Synthesis of 4,6-disubstituted pyrazolo[3,4-d]pyrimidine analogues: Cyclin-dependent kinase 2 (CDK2) inhibition, molecular docking and anticancer evaluation

Advances in synthesis and biological evaluation of CDK2 inhibitors for cancer therapy

One of the leading causes of mortality in the world is cancer. This disease occurs when responsible genes that regulate the cell cycle become inactive due to internal or external factors. Specifically, the G1/S and S/G2 transitions in the cell cycle are controlled by a protein called cyclin-dependent kinase 2 (CDK2). CDKs, which play a crucial role in managing the cell cycle, have been a wide area of research in cancer treatment. Over the past 11 years, significant research has been made in identifying potent, targeted, and efficient inhibitors of CDK2. In this summary, we have summarized recent developments in the synthesis and biological evaluation of CDK2 inhibitors.

Novel pyrazolo[3,4-d]pyrimidine derivatives: design, synthesis, anticancer evaluation, VEGFR-2 inhibition, and antiangiogenic activity

A novel series of 12 pyrazolo[3,4-d]pyrimidine derivatives were created and evaluated in vitro for their antiproliferative activity against the NCI 60 human tumor cell line panel. Compounds 12a-d displayed significant antitumor activity against MDA-MB-468 and T-47D (breast cancer cell lines), especially compound 12b, which exhibited the highest anticancer activity against MDA-MB-468 and T-47D cell lines with IC50 values of 3.343 ± 0.13 and 4.792 ± 0.21 μM, respectively compared to staurosporine with IC50 values of 6.358 ± 0.24 and 4.849 ± 0.22 μM. The most potent cytotoxic derivatives 12a-d were studied for their VEGFR-2 inhibitory activity to explore the mechanism of action of these substances. Compound 12b had potent activity against VEGFR-2 with an IC50 value of 0.063 ± 0.003 μM, compared to sunitinib with IC50 = 0.035 ± 0.012 μM. Moreover, there was an excellent reduction in HUVEC migratory potential that resulted in a significant disruption of wound healing patterns by 23% after 72 h of treatment with compound 12b. Cell cycle and apoptosis investigations showed that compound 12b could stop the cell cycle at the S phase and significantly increase total apoptosis in the MDA-MB-468 cell line by 18.98-fold compared to the control. Moreover, compound 12b increased the caspase-3 level in the MDA-MB-468 cell line by 7.32-fold as compared to the control.

Exploring cyclin-dependent kinase inhibitors: a comprehensive study in search of CDK-6 inhibitors using a pharmacophore modelling and dynamics approach

Cancer prevalence and resistance issues in cancer treatment are a significant public health concern globally. Among the existing strategies in cancer therapy, targeting cyclin-dependent kinases (CDKs), especially CDK-6 is found to be one of the most promising targets, as this enzyme plays a pivotal role in cell cycle stages and cell proliferation. Cell proliferation is the characteristic feature of cancer giving rise to solid tumours. Our research focuses on creating novel compounds, specifically, pyrazolopyrimidine fused azetidinones, using a groundbreaking molecular hybridization approach to target CDK-6. Through computational investigations, ligand-based pharmacophore modelling, pharmacokinetic studies (ADMET), molecular docking, and dynamics simulations, we identified 18 promising compounds. The pharmacophore model featured one aromatic hydrophobic centre (F1: Aro/Hyd) and two H-bond acceptors (F2 and F3: Acc). Molecular docking results showed favourable binding energies (-6.5 to -8.0 kcal mol-1) and effective hydrogen bonds and hydrophobic interactions. The designed compounds demonstrated good ADMET profiles. Specifically, B6 and B18 showed low energy conformation (-7.8 kcal and -7.6 kcal), providing insights into target inhibition compared to the standard drug Palbociclib. Extensive molecular dynamics simulations confirmed the stability of these derivatives. Throughout the 100 ns simulation, the ligand-protein complexes maintained structural stability, with acceptable RMSD values. These compounds hold promise as potential leads in cancer therapy.

Development of Novel Class of Phenylpyrazolo[3,4-d]pyrimidine-Based Analogs with Potent Anticancer Activity and Multitarget Enzyme Inhibition Supported by Docking Studies

Phenylpyrazolo[3,4-d]pyrimidine is considered a milestone scaffold known to possess various biological activities such as antiparasitic, antifungal, antimicrobial, and antiproliferative activities. In addition, the urgent need for selective and potent novel anticancer agents represents a major route in the drug discovery process. Herein, new aryl analogs were synthesized and evaluated for their anticancer effects on a panel of cancer cell lines: MCF-7, HCT116, and HePG-2. Some of these compounds showed potent cytotoxicity, with variable degrees of potency and cell line selectivity in antiproliferative assays with low resistance. As the analogs carry the pyrazolopyrimidine scaffold, which looks structurally very similar to tyrosine and receptor kinase inhibitors, the potent compounds were evaluated for their inhibitory effects on three essential cancer targets: EGFRWT, EGFRT790M, VGFR2, and Top-II. The data obtained revealed that most of these compounds were potent, with variable degrees of target selectivity and dual EGFR/VGFR2 inhibitors at the IC50 value range, i.e., 0.3-24 µM. Among these, compound 5i was the most potent non-selective dual EGFR/VGFR2 inhibitor, with inhibitory concentrations of 0.3 and 7.60 µM, respectively. When 5i was tested in an MCF-7 model, it effectively inhibited tumor growth, strongly induced cancer cell apoptosis, inhibited cell migration, and suppressed cell cycle progression leading to DNA fragmentation. Molecular docking studies were performed to explore the binding mode and mechanism of such compounds on protein targets and mapped with reference ligands. The results of our studies indicate that the newly discovered phenylpyrazolo[3,4-d]pyrimidine-based multitarget inhibitors have significant potential for anticancer treatment.

Synthesis of tricyclic and tetracyclic benzo[6,7]cycloheptane derivatives linked morpholine moiety as CDK2 inhibitors

With the aim of developing cyclin-dependent kinase 2 (CDK2) inhibitors with strong antibreast cancer efficacy, new tricyclic and tetracyclic benzo[6,7]cycloheptane derivatives were synthesized. The newly synthesized tri- and tetracyclic derivatives were achieved from the reaction of 4-(4-morpholin-4-yl-phenyl)-1,3,4,5,6,7-hexahydro-benzo[6,7]cyclohepta[1,2-d]pyrimidine-2-thione (5) with α-haloketone derivatives as hydrazonyl chlorides, phenacyl bromide derivatives, chloroacetone, and ethyl substituted acetate derivatives. The MCF-7 and MDA-MB-231 breast cancer cell lines were utilized to examine the anticancer properties. Compounds 5 and 8 were shown to be the most effective, with half-maximal inhibitory concentration (IC50 ) values between 5.73 and 9.11 µM, which are on the level with doxorubicin. Mechanistic studies showed that 5 and 8 caused tumor cell death by inducing apoptosis and they also produced cancer arrest in the S phase of the cell cycle. In addition, compounds 5 and 8 showed strong anti-CDK2 action (IC50  = 0.112 and 0.18 µM, respectively) comparable to roscovitine (IC50  = 0.127 µM). Moreover, the docking result demonstrated that derivatives 5 and 8 fit into the CDK2 active site in the proper orientation.

Dual targeting in prostate cancer with phytoconstituents as a potent lead: a computational approach for novel drug discovery

Prostate Cancer (PCa) is an abnormal cell growth within the prostate. This condition is the second most widespread malignancy in elderly males and one of the most frequently diagnosed life-threatening conditions. The Androgen receptor signaling pathway played a crucial role in the initiation and spread to increase the risk of PCa. Hence, targeting the AR receptor signaling pathway is a key strategy for a therapeutic plan for PCa. Our study focuses on recognizing potential inhibitors for dual targeting in PCa by using the in-silico approach. In this study, we target the two enzymes that are CYP17A1 (3RUK) and 5α-reductase (3G1R) responsible for PCa, with the help of phytoconstituents. The natural plant contains various phytochemical types produced from secondary metabolites and used as a medical treatment. The in-silico investigation of phytoconstituents and enzymes was done by approaching molecular docking, ADMET analysis, and high-level molecular dynamic simulation used to assess the stability and binding affinities of the protein-ligand complex. Some phytoconstituents, such as Peonidin, Pelargonidin, Malvidin and Berberine show complex has good molecular interaction with protein. The reliability of the docking scores was examined using a molecular dynamic simulation, which revealed that the complex remained stable throughout the simulation, which ranged from 0 to 200 ns. The selected hits may be effective against CYP17A1 (3RUK) and 5α-reductase (3G1R) (PCa) using a computer-aided drug design (CADD) method, which further enables researchers for upcoming in-vivo and in-vitro research, according to our in-silico approach.Communicated by Ramaswamy H. Sarma.

Synthesis, biological evaluation, and in silico studies of new CDK2 inhibitors based on pyrazolo[3,4-d]pyrimidine and pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine scaffold with apoptotic activity

Cyclin-dependent kinase inhibition is considered a promising target for cancer treatment for its crucial role in cell cycle regulation. Pyrazolo pyrimidine derivatives were well established for their antitumor activity via CDK2 inhibition. In this research, new series of pyrazolopyrimidine derivatives (4-15) was designed and synthesised as novel CDK2 inhibitors. The anti-proliferative activities against MCF-7, HCT-116, and HepG-2 were used to evaluate their anticancer activity as novel CDK2 inhibitors. Most of the compounds showed superior cytotoxic activity against MCF-7 and HCT-116 compared to Sorafenib. Only compounds 8, 14, and 15 showed potent activity against HepG-2. The CDK2/cyclin A2 enzyme inhibitory activity was tested for all synthesised compounds. Compound 15 showed the most significant inhibitory activity with IC₅₀ 0.061 ± 0.003 µM. It exerted remarkable alteration in Pre G1 and S phase cell cycle progression and caused apoptosis in HCT cells. In addition, the normal cell line cytotoxicity for compound 15 was assigned revealing low cytotoxic results in normal cells rather than cancer cells. Molecular docking was achieved on the designed compounds and confirmed the two essential hydrogen binding with Leu83 in CDK2 active site. In silico ADMET studies and drug-likeness showed proper pharmacokinetic properties which helped in structure requirements prediction for the observed antitumor activity.

Benzochromenopyrimidines: Synthesis, Antiproliferative Activity against Colorectal Cancer and Physicochemical Properties

Ten new differently substituted 3-benzyl-5-aryl-3,5-dihydro-4H-benzo[6,7]chromeno[2,3-d]pyrimidin-4,6,11-triones 3 were synthesized by a simple and cost-efficient procedure in a one-pot, three-component reaction from readily available ethyl 2-amino-4-aryl-5,10-dioxo-5,10-dihydro-4H-benzo[g]chromene-3-carboxylates, benzylamine and triethyl orthoformate under solvent- and catalyst-free conditions. All the new compounds were screened for their antiproliferative activity against two colorectal-cancer-cell lines. The results showed that the compounds 3-benzyl-5-phenyl-3,5-dihydro-4H-benzo[6,7]chromeno[2,3-d]pyrimidine-4,6,11-trione (3a) and 3-benzyl-5-(3-hydroxyphenyl)-3,5-dihydro-4H-benzo[6,7]chromeno[2,3-d]pyrimidine-4,6,11-trione (3g) exhibited the most potent balanced inhibitory activity against human LoVo and HCT-116 cancer cells.

Pyrazolopyrimidines as attractive pharmacophores in efficient drug design: A recent update

Among the menacing diseases, cancer needs the most attention as millions of people are affected by it worldwide. Genetic and environmental factors play a pivotal role in causing cancer. Although a wide range of underlying mechanisms of cancer has been discovered, efficient treatments have not been discovered to date. Additionally, diseases caused by microbes such as viruses, bacteria, protozoa, and so forth, persistently result in several deaths. Also, inflammation is a major factor that leads to several health issues. For decades, drug design has become a major part of drug discovery and development for curing various diseases. Among the large number of pharmacological agents that have been synthesized, only very few have emerged as efficient drug molecules. Most of them are heterocyclic compounds, which are promising candidates for the design of efficient drug molecules. Furthermore, fused heterocycles showed comparatively stronger pharmacological activities than monocyclic heterocycles. The literature reveals that pyrazolopyrimidines have outstanding biological activity. Hence, here, the diverse pharmacological activities shown by pyrazolopyrimidine derivatives reported in the last 5 years are collated and reviewed systematically. This review is classified into various sections focusing on anticancer, antimicrobial, anti-inflammatory, and enzyme inhibitors. Structure-activity relationships are discussed in brief, which will help researchers design potent pharmacological agents.

Drug Discovery of Plausible Lead Natural Compounds That Target the Insulin Signaling Pathway: Bioinformatics Approaches

The growing smooth talk in the field of natural compounds is due to the ancient and current interest in herbal medicine and their potentially positive effects on health. Dozens of antidiabetic natural compounds were reported and tested in vivo, in silico, and in vitro. The role of these natural compounds, their actions on the insulin signaling pathway, and the stimulation of the glucose transporter-4 (GLUT4) insulin-responsive translocation to the plasma membrane (PM) are all crucial in the treatment of diabetes and insulin resistance. In this review, we collected and summarized a group of available in vivo and in vitro studies which targeted isolated phytochemicals with possible antidiabetic activity. Moreover, the in silico docking of natural compounds with some of the insulin signaling cascade key proteins is also summarized based on the current literature. In this review, hundreds of recent studies on pure natural compounds that alleviate type II diabetes mellitus (type II DM) were revised. We focused on natural compounds that could potentially regulate blood glucose and stimulate GLUT4 translocation through the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway. On attempt to point out potential new natural antidiabetic compounds, this review also focuses on natural ingredients that were shown to interact with proteins in the insulin signaling pathway in silico, regardless of their in vitro/in vivo antidiabetic activity. We invite interested researchers to test these compounds as potential novel type II DM drugs and explore their therapeutic mechanisms.

Ru(III) complexes with pyrazolopyrimidines as anticancer agents: bioactivities and the underlying mechanisms

Three ruthenium(III) complexes with pyrazolopyrimidine [Ru(Lⁿ)(H₂O)Cl₃] (1-3, n = 1-3) were prepared and characterized. These Ru(III) compounds show strong cytotoxicity against six cancer cell lines and low toxicity to normal human liver cells. Particularly, they exhibited stronger cytotoxicity to SK-OV-3 cells than cisplatin. Mechanism studies revealed that complex 1 inhibited tumor cell invasion and suppressed cell proliferation, induced apoptosis by elevating the levels of intracellular ROS (reactive oxygen species) and free calcium (Ca²⁺), and reduced mitochondrial membrane potential (ΔΨ). It also activated the caspase cascade, accompanied with upregulation of cytochrome c, Bax, p53, Apaf-1 and downregulation of Bcl-2. Moreover, complex 1 caused cell cycle arrest at S phase by inhibiting the expression of CDC 25, cyclin A2 and CDK 2 proteins, and induced DNA damage by interacting with DNA and inhibiting the topoisomerase I enzyme. Complex 1 exhibited efficient in vivo anticancer activity in a model of SK-OV-3 tumor xenograft.

E Shahin M, Elsakka EGE, Mokhtar MM, Hegazy M, Hagras M, Mandour AA, Ismail NSM. Discovery of pyrazolo[3,4-d]pyrimidine and pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine derivatives as novel CDK2 inhibitors: synthesis, biological and molecular modeling investigations

CDK2 inhibition is an appealing target for cancer treatment that targets tumor cells in a selective manner. A new set of small molecules featuring the privileged pyrazolo[3,4-d]pyrimidine and pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine scaffolds (4–13) as well as the thioglycoside derivatives (14, 15) were designed, and synthesized as novel CDK2 targeting compounds. The growth of the three examined cell lines was significantly inhibited by most of the prepared compounds. Results revealed that most of the compounds showed superior cytotoxic activities against MCF-7 and HCT-116 with IC₅₀ range (45–97 nM) and (6–99 nM), respectively, and moderate activity against HepG-2 with IC₅₀ range of (48–90 nM) compared to sorafenib (IC₅₀: 144, 176 and 19 nM, respectively). Of these compounds, 14 & 15 showed the best cytotoxic activities against the three cell lines with IC₅₀ values of 45, 6, and 48 nM and 46, 7, and 48 nM against MCF-7, HCT-116 and HepG-2, respectively. Enzymatic inhibitory activity against CDK2/cyclin A2 was achieved for the most potent anti-proliferative compounds. Compounds 14, 13 and 15 revealed the most significant inhibitory activity with IC₅₀ values of 0.057 ± 0.003, 0.081 ± 0.004 and 0.119 ± 0.007 μM, respectively compared to sorafenib (0.184 ± 0.01 μM). Compound 14 displayed potent dual activity against the examined cell lines and CDK2, and was thus selected for further investigations. It exerted a significance alteration in cell cycle progression, in addition to apoptosis induction within HCT cells. Molecular docking simulation of the designed compounds confirmed the good fit into the CDK2 active site through the essential hydrogen bonding with Leu83. In silico ADMET studies and drug-likeness studies using a Boiled Egg chart showed suitable pharmacokinetic properties which helped in structure requirement prediction for the observed antitumor activity.

A new set of pyrazolo[3,4-d]pyrimidine and pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine scaffolds (4–13) as well as the thioglycoside derivatives (14, 15) were designed, and synthesized as novel CDK2 targeting compounds.

Pyrazolopyrimidines as anticancer agents: A review on structural and target-based approaches

Pyrazolopyrimidine scaffold is one of the privileged heterocycles in drug discovery. This scaffold produced numerous biological activities in which anticancer is important one. Previous studies showed its importance in interactions with various receptors such as growth factor receptor, TGFBR2 gene, CDK2/cyclin E and Abl kinase, adenosine receptor, calcium-dependent Protein Kinase, Pim-1 kinase, Potent Janus kinase 2, BTK kinase, P21-activated kinase 1, extracellular signal-regulated kinase 2, histone lysine demethylase and Human Kinesin-5. However, there is a need of numerous studies for the discovery of target based potential compounds. The structure activity relationship studies may help to explore the generation of potential compounds in short time period. Therefore, in the present review we tried to explore the structural aspects of Pyrazolopyrimidine with their structure activity relationship against various targets for the development of potential compounds. The current review is the compilation of significant advances made on Pyrazolopyrimidines reported between 2015 and 2020.

Advances in Pyrazole Based Scaffold as Cyclin-Dependent Kinase 2 Inhibitors for the Treatment of Cancer

The transformation of a normal cell into a tumor cell is one of the initial steps in cell cycle deregulation. The cell cycle is regulated by cyclin-dependent kinases (CDKs) that belong to the protein kinase family. CDK2 is an enchanting target for specific genotypes tumors since cyclin E is selective for CDK2 and the deregulation of specific cancer forms. Thus, CDKs inhibitor specifically CDK2/cyclin A-E has the potential to be a valid cancer target as per the currently undergoing clinical trials. Mostly pyrazole scaffolds have shown selectivity and potency for CDK2 inhibitors. This review demonstrates pyrazole and pyrazole fused with other heterocyclic rings for anti-proliferative activity. Based on the in vitro and molecular docking studies, the IC50 value of various hybrids is revealed to display the most potent analogs for CDK2 inhibition. Thus, the review emphasizes various lead analogs of pyrazole hybrids which can be found to be very potent and selective for anti-cancer drugs.

Synthesis of a new series of pyrazolo[1,5-a]pyrimidines as CDK2 inhibitors and anti-leukemia

Based on the structural study of previously known CDK2 inhibitors, a new series of pyrazolo[1,5-a]pyrimidine derivatives was designed and synthesized. The target compounds were biologically assessed as potent CDK2 inhibitors and promising anti-leukemia hits. The 7-(4-Bromo-phenyl)-3-(3-chloro/2-chloro-phenylazo)-pyrazolo[1,5-a]pyrimidin-2-ylamines 5 h and 5i revealed the best CDK2 inhibitory activity with comparable potency (IC₅₀ = 22 and 24 nM, respectively) to that of dinaciclib (IC₅₀ = 18 nM). Additionally, both analogues showed potent activities against CDK1, CDK5 and CDK9 at nanomolar concentrations (IC₅₀ = 28-80 nM). The anti-leukemia screening of the target compounds showed strong to moderate cytotoxicity against the used leukemia cell lines (MOLT-4 and HL-60). Compound 5 h inhibited MOLT-4 and HL-60 by 1.4 and 2.3 folds (IC₅₀ = 0.93 and 0.80 µM), respectively, compared to dinaciclib (IC₅₀ = 1.30 and 1.84 µM). Furthermore, compound 5i was comparable to dinaciclib against MOLT-4 and exhibited twice its activity against HL-60. Besides, the cytotoxicity of the promising analogues on normal human blood cells indicated the safety of 5h and 5i as compared to the reference dinaciclib. The pharmacokinetic properties of 5h and 5i were predicted using ADME calculations revealing good oral bioavailability and high GI absorption. The molecular docking simulations indicated, as expected, that the dinaciclib analogues can well-accommodate the CDK2 binding site, forming a variety of interactions.

Pharmacophore-linked pyrazolo[3,4-d]pyrimidines as EGFR-TK inhibitors: Synthesis, anticancer evaluation, pharmacokinetics, and in silico mechanistic studies

Targeting the epidermal growth factor receptors (EGFRs) with small inhibitor molecules has been validated as a potential therapeutic strategy in cancer therapy. Pyrazolo[3,4-d]pyrimidine is a versatile scaffold that has been exploited for developing potential anticancer agents. On the basis of fragment-based drug discovery, considering the essential pharmacophoric features of potent EGFR tyrosine kinase (TK) inhibitors, herein, we report the design and synthesis of new hybrid molecules of the pyrazolo[3,4-d]pyrimidine scaffold linked with diverse pharmacophoric fragments with reported anticancer potential. These fragments include hydrazone, indoline-2-one, phthalimide, thiourea, oxadiazole, pyrazole, and dihydropyrazole. The synthesized molecules were evaluated for their anticancer activity against the human breast cancer cell line, MCF-7. The obtained results revealed comparable antitumor activity with that of the reference drugs doxorubicin and toceranib. Docking studies were performed along with EGFR-TK and ADMET profiling studies. The results of the docking studies showed the ability of the designed compounds to interact with key residues of the EGFR-TK through a number of covalent and noncovalent interactions. The obtained activity of compound 25 (IC50  = 2.89 µM) suggested that it may serve as a lead for further optimization and drug development.

Novel thiomorpholine tethered isatin hydrazones as potential inhibitors of resistant Mycobacterium tuberculosis

Novel chemotherapeutic agents against multidrug resistant-tuberculosis (MDR-TB) are urgently needed at this juncture to save the life of TB-infected patients. In this work, we have synthesized and characterized novel isatin hydrazones 4(a-o) and their thiomorpholine tethered analogues 5(a-o). All the synthesized compounds were initially screened for their anti-mycobacterial activity against the H₃₇Rv strain of Mycobacterium tuberculosis (MTB) under level-I testing. Remarkably, five compounds 4f, 4h, 4n, 5f and 5m (IC₅₀ = 1.9 µM to 9.8 µM) were found to be most active, with 4f (IC₅₀ = 1.9 µM) indicating highest inhibition of H₃₇Rv. These compounds were further evaluated at level-II testing against the five drug-resistant strains such as isoniazid-resistant strains (INH-R1 and INH-R2), rifampicin-resistant strains (RIF-R1 and RIF-R2) and fluoroquinolone-resistant strain (FQ-R1) of MTB. Interestingly, 4f and 5f emerged as the most potent compounds with IC₅₀ of 3.6 µM and 1.9 µM against RIF-R1 MTB strain, followed by INH-R1 MTB strain with IC₅₀ of 3.5 µM and 3.4 µM, respectively. Against FQ-R1 MTB strain, the lead compounds 4f and 5f displayed excellent inhibition at IC₅₀ 5.9 µM and 4.9 µM, respectively indicating broad-spectrum of activity. Further, molecular docking, ADME pharmacokinetic and molecular dynamics simulations of the compounds were performed against the DNA gyrase B and obtained encouraging results.

Pyrimidine: a review on anticancer activity with key emphasis on SAR

Background

Cancer is a global health challenge, it impacts the quality of life and its treatment is associated with several side effects. Resistance of the cancer cells to the existing drugs has led to search for novel anticancer agents. Pyrimidine, a privileged scaffold, is part of living organisms and plays vital role in various biological procedures as well as in cancer pathogenesis. Due to resemblance in structure with the nucleotide base pair of DNA and RNA, it is recognized as valuable compound in the treatment of cancer.

Main text

Many novel pyrimidine derivatives have been designed and developed for their anticancer activity in the last few years. The present review aims to focus on the structure activity relationship (SAR) of pyrimidine derivatives as anticancer agent from the last decade.

Conclusion

This review intends to assist in the development of more potent and efficacious anticancer drugs with pyrimidine scaffold.

Graphical abstract

Pyrazole[3,4-d]pyrimidine derivatives loaded into halloysite as potential CDK inhibitors

Uncontrolled cell proliferation is a hallmark of cancer as a result of rapid and deregulated progression through the cell cycle. The inhibition of cyclin-dependent kinases (CDKs) activities is a promising therapeutic strategy to block cell cycle of tumor cells. In this work we reported a new example of nanocomposites based on halloysite nanotubes (HNTs)/pyrazolo[3,4-d]pyrimidine derivatives (Si306 and Si113) as anticancer agents and CDK inhibitors. HNTs/Si306 and HNTs/Si113 nanocomposites were synthesized and characterized. The release kinetics were also investigated. Antitumoral activity was evaluated on three cancer cell lines (HeLa, MDA-MB-231 and HCT116) and the effects on cell cycle arrest in HCT116 cells were evaluated. Finally, molecular dynamics simulations were performed of the complexes between Si113 or Si306 and the active site of both CDK 1 and 2.

In silico approach of naringin as potent phosphatase and tensin homolog (PTEN) protein agonist against prostate cancer

Prostate cancer (PC) is one of the major impediments affecting men, which leads approximately 31,620 deaths in both developing and developed countries. Although some chemotherapy drugs have been reported for prostate cancer, they are not effective due to the lack of safety, efficacy and low selectivity. Hence, the novel alternative anticancer agents with remarkable effect are highly appreciable. Natural plants contain several bio-active compounds which have been traditionally used for the various medical treatments. Particularly, naringin is a natural bio-active compound commonly found in the citrus fruits, which have shown numerous biological activities. Phosphatase and tensin homolog (PTEN) is a tumor suppressor gene, which activates both lipid phosphates and protein phosphates. The PTEN gene is negative regulator of PI3K/AKT/mTOR pathways, since, this signaling pathway play an essential role in the cell survival, proliferation and migration. In the present in silico investigation, structure based virtual screening, molecular docking, molecular dynamics simulation and Adsorption, Distribution, Metabolism, Excretion (ADME) prediction were employed to determine the binding affinity, stability and drug likeness properties of top ranked screened compounds and naringin, respectively. The results revealed that the complex has good molecular interactions, binding stability (peak between 0.3 and 0.4 nm) and no violations in the Lipinski Rule of 5 in naringin, but the screened compounds violated the drug likeness properties. From the in silico analyses, it is identified that naringin compound might assist in the development of novel therapeutic candidate against prostate cancer.Communicated by Ramaswamy H. Sarma.

Recent developments in anticancer kinase inhibitors based on the pyrazolo[3,4-d]pyrimidine scaffold

Pyrazolo[3,4-d]pyrimidines have become of significant interest for the medicinal chemistry community as a privileged scaffold for the development of kinase inhibitors to treat a range of diseases, including cancer. This fused nitrogen-containing heterocycle is an isostere of the adenine ring of ATP, allowing the molecules to mimic hinge region binding interactions in kinase active sites. Similarities in kinase ATP sites can be exploited to direct the activity and selectivity of pyrazolo[3,4-d]pyrimidines to multiple oncogenic targets through focussed chemical modification. As a result, pharma and academic efforts have succeeded in progressing several pyrazolo[3,4-d]pyrimidines to clinical trials, including the BTK inhibitor ibrutinib, which has been approved for the treatment of several B-cell cancers. In this review, we examine the pyrazolo[3,4-d]pyrimidines currently in clinical trials for oncology patients, as well as those published in the literature during the last 5 years for different anticancer indications.

Synthesis, cytotoxicity of some pyrazoles and pyrazolo[1,5-a]pyrimidines bearing benzothiazole moiety and investigation of their mechanism of action

A novel series of pyrazoles and pyrazolo[1,5-a]pyrimidines bearing benzothiazole moiety were designed and synthesized. Chemical structures were confirmed by spectral data and elemental analyses. Nine compounds were selected and screened for their cytotoxic activity at the National Cancer Institute (NCI), USA against 60 cancer cell lines in a single dose assay. Compounds 4 and 5 exerted the most potent growth inhibitory activity against most cancer cell lines with growth inhibition (GI%) ranges from 44.86% to 84.59% and 31.20% to 52.36%, respectively. Consequently, they were further investigated through IC₅₀ determination using five dose MTT colorimetric assay against three sensitive cell lines, leukemia CCRF-CEM, non-small cell lung cancer HOP-92 and liver cancer Hep-G2. Compound 4 exhibited potent cytotoxic activity against the three tested cell lines with IC₅₀ 16.34, 3.45 and 7.79 μM, respectively representing half potency, 3.5 folds potency and nearly equipotent to roscovitine. To investigate its mechanism of action, cell cycle analysis of compound 4 was conducted and showed that it induced cell cycle arrest at G2/M phase and apoptosis in HOP-92 cells. In correlation with the previous results, caspase-3 activation was tested and illustrated elevation in its concentration by nearly 14 folds than control. Besides, enzyme inhibition assay of compound 4 was evaluated towards two common antitumor targets namely KDM1 and CDK1 showing significant inhibitory activity with IC₅₀ 0.096 and 0.078 μM, respectively.