Discovery of 2-(2-aminopyrimidin-5-yl)-4-morpholino-N-(pyridin-3-yl)quinazolin-7-amines as novel PI3K/mTOR inhibitors and anticancer agents

Novel Pyrimidine-5-Carbonitriles as potential apoptotic and antiproliferative agents by dual inhibition of EGFRWT/T790M and PI3k enzymes; Design, Synthesis, biological Evaluation, and docking studies

A new series of 6-(4-fluorophenyl)-2-(methylthio) pyrimidine-5-carbonitrile derivatives were designed and synthesized as EGFR/PI3K dual inhibitors, and potential antiproliferative agents. The new 22 compounds were screened by DTP-NCI against all NCI60 cell lines. Almost all compounds showed cytotoxic activity. Compound 7c showed a promising antitumour activity on CNS cancer (SNB-75), and ovarian cancer (OVAR-4) with IC50 < 0.01, and 0.64 µM, respectively. Fortunately, 7c exhibited a better safety profile on normal cells (WI-38) than doxorubicin by 2.2-fold. Compound 7c displayed selective inhibitory activity on EGFRt790m over EGFRWT with IC50 = 0.08, and 0.13 µM, respectively, wherefore it might overcome EGFR-TKIs resistance. In addition to its remarkable inhibitory activity on all PI3K isoforms, specifically PI3K-δ with IC50 = 0.64 µM Compared with LY294002 IC50 = 7.6 µM. Compound 7c arrested the cell cycle of SNB-75 & OVAR-4 at the G0-G1 phase coupled with apoptosis induction. The western blotting analysis approved decreasing the expression level of p-AKT coupled with an increase in Casp3, Casp9, and BAX proteins in the SNB-75 & OVAR-4 after being treated with 7c which may support the suggested mechanism of action of 7c as EGFR/PI3K dual inhibitor. Physicochemical parameters were forecasted using SwissADME online tool. MD showed the interaction of 7c with the crucial amino acids of the active domain of both EGFR/PI3K which may explain its potent inhibitory activities. In vivo study disclosed a significant decrease in tumor weight and the number of nodules in the group of mice treated with 7c compared with the control group.

Design, synthesis and biological evaluation of novel morpholinopyrimidine-5-carbonitrile derivatives as dual PI3K/mTOR inhibitors

In this study, novel morpholinopyrimidine-5-carbonitriles were designed and synthesized as dual PI3K/mTOR inhibitors and apoptosis inducers. The integration of a heterocycle at position 2, with or without spacers, of the new key intermediate 2-hydrazinyl-6-morpholinopyrimidine-5-carbonitrile (5) yielded compounds 6-10, 11a-c and 12a-h. The National Cancer Institute (USA) tested all compounds for antiproliferative activity. Schiff bases, 12a-h analogs, were the most active ones. The most promising compounds 12b and 12d exhibited excellent antitumor activity against the leukemia SR cell line, which is the most sensitive cell line, with IC50 0.10 ± 0.01 and 0.09 ± 0.01 μM, respectively, along with significant effects on PI3Kα/PI3Kβ/PI3Kδ with IC50 values of 0.17 ± 0.01, 0.13 ± 0.01 and 0.76 ± 0.04 μM, respectively, for 12b and 1.27 ± 0.07, 3.20 ± 0.16 and 1.98 ± 0.11, respectively, for 12d compared to LY294002. Compared to Afinitor, these compounds inhibited mTOR with IC50 values of 0.83 ± 0.05 and 2.85 ± 0.17 μM, respectively. Annexin-V and propidium iodide (PI) double labeling showed that compounds 12b and 12d promote cytotoxic leukemia SR apoptosis. Compounds 12b and 12d also caused a G2/M cell cycle arrest in the leukaemia SR cell line. The findings of this study indicate that the highest effect was observed for 12b, which was supported by western blot and docking analysis.

Design, Synthesis, Molecular Docking Study and Biological Evaluation of Novel γ-Carboline Derivatives of Latrepirdine (Dimebon) as Potent Anticancer Agents

A series of novel γ-Carboline derivatives were designed and synthesized using the Suzuki coupling reaction to identify the leads for the activity against cancer. Interestingly, these compounds were tested for their anticancer activity against the cell lines, particularly human cancer cell lines MCF7 (breast), A549 (lung), SiHa (cervix), and Colo-205 (colon). Most of the γ-Carboline derivatives showed potent inhibitory activity in four cancer cell lines, according to in vitro anticancer activity screening. Two compounds, specifically LP-14 and LP-15, showed superior activity in cancer cell lines among the γ-Carboline derivatives from LP-1 to LP-16. Additionally, the compound LP-14, LP-15 and Etoposide carried out molecular docking studies on human topoisomerase II beta in complex with DNA and Etoposide (PDB ID: 3QX3). The docking studies' results showed that the derivative LP-15 was strongly bound with the receptor amino acid residues, including Glu477 and DC8 compared with the marked drug Etoposide.

Development of certain aminoquinazoline scaffolds as potential multitarget anticancer agents with apoptotic and anti-proliferative effects: Design, synthesis and biological evaluation

Newly designed 4 - aminoquinazoline derivatives (5a-f, 6a, b, 7, 8, 9, 10a-c, 11a, b, 12a, b and 13a, b) have been synthesized and evaluated for their potential multitarget anticancer activities, apoptotic and anti-proliferative effects. Thereupon, in vitro cytotoxic activities of all the synthesized compounds were screened against NCI 60 human cancer cell lines (nine subpanels) at NCI, USA. Successfully, 2-morpholino-N-(quinazolin-4-yl) acetohydrazide 5e was granted an NSC code, owing to its significant potency and broad spectrum of activity against various cancer cell lines; leukemia K-562, non-small cell lung cancer NCI-H522 cells, colon cancer SW-620, melanoma LOX IMVI, MALME-3M, renal cancer RXF 393, ACHN and breast cancer MDA-MB231/ATCC (GI% = 99.6, 161, 126.03, 90.22, 174.47, 139.7, 191 and 97, respectively). Compound 5e showed the best inhibitory activity (GI₅₀ = 1.3 µM) against melanoma LOX IMVI, when tested at five doses against NCI 60 cell lines. Furthermore, compound 5e showed comparable EGFR and CDK2 inhibitory activity results (IC₅₀ = 0.093 ± 0.006 μM and 0.143 ± 0.008 μM, respectively) to those of lapatinib and ribociclib (IC₅₀ = 0.03 ± 0.002 μM and 0.067 ± 0.004 μM, respectively). Western blotting analysis of compound 5e against melanoma LOX IMVI marked out significant reduced EGFR and CDK2 protein expression percentages, up to 32.97% and 34.09%, respectively, if compared to lapatinib (31.18%) and ribociclib (29.66%). Moreover, compound 5e caused clear cell cycle arrests at S phase of renal UO-31 cells and at G1 phase of both breast cancer MCF7 and ovarian cancer IGROV1, associated with remarkable increase of DNA content of the controls. In accordance, it demonstrated promising anti- proliferative and apoptotic activities, showing a significant increase in total apoptotic percentages of renal cancer UO-31, breast cancer MCF7 and ovarian IGROV1 cancer cell lines, if compared to the control untreated cells (from 1.79% to 46.72%, 2.19% to 39.02% and 1.66 to 42.51%, respectively). Molecular modelling and dynamic simulation study results supported the main objectives of the present work.

MSCs as Tumor-Specific Vectors for the Delivery of Anticancer Agents-A Potential Therapeutic Strategy in Cancer Diseases: Perspectives for Quinazoline Derivatives

Mesenchymal stem cells (MSCs) are considered to be a powerful tool in the treatment of various diseases. Scientists are particularly interested in the possibility of using MSCs in cancer therapy. The research carried out so far has shown that MSCs possess both potential pro-oncogenic and anti-oncogenic properties. It has been confirmed that MSCs can regulate tumor cell growth through a paracrine mechanism, and molecules secreted by MSCs can promote or block a variety of signaling pathways. These findings may be crucial in the development of new MSC-based cell therapeutic strategies. The abilities of MSCs such as tumor tropism, deep migration and immune evasion have evoked considerable interest in their use as tumor-specific vectors for small-molecule anticancer agents. Studies have shown that MSCs can be successfully loaded with chemotherapeutic drugs such as gemcitabine and paclitaxel, and can release them at the site of primary and metastatic neoplasms. The inhibitory effect of MSCs loaded with anti-cancer agents on the proliferation of cancer cells has also been observed. However, not all known chemotherapeutic agents can be used in this approach, mainly due to their cytotoxicity towards MSCs and insufficient loading and release capacity. Quinazoline derivatives appear to be an attractive choice for this therapeutic solution due to their biological and pharmacological properties. There are several quinazolines that have been approved for clinical use as anticancer drugs by the US Food and Drug Administration (FDA). It gives hope that the synthesis of new quinazoline derivatives and the development of methods of their application may contribute to the establishment of highly effective therapies for oncological patients. However, a deeper understanding of interactions between MSCs and tumor cells, and the exploration of the possibilities of using quinazoline derivatives in MSC-based therapy is necessary to achieve this goal. The aim of this review is to discuss the prospects for using MSC-based cell therapy in cancer treatment and the potential use of quinazolines in this procedure.

Quinazoline Derivatives as Potential Therapeutic Agents in Urinary Bladder Cancer Therapy

Cancer diseases remain major health problems in the world despite significant developments in diagnostic methods and medications. Many of the conventional therapies, however, have limitations due to multidrug resistance or severe side effects. Bladder cancer is a complex disorder, and can be classified according to its diverse genetic backgrounds and clinical features. A very promising direction in bladder cancer treatment is targeted therapy directed at specific molecular pathways. Derivatives of quinazolines constitute a large group of chemicals with a wide range of biological properties, and many quinazoline derivatives are approved for antitumor clinical use, e.g.,: erlotinib, gefitinib, afatinib, lapatinib, and vandetanib. The character of these depends mostly on the properties of the substituents and their presence and position on one of the cyclic compounds. Today, new quinazoline-based compounds are being designed and synthesized as potential drugs of anticancer potency against bladder cancers.

Medicinal attributes of pyridine scaffold as anticancer targeting agents

Background

The heterocyclic compounds particularly pyridine displayed clinical and biological implementation. Pyridine scaffolds have been detected in most relevant drug molecules that included pyridine provided a great possibility for treatment.

Main text

Pyridine-containing compounds have increasing importance for medicinal application as antiviral, anticholinesterase activities, antimalarial, antimicrobial, antidiabetic and anticancer. This has generated concern among researchers in synthesising a variety of pyridine derivatives.

Conclusion

This review focuses on different pyridine targets as anticancer and their pharmacophoric elements controlling its activity.

Discovery and SAR of Novel Disubstituted Quinazolines as Dual PI3Kalpha/mTOR Inhibitors Targeting Breast Cancer

The dual PI3Kα/ m TOR inhibitors represent a promising molecularly targeted therapy for cancer. Here, we documented the discovery of new 2,4-disubstituted quinazoline analogs as potent dual PI3Kα/sm TOR inhibitors. Our structure based chemistry endeavor yielded six excellent compounds 9e, 9f, 9g, 9k, 9m, and 9o with single/double digit nanomolar IC₅₀ values against both enzymes and acceptable aqueous solubility and stability to oxidative metabolism. One of those analogs, 9m, possessed a sulfonamide substituent, which has not been described for this chemical scaffold before. The short direct synthetic routes, structure-activity relationship, in vitro 2D cell culture viability assays against normal fibroblasts and 3 breast cancer cell lines, and in vitro 3D culture viability assay against MCF7 cells for this series are described.

Design, synthesis and biological evaluation of thieno[3,2-d]pyrimidine derivatives containing aroyl hydrazone or aryl hydrazide moieties for PI3K and mTOR dual inhibition

Recently, PI3K and mTOR have been regarded as promising targets for cancer treatment. Herein, we designed and synthesized four series of novel thieno[3,2-d]pyrimidine derivatives that containing aroyl hydrazone or aryl hydrazide moieties. These derivatives act as PI3K/mTOR dual inhibitors, suggesting that they can be used as cancer therapeutic agents. All compounds were tested for anti-proliferative activity against four cancer cell lines. The structure-activity relationship (SAR) studies were conducted by varying the moieties at the C-6 and C-2 positions of the thieno[3,2-d]pyrimidine core. It indicated that aryl hydrazide at C-6 position and 2-aminopyrimidine at C-2 position are optimal fragments. Compound 18b showed the most potent in vitro activity (PI3Kα IC₅₀ = 0.46 nM, mTOR IC₅₀ = 12 nM), as well as good inhibition against PC-3 (human prostate cancer), HCT-116 (human colorectal cancer), A549 (human lung adenocarcinoma) and MDA-MB-231 (human breast cancer) cell lines. Furthermore, Annexin-V and propidium iodide (PI) double staining confirmed that 18b induces apoptosis in cytotoxic HCT-116 cells. Moreover, the influence of 18b on cell cycle distribution was assessed on the HCT-116 cell line, and a cell cycle arrest was observed at the G₁/S phases.

Design, Synthesis, and Biological Evaluation of Novel Thienopyrimidine Derivatives as PI3Kα Inhibitors

Three series of novel thienopyrimidine derivatives 9a–l, 15a–l, and 18a–h were designed and synthesized, and their IC₅₀ values against four cancer cell lines HepG-2, A549, PC-3, and MCF-7 were evaluated. Most compounds show moderate cytotoxicity against the tested cancer cell lines. The most promising compound 9a showed moderate activity with IC₅₀ values of 12.32 ± 0.96, 11.30 ± 1.19, 14.69 ± 1.32, and 9.80 ± 0.93 µM, respectively. The inhibitory activities of compounds 9a and 15a against PI3Kα and mTOR kinase were further evaluated. Compound 9a exhibited PI3Kα kinase inhibitory activity with IC₅₀ of 9.47 ± 0.63 µM. In addition, docking studies of compounds 9a and 15a were also investigated.

Morpholine as a privileged structure: A review on the medicinal chemistry and pharmacological activity of morpholine containing bioactive molecules

Morpholine is a heterocycle featured in numerous approved and experimental drugs as well as bioactive molecules. It is often employed in the field of medicinal chemistry for its advantageous physicochemical, biological, and metabolic properties, as well as its facile synthetic routes. The morpholine ring is a versatile and readily accessible synthetic building block, it is easily introduced as an amine reagent or can be built according to a variety of available synthetic methodologies. This versatile scaffold, appropriately substituted, possesses a wide range of biological activities. There are many examples of molecular targets of morpholine bioactive in which the significant contribution of the morpholine moiety has been demonstrated; it is an integral component of the pharmacophore for certain enzyme active-site inhibitors whereas it bestows selective affinity for a wide range of receptors. A large body of in vivo studies has demonstrated morpholine's potential to not only increase potency but also provide compounds with desirable drug-like properties and improved pharamacokinetics. In this review we describe the medicinal chemistry/pharmacological activity of morpholine derivatives on various therapeutically related molecular targets, attempting to highlight the importance of the morpholine ring in drug design and development as well as to justify its classification as a privileged structure.

Revealing quinquennial anticancer journey of morpholine: A SAR based review

Morpholine, a six-membered heterocycle containing one nitrogen and one oxygen atom, is a moiety of great significance. It forms an important intermediate in many industrial and organic syntheses. Morpholine containing drugs are of high therapeutic value. Its wide array of pharmacological activity includes anti-diabetic, anti-emetic, growth stimulant, anti-depressant, bronchodilator and anticancer. Multi-drug resistance in cancer cases have emerged in the last few years and have led to the failure of many chemotherapeutic drugs. Newer treatment methods and drugs are being developed to overcome this problem. Target based drug discovery is an effective method to develop novel anticancer drugs. To develop newer drugs, previously reported work needs to be studied. Keeping this in mind, last five year's literature on morpholine used as anticancer agents has been reviewed and summarized in the paper herein.

Identification of novel PI3Kδ inhibitors by docking, ADMET prediction and molecular dynamics simulations

BACKGROUND

Phosphoinositide-3-kinase Delta (PI3Kδ) plays a key role in B-cell signal transduction and inhibition of PI3Kδ is confirmed to have clinical benefit in certain types of activation of B-cell malignancies. Virtual screening techniques have been used to discover new molecules for developing novel PI3Kδ inhibitors with little side effects.

METHOD

Computer aided drug design method were used to rapidly screen optimal PI3Kδ inhibitors from the Asinex database. Virtual screening based molecular docking was performed to find novel and potential lead compound targeting PI3Kδ, at first. Subsequently, drug likeness studies were carried out on the retrieved hits to evaluate and analyze their drug like properties such as absorption, distribution, metabolism, excretion, and toxicity (ADMET) for toxicity prediction. Three least toxic compounds were selected for the molecular dynamics (MD) simulations for 30 ns in order to validate its stability inside the active site of PI3Kδ receptor.

RESULTS

Based on the present in silico analysis, two molecules have been identified which occupied the same binding pocket confirming the selection of active site. ASN 16296138 (Glide score: -12.175 kcal/mol, cdocker binding energy: -42.975 kcal/mol and ΔG_bind value: -90.457 kcal/mol) and BAS 00227397 (Glide score: -10.988 kcal/mol, cdocker binding energy: -39.3376 kcal/mol and ΔG_bind value: -81.953 kcal/mol) showed docking affinities comparatively much stronger than those of already reported known inhibitors against PI3Kδ. These two ligand's behaviors also showed consistency during the simulation of protein-ligand complexes for 30000 ps respectively, which is indicative of its stability in the receptor pocket.

CONCLUSION

Compound ASN 16296138 and BAS 00227397 are potential candidates for experimental validation of biological activity against PI3Kδ in future drug discovery studies. This study smoothes the path for the development of novel leads with improved binding properties, high drug likeness, and low toxicity to humans for the treatment of cancer.

Mechanistic/mammalian target of rapamycin: Recent pathological aspects and inhibitors

The mechanistic/mammalian target of rapamycin (mTOR), also known as the mechanistic target of rapamycin, regulates many normal cell processes such as transcription, cell growth, and autophagy. Overstimulation of mTOR by its ligands, amino acids, sugars, and/or growth factors leads to physiological disorders, including cancer and neurodegenerative diseases. In this study, we reviewed the recent advances regarding the mechanism that involves mTOR in cancer, aging, and neurodegenerative diseases. The chemical and biological properties of recently reported small molecules that function as mTOR kinase inhibitors, including adenosine triphosphate-competitive inhibitors and dual mTOR/PI3K inhibitors, have also been reviewed. We focused on the reports published in the literature from 2012 to 2017.

Design, Synthesis and Biological Evaluation of Novel Phenylsulfonylurea Derivatives as PI3K/mTOR Dual Inhibitors

Five series of novel phenylsulfonylurea derivatives, 19a⁻d, 20a⁻d, 21a⁻d, 22a⁻d and 23a⁻d, bearing 4-phenylaminoquinoline scaffold were designed, synthesized and their IC₅₀ values against four cancer cell lines (HepG-2, A549, PC-3 and MCF-7) were evaluated. Most compounds showed moderate cytotoxicity activity against the cancer cell lines. Structure⁻activity relationships (SARs) and pharmacological results indicated that introduction of 4-aminoquinoline scaffold and phenylsulfonylurea scaffold were beneficial for anti-tumor activity. Moreover, para-methoxyl substitution of 4-anilino moiety and para-halogen substitution of phenylsulfonylurea have different impacts on different series of compounds. Furthermore, the micromolecule group substitution in the 6-position of the quinoline ring have a slight impact on the cellular activity of the target compounds.

Exploring the potential of newly synthesized 4-methyl-6-morpholino-pyrimidine derivatives as antiproliferative agents

A series of 4-methyl-6-morpholinopyrimidine derivatives were synthesised and found to prevent cancer cell proliferation by inducing apoptosis.

Discovery of 1-(3-aryl-4-chlorophenyl)-3-(p-aryl)urea derivatives against breast cancer by inhibiting PI3K/Akt/mTOR and Hedgehog signalings

PI3K/Akt/mTOR and hedgehog (Hh) signalings are two important pathways in breast cancer, which are usually connected with the drug resistance and cancer migration. Many studies indicated that PI3K/Akt/mTOR inhibitors and Hh inhibitors displayed synergistic effects, and the combination of the two signaling drugs could delay drug resistance and inhibit cancer migration in breast cancer. Therefore, the development of molecules simultaneously inhibiting these two pathways is urgent needed. Based on the structures of PI3K inhibitor buparlisib and Hh inhibitor vismodegib, a series of hybrid structures were designed and synthesized utilizing rational drug design and computer-based drug design. Several compounds displayed excellent antiproliferative activities against several breast cancer cell lines, including triple-negative breast cancer (TNBC) MDA-MB-231 cell. Further mechanistic studies demonstrated that the representative compound 9i could inhibit both PI3K/Akt/mTOR and hedgehog (Hh) signalings by inhibiting the phosphorylation of S6K and Akt as well as decreasing the SAG elevated expression of Gli1. Compound 9i could also induce apoptosis remarkably in T47D and MDA-MB-231 cells. In the transwell assay, 9i showed significant inhibition on the migration of MDA-MB-231.

An insight into the therapeutic potential of quinazoline derivatives as anticancer agents

Cancer is one of the major causes of worldwide human mortality. A wide range of cytotoxic drugs are available on the market, and several compounds are in different phases of clinical trials. Many studies suggest that these cytotoxic molecules are also associated with different types of adverse side effects; therefore researchers around the globe are involved in the development of more efficient and safer anticancer drugs. In recent years, quinazoline and its derivatives have been considered as a novel class of cancer chemotherapeutic agents that show promising activity against different tumors. The aim of this article is to comprehensively review and highlight the recent developments concerning the anticancer activity of quinazoline derivatives as well as offer perspectives on the development of novel quinazoline derivatives as anticancer agents in the near future.

Synthesis and biological evaluation of novel indole-pyrimidine hybrids bearing morpholine and thiomorpholine moieties

Based on our previous screening hit compound 1, a series of novel indole-pyrimidine hybrids possessing morpholine or thiomorpholine moiety were synthesized via an efficient one-pot multistep synthetic method. The antiproliferative activities of the synthesized compounds were evaluated in vitro against four cancer cell lines including HeLa, MDA-MB-231, MCF-7, and HCT116. The results revealed that most compounds possessed moderate to excellent potency. The IC₅₀ values of the most promising compound 15 are 0.29, 4.04, and 9.48 μM against MCF-7, HeLa, and HCT116 cell lines, respectively, which are 48.0, 4.9, and 1.8 folds more active than the lead compound 1. Moreover, fluorescence-activated cell sorting analysis revealed that compound 14 showing the highest activity against HeLa (IC₅₀ = 2.51 μM) displayed a significant effect on G₂/M cell-cycle arrest in a concentration-dependent manner in HeLa cell line. In addition, representative nine active hybrids were evaluated for tubulin polymerization inhibitory activities, and compound 15 exhibited the most potent anti-tubulin activity showing 42% inhibition at 10 μM. These preliminary results encourage a further investigation on indole-pyrimidine hybrids for the development of potent anticancer agents that inhibit tubulin polymerization.

Discovery of a series of N-(5-(quinolin-6-yl)pyridin-3-yl)benzenesulfonamides as PI3K/mTOR dual inhibitors

Recently, the phosphoinositide 3-kinase (PI3K) and mammalian target of rapamycin (mTOR) have been considered as promising targets for the treatment of cancer. Herein, we synthesized a series of N-(5-(quinolin-6-yl)pyridin-3-yl)benzenesulfonamides as novel PI3K/mTOR dual inhibitors for cancer therapy. In the biological evaluation, compound 17e was identified as a potent PI3K/mTOR dual inhibitor, which significantly inhibit Class I PI3Ks, mTOR and phosphorylation of pAkt(Ser473) at low nanomolar level. Moreover, 17e display high potency against PC-3 cells (IC50 = 80 nM) in the anti-proliferative assay, and showed acceptable pharmacokinetic properties in vivo.

Identification of 3-amidoquinoline derivatives as PI3K/mTOR dual inhibitors with potential for cancer therapy

A new series of 3-amidoquinoline derivatives were designed, synthesized and evaluated as PI3K/mTOR dual inhibitors.