Novel 4-arylaminoquinazoline derivatives with (E)-propen-1-yl moiety as potent EGFR inhibitors with enhanced antiproliferative activities against tumor cells

Medicinal chemistry applications of the Dimroth Rearrangement to the synthesis of biologically active compounds

The Dimroth Rearrangement (DR) is an isomerization process involving the translocation of exo- and endocyclic nitrogen atoms in heterocyclic systems via a ring opening, rotation, and ring closure mechanism. Originally discovered over 120 years ago, the mechanistic occurrence of the DR on multiple heterocycles has been widely studied, and its application to the synthesis of biologically active compounds is well documented, albeit on some occasions not directly referenced. A surprisingly high number of drug discovery programs take advantage of the DR for the synthesis of heterocycle-containing compounds, including 4-aminopyrimidines and 4-anilinoquinazolines. Evidence of the flexibility and valuable potential of the DR can be found in the use of this reaction in the manufacture processes of several active pharmaceutical ingredients (APIs) on a commercial scale, allowing a reduction in the manufacturing costs and the environmental burden of the synthetic routes. The aim of this review is to outline the generality and broad applicability of the DR to the synthesis of biologically active compounds and highlight the opportunities to utilize this tool more widely within the medicinal chemistry toolbox.

Design, Synthesis, Molecular Docking, and Biological Evaluation of Isatin-Based Fused Heterocycles As Epidermal Growth Factor Receptor Inhibitors

A series of isatin-based fused heterocycles were designed, synthesized, and evaluated for anticancer activity against four cancer cell lines: MCF-7, MDA-MB-231, A549, and HL-60. Among them, Q3 and T4 were found to be potent anticancer agents. Furthermore, two compounds Q3 and T4 were selected for epidermal growth factor receptor (EGFR) inhibitory activity. Two compounds Q3 and T4 were found to be most potent EGFR inhibitors with IC50 of 0.22 ± 0.10 and 0.19 ± 0.07 μM. The EGFR inhibitory activity of standard drug erlotinib was 0.08 ± 0.02 μM. Structural Activity Relationship studies showed that electronegative atoms were necessary for EGFR inhibitory potential. Finally, molecular docking studies were carried out to check the binding pattern of synthesized derivatives with the adenosine triphosphate (ATP) binding site of EGFR and results revealed that compounds Q3 (-9.2 kcal/mol) and T4 (-8.9 kcal/mol) exhibited better binding affinity than reference drug erlotinib (-7.3 kcal/mol).

Structure-Activity Relationship Studies Based on Quinazoline Derivatives as EGFR Kinase Inhibitors (2017-Present)

The epidermal growth factor receptor (EGFR) plays a critical role in the tumorigenesis of various forms of cancer. Targeting the mutant forms of EGFR has been identified as an attractive therapeutic approach and led to the approval of three generations of inhibitors. The quinazoline core has emerged as a favorable scaffold for the development of novel EGFR inhibitors due to increased affinity for the active site of EGFR kinase. Currently, there are five first-generation (gefitinib, erlotinib, lapatinib, vandetanib, and icotinib) and two second-generation (afatinib and dacomitinib) quinazoline-based EGFR inhibitors approved for the treatment of various types of cancers. The aim of this review is to outline the structural modulations favorable for the inhibitory activity toward both common mutant (del19 and L858R) and resistance-conferring mutant (T790M and C797S) EGFR forms, and provide an overview of the newly synthesized quinazoline derivatives as potentially competitive, covalent or allosteric inhibitors of EGFR.

Medicinal Chemistry of Quinazolines as Anticancer Agents Targeting Tyrosine Kinases

Cancer is a large group of diseases that can affect any organ or body tissue due to the abnormal cellular growth with the unknown reasons. Many of the existing chemotherapeutic agents are highly toxic with a low level of selectivity. Additionally, they lead to development of therapeutic resistance. Hence, the development of targeted chemotherapeutic agents with low side effects and high selectivity is required for cancer treatment. Quinazoline is a vital scaffold well-known to be linked with several biological activities. The anticancer activity is one of the prominent biological activities of this scaffold. Several established anticancer quinazolines work by different mechanisms on the various molecular targets. The aim of this review is to present different features of medicinal chemistry as drug design, structure activity relationship, and mode of action of some targeted anticancer quinazoline derivatives. It gives comprehensive attention on the chemotherapeutic activity of quinazolines in the viewpoint of drug discovery and its development. This review provides panoramic view to the medicinal chemists for supporting their efforts to design and synthesize novel quinazolines as targeted chemotherapeutic agents.

New application of novel tetrazine derivatives as potent VEGFR-2 kinase inhibitors and anti-cancer agents

Background: A novel series of s-tetrazine derivatives was designed as a new scaffold and synthesized efficiently as VEGFR-2 inhibitors for the first time. Methodology & results: The inhibitory activities of the new compounds were tested by MTT assay and enzyme assay, respectively. Western blot assay, cell apoptosis assay and cell migration assay were carried out to study the action mechanism of them. All the synthesized compounds showed evident VEGFR-2 inhibitory activities (IC₅₀ in the range of 88.53-257.55 nM). Compounds 23h, 25d, 26e and 27c showed excellent anti-proliferative activities against the four tested cell lines and were better than sorafenib basically. Conclusion: Compounds with good activities based on this novel scaffold can be screened successfully.

An appraisal of anticancer activity with structure-activity relationship of quinazoline and quinazolinone analogues through EGFR and VEGFR inhibition: A review

Cancer is one of the leading causes of death. Globally a huge number of deaths and new incidences are reported annually. Heterocyclic compounds have been proved to be very effective in the treatment of different types of cancer. Among different heterocyclic scaffolds, quinazoline and quinazolinone core were found versatile and interesting with many biological activities. In the discovery of novel anticancer agents, the Quinazoline core is very effective. The FDA has approved more than 20 drugs as an anticancer bearing quinazoline or quinazolinone core in the last two decades. One prime example is Dacomitinib, which was newly approved for non-small-cell lung carcinoma treatment in 2018. These drugs work by different pathways to prevent the spread of cancer cell progression, including inhibition of different kinases, tubulin, kinesin spindle protein, and so forth. This review presented recent developments of quinazoline/quinazolinone scaffold bearing derivatives as anticancer agents acting as epidermal growth factor receptor (EGFR) vascular endothelial growth factor receptor (VEGFR), and dual EGFR/VEGFR inhibitors.

Design, synthesis, biological evaluation and docking study of novel quinazoline derivatives as EGFR-TK inhibitors

Background: Quinazoline-based compounds have been proved effective in the treatment of cancers for years. Materials & methods: The structural features of several inhibitors of EGFR were integrated and quinazolines with a benzazepine moiety at the 4-position were constructed. Results: Most of the compounds exhibited excellent antitumor activities. Compound 33e showed excellent antitumor activities against the four tested cell lines (IC₅₀: 1.06-3.55 μM). The enzymatic, signaling pathways and apoptosis assay of 33e were subsequently carried out to study the action of the mechanism. Conclusion: Compound 33e with a benzazepine moiety at the 4-position can be screened in this study and provides useful information for the design of EGFR-T790M inhibitors, which deserve additional research.

Therapeutic progression of quinazolines as targeted chemotherapeutic agents

Presently cancer is a grave health issue with predominance beyond restrictions. It can affect any organ of the body. Most of the available chemotherapeutic drugs are highly toxic, not much selective and eventually lead to the development of resistance. Therefore, a target specific palliative approach for the treatment of cancer is required. Remarkable advancements in science have illuminated various molecular pathways responsible for cancer. This has resulted in abundant opportunities to develop targeted anticancer agents. Quinazoline nucleus is a privileged scaffold with significant diversified pharmacological activities. Numerous established anticancer quinazoline derivatives constitute a new class of chemotherapeutic agents which are found to act by inhibiting various protein kinases as well as other molecular targets. A recent update on various quinazoline derivatives acting on different types of molecular targets for the treatment of cancer has been compiled in this review. Brief SAR studies of quinazoline derivatives acting through different mechanisms of action have been highlighted. The comprehensive medicinal chemistry aspects of these agents in this review provide a panoramic view to the biologists as well as medicinal chemists working in this area and would assist them in their efforts to design and synthesize novel quinazoline based anticancer compounds.

Novel quinazoline-based EGFR kinase inhibitors: A review focussing on SAR and molecular docking studies (2015-2019)

The over expression of EGFR has been recognized as the driver mechanism in the occurrence and progression of carcinomas such as lung cancer, breast cancer, pancreatic cancer, etcetera. EGFR receptor was thus established as an important target for the management of solid tumors. The occurrence of resistance caused as a result of mutations in EGFR has presented a formidable challenge in the discovery of novel inhibitors of EGFR. This has resulted in the development of three generations of EGFR TKIs. Newer mutations like C797S cause failure of Osimertinib and other EGFR TKIs belonging to the third-generation caused by the development of resistance. In this review, we have summarized the work done in the last five years to overcome the limitations of currently marketed drugs, giving structural activity relationships of quinazoline-based lead compounds synthesized and tested recently. We have also highlighted the shortcomings of the currently used approaches and have provided guidance for circumventing these limitations. Our review would help medicinal chemists streamline and guide their efforts towards developing novel quinazoline-based EGFR inhibitors.

Synthesis and Antiproliferative Activities of Novel Substituted 5-Anilino-α-Glucofuranose Derivatives

In order to find novel antitumor candidate agents with high efficiency and low toxicity, 14 novel substituted 5-anilino-α-glucofuranose derivatives have been designed, synthesized and evaluated for antiproliferative activities in vitro. Their structures were characterized by NMR (¹ H and ¹³ C) and HR-MS, and configuration (R/S) at C(5) was identified by two-dimensional ¹ H,¹ H-NOESY-NMR spectrum. Their antiproliferative activities against human tumor cells were investigated by MTT assay. The results demonstrated that most of the synthesized compounds had antiproliferative effects comparable to the reference drugs gefitinib and lapatinib. In particular, (5R)-5-O-(3-chloro-4-{[5-(4-fluorophenyl)thiophen-2-yl]methyl}anilino)-5-deoxy-1,2-O-(1-methylethylidene)-α-glucofuranose (9da) showed the most potent antiproliferative effects against SW480, A431 and A549 cells, with IC₅₀ values of 8.57, 5.15 and 15.24 μm, respectively. This work suggested 5-anilino-α-glucofuranose as an antitumor core structure that may open a new way to develop more potent anti-cancer agents.

Design, synthesis and anticancer activity of novel valproic acid conjugates with improved histone deacetylase (HDAC) inhibitory activity

Twenty-five valproic acid conjugates have been designed and synthesized. All target compounds were explored for their in vitro anti-proliferative activities using the MTT-based assay against four human cancer cell lines includingliver (HePG2), colon (HCT116), breast (MCF7) and cervical (HeLa) carcinoma cell lines. Out of six valproic acid-amino acid conjugates 2a-f. Only cysteine containing conjugate 2f showed the significant activity (IC₅₀ 9.10 µM against HePG2 and 6.81 µM against HCT116). However conjugate 2j showed broad-spectrum antitumor activity against all cell lines tested. In addition, conjugates 4j and 4k which contains phenyl hydrazide and hydroxamic acid group, respectively, also showed broad spectrum activity. Furthermore, six compounds were screened for HDAC 1-9 isozymes inhibitory activities. Compounds 2j, 4j and 4k manifested a higher inhibitory activity more than valproic acid but less than SAHA. In addition, the in vivo antitumor screening of 2j, 4j and 4k was done and the results have shown that 2j, 4j and 4k, particularly 4j, showed a significant decrease in tumor size and presented a considerable decrease in viable EAC count. Docking study of selectedcompound 4j revealed that it can bind nicely to the binding pocket of HDAC 1, 2, 3, 4 and HDAC 8. The results suggest that compounds 2j, 4j and 4k, particularly 4j, may be promising lead candidates for the development of novel targeted anti-tumor drug potentially via inhibiting HDACs.

Novel 4-arylaminoquinazolines bearing N,N-diethyl(aminoethyl)amino moiety with antitumour activity as EGFRwt-TK inhibitor

Herein, four novel 4-arylaminoquinazoline derivatives with N,N-diethyl(aminoethyl)amino moiety were designed, synthesised and evaluated on biological activities in vitro. All synthesised compounds have inhibitory effects against tumour cells (SW480, A549, A431 and NCI-H1975). In particular, 4-(3-chloro-4-(3-fluorobenzyloxy)phenylamino)-6-(5-((N,N-diethyl(aminoethyl))aminomethyl)furan-2-yl)quinazoline (6a) and 6-(5-((N,N-diethylethyl)aminomethyl)furan-2-yl)-4-(4-(E)-(propen-1-yl)phenylamino)quinazoline (6d) were potent antitumour agents which showed high antiproliferative activities against tumour cells in vitro. Moreover, compound 6a could induce late apoptosis of A549 cells at high concentrations and arrest cell cycle of A549 cells in the G0/G1 phase at tested concentrations. Also, compound 6a could inhibit the activity of wild type epidermal growth factor receptor tyrosine kinase (EGFR^wt-TK) with IC₅₀ value of 15.60 nM. Molecular docking showed that compound 6a formed three hydrogen bonds with EGFR^wt-TK, while lapatinib formed only two hydrogen bonds with the receptor protein. It is believed that this work would be giving a reference for developing anti-cancer drugs targeted EGFR-TK.

Multifloroside Suppressing Proliferation and Colony Formation, Inducing S Cell Cycle Arrest, ROS Production, and Increasing MMP in Human Epidermoid Carcinoma Cell Lines A431

Multifloroside (4), together with 10-hydroxyoleoside 11-methyl ester (1), 10-hydroxyoleoside dimethyl ester (2), and 10-hydroxyligustroside (3), are all secoiridoids, which are naturally occurring compounds that possess a wide range of biological and pharmacological activities. However, the anti-cancer activity of 1–4 has not been evaluated yet. The objective of this work was to study the anti-cancer activities of 1–4 in the human epidermoid carcinoma cell lines A431 and the human non-small cell lung cancer (NSCLC) cell lines A549. The results indicate that 1–4 differ in potency in their ability to inhibit the proliferation of human A431 and A549 cells, and multifloroside (4) display the highest inhibitory activity against A431 cells. The structure-activity relationships suggest that the o-hydroxy-p-hydroxy-phenylethyl group may contribute to the anti-cancer activity against A431 cells. Multifloroside treatment can also inhibit cell colony formation, arrest the cell cycle in the S-phase, increase the levels of reactive-oxygen-species (ROS), and mitochondrial membrane potential (MMP), but it did not significantly induce cell apoptosis at low concentrations. The findings indicated that multifloroside (4) has the tendency to show selective anti-cancer effects in A431 cells, along with suppressing the colony formation, inducing S cell cycle arrest, ROS production, and increasing MMP.

Start Selective and Rigidify: The Discovery Path toward a Next Generation of EGFR Tyrosine Kinase Inhibitors

The epidermal growth factor receptor (EGFR), when carrying an activating mutation like del19 or L858R, acts as an oncogenic driver in a subset of lung tumors. While tumor responses to tyrosine kinase inhibitors (TKIs) are accompanied by marked tumor shrinkage, the response is usually not durable. Most patients relapse within two years of therapy often due to acquisition of an additional mutation in EGFR kinase domain that confers resistance to TKIs. Crucially, oncogenic EGFR harboring both resistance mutations, T790M and C797S, can no longer be inhibited by currently approved EGFR TKIs. Here, we describe the discovery of BI-4020, which is a noncovalent, wild-type EGFR sparing, macrocyclic TKI. BI-4020 potently inhibits the above-described EGFR variants and induces tumor regressions in a cross-resistant EGFR^{del19 T790M C797S} xenograft model. Key was the identification of a highly selective but moderately potent benzimidazole followed by complete rigidification of the molecule through macrocyclization.

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.

Inhibiting two cellular mutant epidermal growth factor receptor tyrosine kinases by addressing computationally assessed crystal ligand pockets

Aim: Blocking receptor tyrosine kinases is a useful strategy for inhibiting the overexpression of EGFR. However, the quality of crystal pocket is an essential issue for virtually identifying new leads for surviving resistance cancer cells. Results: With the examinating crystal pocket quality by the self-docking root-mean-square deviation (RMSD) calculation, we used the two best kinase pockets of mutant EGFR kinases, T790M/L858R and G719S, for virtual screening. After sorting all the docking poses of the 57,177 library compounds by consensus scores, three evidently blocked cellular EGFR phosphorylation in the H1975 and SW48 cell lines. Conclusion: The computationally assessed qualities of crystal pockets of crystal EGFR kinases can help identify new cellular active and target-specific ligands rapidly and at low cost.

6,7-Dimorpholinoalkoxy quinazoline derivatives as potent EGFR inhibitors with enhanced antiproliferative activities against tumor cells

A series of novel 6,7-dimorpholinoalkoxy quinazoline derivatives was designed, synthesized and evaluated as potent EGFR inhibitors. Most of synthesized derivatives exhibited moderate to excellent antiproliferative activities against five human tumor cell lines. Compound 8d displayed the most remarkable inhibitory activities against tumor cells expressing wild type (A431, A549 and SW480 cells) or mutant (HCC827 and NCI-H1975 cells) epidermal growth factor receptor (EGFR) (with IC₅₀ values in the range of 0.37-4.87 μM), as well as more potent inhibitory effects against recombinant EGFR tyrosine kinase (EGFR-TK, wt or T790M) (with the IC₅₀ values of 7.0 and 9.3 nM, respectively). Molecular docking showed that 8d can form four hydrogen bonds with EGFR, and two of them were located in the Asp855-Phe856-Gly857 (DFG) motif of EGFR. Meanwhile, 8d can significantly block EGF-induced EGFR activation and the phosphorylation of its downstream proteins such as Akt and Erk1/2 in human NSCLC cells. Also, 8d mediated cell apoptosis and the prolongation of cell cycle progression in G0/G1-phase in A549 cells. The work would have remarkable implications for further design and development of more potent EGFR tyrosine kinase inhibitors (TKIs).