrazoles

Pyrazole-containing compounds represent one of the most influential families of N-heterocycles due to their proven applicability and versatility as synthetic intermediates in preparing relevant chemicals in biological, physical-chemical, material science, and industrial fields. Therefore, synthesizing structurally diverse pyrazole derivatives is highly desirable, and various researchers continue to focus on preparing this functional scaffold and finding new and improved applications; this review highlights some of the most recent and strategic examples regarding the synthesis and properties of different pyrazole derivatives, mainly reported from 2017–present. The discussion involves strategically functionalized rings (i.e., amines, carbaldehydes, halides, etc.) and their use in forming various fused systems, predominantly bicyclic cores with 5:6 fusion taking advantage of our experience in this field and the more recent investigations of our research group.

Concept of Hybrid Drugs and Recent Advancements in Anticancer Hybrids

Cancer is a complex disease, and its treatment is a big challenge, with variable efficacy of conventional anticancer drugs. A two-drug cocktail hybrid approach is a potential strategy in recent drug discovery that involves the combination of two drug pharmacophores into a single molecule. The hybrid molecule acts through distinct modes of action on several targets at a given time with more efficacy and less susceptibility to resistance. Thus, there is a huge scope for using hybrid compounds to tackle the present difficulties in cancer medicine. Recent work has applied this technique to uncover some interesting molecules with substantial anticancer properties. In this study, we report data on numerous promising hybrid anti-proliferative/anti-tumor agents developed over the previous 10 years (2011–2021). It includes quinazoline, indole, carbazole, pyrimidine, quinoline, quinone, imidazole, selenium, platinum, hydroxamic acid, ferrocene, curcumin, triazole, benzimidazole, isatin, pyrrolo benzodiazepine (PBD), chalcone, coumarin, nitrogen mustard, pyrazole, and pyridine-based anticancer hybrids produced via molecular hybridization techniques. Overall, this review offers a clear indication of the potential benefits of merging pharmacophoric subunits from multiple different known chemical prototypes to produce more potent and precise hybrid compounds. This provides valuable knowledge for researchers working on complex diseases such as cancer.

A new exploration toward adamantane derivatives as potential anti-MDR agents: Design, synthesis, antimicrobial, and radiosterilization activity as potential topoisomerase IV and DNA gyrase inhibitors

Developing novel antimicrobial agents has become a necessitate due to the increasing rate of microbial resistance to antibiotics. All the newly adamantane derivatives were evaluated for their antimicrobial activities against six MDR clinical pathogenic isolates. The results exhibited that 13 compounds have from potent to good activity. Among those, five derivatives (6, 7, 9, 14a, and 14b) displayed the potent activities against the different isolates tested (MIC < 0.25 µg/ml with bacteria and <8 µg/ml with fungi) compared with Ciprofloxacin (CIP) and Fluconazole (FCA). Additionally, the potent adamantanes showed bactericidal and fungicidal effects based on (MBCs and MFCs) and the time-kill assay. The most active adamantane derivatives 7 and 14b exhibited a synergistic effect of ΣFIC ≤ 0.5 with CIP and FCA against the bacterial and fungal isolates. Moreover, no antagonistic effect appeared for the tested derivatives. Additionally, the interaction of DNA gyrase and topoisomerase IV enzymes with the compounds 6, 7, 9, 14a, and 14b exhibited potent antimicrobial activity using in vitro biochemical assays and gel-based DNA-supercoiling inhibition method. The activity of DNA gyrase and topoisomerase IV enzymes showed inhibitory activity (IC₅₀ ) of 6.20 µM and 9.40 µM with compound 7 and 10.14 µM and 13.28 µM with compound 14b, respectively. Surprisingly, exposing compound 7 to gamma irradiation sterilized and increased its activity. Finally, the in-silico analysis predicted that the most active derivatives had good drug-likeness and safe properties. Besides, molecular docking and quantum chemical studies revealed several important interactions inside the active sites and showed the structural features necessary for activity.

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.

The Molecular Diversity of 1H-Indole-3-Carbaldehyde Derivatives and Their Role in Multicomponent Reactions

1H-Indole-3-carbaldehyde and related members of the indole family are ideal precursors for the synthesis of active molecules. 1H-Indole-3-carbaldehyde and its derivatives are essential and efficient chemical precursors for generating biologically active structures. Multicomponent reactions (MCRs) offer access to complex molecules. This review highlights the recent applications of 1H-indole-3-carbaldehyde in such inherently sustainable multicomponent reactions from the period, 2014 to 2021 and provides an overview of the field that awaits further exploitation in the assembly of pharmaceutically interesting scaffolds.