Discovery of 1-substituted benzyl-quinazoline-2,4(1H,3H)-dione derivatives as novel poly(ADP-ribose)polymerase-1 inhibitors

Quinazoline Derivatives as Targeted Chemotherapeutic Agents

Most of the current chemotherapeutic medications are extremely toxic, exhibit little selectivity, and contribute to the emergence of treatment resistance. Consequently, the discovery of targeted chemotherapy drugs with high selectivity and low side effects is necessary for cancer treatment. The quinazoline system has a broad range and a long history of biological activities. Numerous quinazoline derivatives have been used to treat different types of cancer by working on various molecular targets. This review presents various chemical information, including molecular structure, design, and biological activity of some reported quinazolines that function by inhibiting four types of important molecular targets: dihydrofolate reductase, breast cancer resistant protein, poly-(ADP-ribose)-polymerase, and tubulin polymerization.

Small molecule tractable PARP inhibitors: Scaffold construction approaches, mechanistic insights and structure activity relationship

Diverse drug design strategies viz. molecular hybridization, substituent installation, scaffold hopping, isosteric replacement, high-throughput screening, induction and separation of chirality, structure modifications of phytoconstituents and use of structural templates have been exhaustively leveraged in the last decade to load the chemical toolbox of PARP inhibitors. Resultantly, numerous promising scaffolds have been pinpointed that in turn have led to the resuscitation of the credence to PARP inhibitors as cancer therapeutics. This review briefly presents the physiological functions of PARPs, the pharmacokinetics, and pharmacodynamics, and the interaction profiles of FDA-approved PARP inhibitors. Comprehensively covered is the section on the drug design strategies employed by drug discovery enthusiasts for furnishing PARP inhibitors. The impact of structural variations in the template of designed scaffolds on enzymatic and cellular activity (structure-activity relationship studies) has been discussed. The insights gained through the biological evaluation such as profiling of physicochemical properties andin vitroADME properties, PK assessments, and high-dose pharmacology are covered.

Discovery of Quinazoline-2,4(1H,3H)-dione Derivatives Containing a Piperizinone Moiety as Potent PARP-1/2 Inhibitors─Design, Synthesis, In Vivo Antitumor Activity, and X-ray Crystal Structure Analysis

PARP-1/2 inhibitors have become an important therapeutic strategy for the treatment of HR-deficient tumors. However, discovery of new inhibitors with an improved and distinct pharmacological file still need enormous explorations. Herein, a series of novel highly potent PARP-1/2 inhibitors bearing an N-substituted piperazinone moiety were achieved. In particular, Cpd36 was identified as a distinct PARP inhibitor, showing remarkable enzymatic activity not only toward PARP-1 (IC50 = 0.94 nM) and PARP-2 (IC50 = 0.87 nM) but also toward PARP-7 (IC50 = 0.21 nM), as well as high selectivity over other PARP isoforms. Furthermore, Cpd36 was orally bioavailable and significantly repressed the tumor growth in both breast cancer and prostate cancer xenograft model. The crystal structures of Cpd36 within PARP-1 and PARP-2 together with the predicted binding mode within PARP-7 revealed its binding features and provided insightful information for further developing highly potent and selective PARP-1 and/or PARP-7 inhibitors.

Prudent tactics to sail the boat of PARP inhibitors as therapeutics for diverse malignancies

INTRODUCTION

PARP inhibitors block the DNA-repairing mechanism of PARP and represent a promising class of anti-cancer therapy. The last decade has witnessed FDA approvals of several PARP inhibitors, with some undergoing advanced-stage clinical investigation. Medicinal chemists have invested much effort to expand the structure pool of PARP inhibitors. Issues associated with the use of PARP inhibitors that make their standing disconcerting in the pharmaceutical sector have been addressed via the design of new structural assemblages.

AREA COVERED

In this review, the authors present a detailed account of the medicinal chemistry campaigns conducted in the recent past for the construction of PARP1/PARP2 inhibitors, PARP1 biased inhibitors, and PARP targeting bifunctional inhibitors as well as PARP targeting degraders (PROTACs). Limitations associated with FDA-approved PARP inhibitors and strategies to outwit the limitations are also discussed.

EXPERT OPINION

The PARP inhibitory field has been rejuvenated with numerous tractable entries in the last decade. With numerous magic bullets in hand coupled with unfolded tactics to outwit the notoriety of cancer cells developing resistance toward PARP inhibitors, the dominance of PARP inhibitors as a sagacious option of targeted therapy is highly likely to be witnessed soon.

Discovery of fluorinated 2‑Styryl 4(3H)-quinazolinone as potential therapeutic hit for oral cancer

Oral squamous cell carcinoma (OSCC) is the most common malignant epithelial neoplasm, affects the mouth and throat, and accounts for 90 % of oral cancers. Considering the associated morbidity with neck dissections and the limitation of existing therapeutic agents, the discovery and development of new anticancer drugs/drug candidates for oral cancer treatment are of the utmost need. In this context, reported here is the identification of fluorinated 2‑styryl 4(3H)-quinazolinone as a promising hit for oral cancer. Preliminary studies indicate that the compound blocks the transition of G1 to S phase, thereby leading to arrest in the G1/S phase. Subsequent RNA-seq analysis revealed that the compound induces the activation of molecular pathways involved in apoptosis (such as TNF signalling through NF-κB, p53 pathways) and cell differentiation and suppresses the pathways of cellular growth and development (such as KRAS signaling) in CAL-27 cancer cells. It is noted that identified hit complies with a favorable range of ADME properties as per the computational analysis.

Multi-therapies Based on PARP Inhibition: Potential Therapeutic Approaches for Cancer Treatment

The nuclear enzymes called poly(ADP-ribose)polymerases (PARPs) are known to catalyze the process of PARylation, which plays a vital role in various cellular functions. They have become important targets for the discovery of novel antitumor drugs since their inhibition can induce significant lethality in tumor cells. Therefore, researchers all over the world have been focusing on developing novel and potent PARP inhibitors for cancer therapy. Studies have shown that PARP inhibitors and other antitumor agents, such as EZH2 and EGFR inhibitors, play a synergistic role in cancer cells. The combined inhibition of PARP and the targets with synergistic effects may provide a rational strategy to improve the effectiveness of current anticancer regimens. In this Perspective, we sum up the recent advance of PARP-targeted agents, including single-target inhibitors/degraders and dual-target inhibitors/degraders, discuss the fundamental theory of developing these dual-target agents, and give insight into the corresponding structure-activity relationships of these agents.

A Novel PARP Inhibitor YHP-836 For the Treatment of BRCA-Deficiency Cancers

PARP inhibitors have clinically demonstrated good antitumor activity in patients with BRCA mutations. Here, we described YHP-836, a novel PARP inhibitor, YHP-836 demonstrated excellent inhibitory activity for both PARP1 and PARP2 enzymes. It also allosterically regulated PARP1 and PARP2 via DNA trapping. YHP-836 showed cytotoxicity in tumor cell lines with BRCA mutations and induced cell cycle arrest in the G2/M phase. YHP-836 also sensitized tumor cells to chemotherapy agents in vitro. Oral administration of YHP-836 elicited remarkable antitumor activity either as a single agent or in combination with chemotherapy agents in vivo. These results indicated that YHP-836 is a well-defined PARP inhibitor.

Design and synthesis of novel quinazolinone–chalcone hybrids as potential apoptotic candidates targeting caspase-3 and PARP-1: in vitro, molecular docking, and SAR studies

Novel quinazolinone–chalcone hybrids as potential apoptotic candidates targeting caspase-3 and PARP-1.

Discovery of Quinazoline-2,4(1H,3H)-dione Derivatives Containing 3-Substituted Piperizines as Potent PARP-1/2 Inhibitors─Design, Synthesis, In Vivo Antitumor Activity, and X-ray Crystal Structure Analysis

Inhibiting PARP-1/2 offered an important arsenal for cancer treatments via interfering with DNA repair of cancer cells. Novel PARP-1/2 inhibitors were designed by capitalizing on methyl- or ethyl-substituted piperizine ring to capture the characteristics of adenine-ribose binding site (AD site), and their unique binding features were revealed by the cocrystal structures of compounds 4 and 6 in PARP-1. The investigation on structure-activity relationship resulted in compounds 24 and 32 with high enzymatic potency, binding selectivity, and significantly longer residence time for PARP-1 over PARP-2 (compound 24, PARP-1: IC₅₀ = 0.51 nM, PARP-2: IC₅₀ = 23.11 nM; compound 32, PARP-1: IC₅₀ = 1.31 nM, PARP-2: IC₅₀ = 15.63 nM). Furthermore, compound 24 was determined to be an attractive candidate molecule, which possessed an acceptable pharmacokinetic profile and produced remarkable antitumor activity in both breast cancer xenograft model and glioblastoma orthotopic model in mice, either alone or in combination treatment.

Targeting SARS-CoV-2 Polymerase with New Nucleoside Analogues

Despite the fact that COVID-19 vaccines are already available on the market, there have not been any effective FDA-approved drugs to treat this disease. There are several already known drugs that through drug repositioning have shown an inhibitory activity against SARS-CoV-2 RNA-dependent RNA polymerase. These drugs are included in the family of nucleoside analogues. In our efforts, we synthesized a group of new nucleoside analogues, which are modified at the sugar moiety that is replaced by a quinazoline entity. Different nucleobase derivatives are used in order to increase the inhibition. Five new nucleoside analogues were evaluated with in vitro assays for targeting polymerase of SARS-CoV-2.

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.

Design, synthesis and in silico studies of new quinazolinone derivatives as antitumor PARP-1 inhibitors

Herein, we report an eco-friendly synthesis of a new series of quinazolinone-based derivatives as potential PARP-1 inhibitors. The 4-quinazolinone scaffold was utilized as a bioisostere to the phthalazinone core of the reference compound Olaparib. Most of the synthesized compounds displayed appreciable inhibitory activity against PARP-1. Compound 12c showed inhibitory activity at IC50 = 30.38 nM comparable to Olaparib, which has IC50 = 27.89 nM. Cell cycle analysis was performed for compounds 12a and 12c, and both exhibited cell growth arrest at G2/M phase in the MCF-7 cell line. In addition, both compounds increased the programmed apoptosis compared to the control. Furthermore, molecular docking of the final compounds into the PARP-1 active site was executed to explore their probable binding modes. Also, a computational QSAR and in silico ADMET study was performed. The results of this study revealed that some of the newly synthesized compounds could serve as a new framework to discover new PARP-1 inhibitors with anti-cancer activity.

Discovery of quinazoline-2,4(1H,3H)-dione derivatives as novel PARP-1/2 inhibitors: design, synthesis and their antitumor activity

Novel quinazoline-2,4(1H,3H)-dione derivatives bearing a 3-amino pyrrolidine motif were identified as potent PARP-1/2 inhibitors with distinct binding features.

Current research on anti-breast cancer synthetic compounds

Breast cancer (BC) is the most common cancer for females and its incidence tends to increase year by year.

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.

Structural Basis for Potency and Promiscuity in Poly(ADP-ribose) Polymerase (PARP) and Tankyrase Inhibitors

Selective inhibitors could help unveil the mechanisms by which inhibition of poly(ADP-ribose) polymerases (PARPs) elicits clinical benefits in cancer therapy. We profiled 10 clinical PARP inhibitors and commonly used research tools for their inhibition of multiple PARP enzymes. We also determined crystal structures of these compounds bound to PARP1 or PARP2. Veliparib and niraparib are selective inhibitors of PARP1 and PARP2; olaparib, rucaparib, and talazoparib are more potent inhibitors of PARP1 but are less selective. PJ34 and UPF1069 are broad PARP inhibitors; PJ34 inserts a flexible moiety into hydrophobic subpockets in various ADP-ribosyltransferases. XAV939 is a promiscuous tankyrase inhibitor and a potent inhibitor of PARP1 in vitro and in cells, whereas IWR1 and AZ-6102 are tankyrase selective. Our biochemical and structural analysis of PARP inhibitor potencies establishes a molecular basis for either selectivity or promiscuity and provides a benchmark for experimental design in assessment of PARP inhibitor effects.

PARP inhibitors as antitumor agents: a patent update (2013-2015)

INTRODUCTION

PARP inhibitors have been extensively explored as antitumor agents and have shown potent efficacy both in vitro and in vivo. They can be used in monotherapy under the synthetic lethality concept or in combination with radiotherapy or chemotherapy, inducing a synergistic effect. Areas covered: This review covers relevant efforts in the development of PARP inhibitors with a particular focus on recently patented PARP inhibitors, combination therapy involving PARP inhibitors, tumor responsiveness to PARP inhibitors as detailed in reports made from 2013 - 2015, and PARP drugs in clinical trials and other novel inhibitors that emerged in 2013 - 2015. Expert opinion: Clinical studies and applications of PARP inhibitors as antitumor agents have gained considerable recognition in the last few years. In addition to FDA-approved olaparib, an increasing number of new inhibitors have been designed and synthesized, some of which are under preclinical or clinical evaluation. Novel inhibitors are still required, especially new scaffold compounds or drugs with improved properties, such as higher selectivity, higher potency and lower toxicity. The development of combination therapies involving PARP inhibitors and the exploration of biomarkers to predict outcomes with PARP inhibitors would expand the applications of these inhibitors, allowing more patients to benefit from this promising class of drugs in the future.

2-(4-Fluorophenyl)-quinazolin-4(3H)-one as a novel tyrosinase inhibitor: Synthesis, inhibitory activity, and mechanism

2-(4-Fluorophenyl)-quinazolin-4(3H)-one (FQ) was synthesized, and its structure was identified with (1)H nuclear magnetic resonance ((1)H NMR), (13)C nuclear magnetic resonance ((13)C NMR), fourier transform infrared spectroscopy (FTIR), and high resolution mass spectrometry (HRMS). From the enzyme analysis, the results showed that it could inhibit the diphenolase activity of tyrosinase (IC50=120±2μM). Furthermore, the results of kinetic studies showed that the compound was a reversible mixed-type inhibitor, and that the inhibition constants were determined to be 703.2 (KI) and 222.1μM (KIS). The results of fluorescence quenching experiment showed that the compound could interact with tyrosinase and the substrates (tyrosine and l-DOPA). Molecular docking analysis revealed that the mass transfer rate was affected by FQ blocking the enzyme catalytic center. In brief, current study identified a novel tyrosinase inhibitor which deserved further study for hyperpigmentation drugs.

An Update on Poly(ADP-ribose)polymerase-1 (PARP-1) Inhibitors: Opportunities and Challenges in Cancer Therapy

Poly(ADP-ribose)polymerase-1 (PARP-1) is a critical DNA repair enzyme in the base excision repair pathway. Inhibitors of this enzyme comprise a new type of anticancer drug that selectively kills cancer cells by targeting homologous recombination repair defects. Since 2010, important advances have been achieved in PARP-1 inhibitors. Specifically, the approval of olaparib in 2014 for the treatment of ovarian cancer with BRCA mutations validated PARP-1 as an anticancer target and established its clinical importance in cancer therapy. Here, we provide an update on PARP-1 inhibitors, focusing on breakthroughs in their clinical applications and investigations into relevant mechanisms of action, biomarkers, and drug resistance. We also provide an update on the design strategies and the structural types of PARP-1 inhibitors. Opportunities and challenges in PARP-1 inhibitors for cancer therapy will be discussed based on the above advances.

Quinazolines and quinazolinones as ubiquitous structural fragments in medicinal chemistry: An update on the development of synthetic methods and pharmacological diversification

Nitrogen-rich heterocycles, particularly quinazolines and quinazolinones, represent a unique class of diversified frameworks displaying a broad spectrum of biological functions. Over the past several years, intensive medicinal chemistry efforts have generated numerous structurally functionalized quinazoline and quinazolinone derivatives. Interest in expanding the biological effects, demonstrated by these motifs, is growing exponentially, as indicated by the large number of publications reporting the easy accessibility of these skeletons in addition to the diverse nature of synthetic as well as biological applications. Therefore, the main focus of the present review is to provide an ample but condensed overview on various synthetic approaches providing access to quinazoline and quinazolinone compounds with multifaceted biological activities. Furthermore, mechanistic insights, synthetic utilization, structure-activity relationships and molecular modeling inputs for the potent derivatives have also been discussed.

Poly (ADP-ribose) polymerases inhibitor, Zj6413, as a potential therapeutic agent against breast cancer

Poly (ADP-ribose) polymerases (PARPs) facilitate repairing of cancer cell DNA damage as a mean to promote cancer proliferation and metastasis. Inhibitors of PARPs which interfering DNA repair, in context of defects in other DNA repair mechanisms, can thus be potentially exploited to inhibit or even kill cancer cells. However, nondiscriminatory inhibition of PARPs, such as PARP2, may lead to undesired consequences. Here, we demonstrated the design and development of the Zj6413 as a potent and selective PARP1 catalytic inhibitor. It trapped PARP1/2 at damaged sites of DNA. As expected, the Zj6413 showed notable anti-tumor activity against breast cancer gene (BRCA) deficient triple negative breast cancers (TNBCs). Zj6413 treated breast cancers (BCs) showed an elevated level of DNA damage evidenced by the accumulation of γ-H2AX foci and DNA damaged related proteins. Zj6413 also induced G2/M arrest and cell death in the MX-1, MDA-MB-453 BC cells, exerted chemo-sensitizing effect on BRCA proficient cancer cells and potentiated Temozolomide (TMZ)'s cytotoxicity in MX-1 xenograft tumors mice. In conclusion, our study provided evidence that a new PARP inhibitor strongly inhibited the catalytic activity of PARPs, trapped them on nicked DNA and damaged the cancer cells, eventually inhibiting the growth of breast tumor cells in vitro and in vivo.

Predicting Molecular Targets for Small-Molecule Drugs with a Ligand-Based Interaction Fingerprint Approach

The computational prediction of molecular targets for small-molecule drugs remains a great challenge. Herein we describe a ligand-based interaction fingerprint (LIFt) approach for target prediction. Together with physics-based docking and sampling methods, we assessed the performance systematically by modeling the polypharmacology of 12 kinase inhibitors in three stages. First, we examined the capacity of this approach to differentiate true targets from false targets with the promiscuous binder staurosporine, based on native complex structures. Second, we performed large-scale profiling of kinase selectivity on the clinical drug sunitinib by means of computational simulation. Third, we extended the study beyond kinases by modeling the cross-inhibition of bromodomain-containing protein 4 (BRD4) for 10 well-established kinase inhibitors. On this basis, we made prospective predictions by exploring new kinase targets for the anticancer drug candidate TN-16, originally known as a colchicine site binder and microtubule disruptor. As a result, p38α was highlighted from a panel of 187 different kinases. Encouragingly, our prediction was validated by an in vitro kinase assay, which showed TN-16 as a low-micromolar p38α inhibitor. Collectively, our results suggest the promise of the LIFt approach in predicting potential targets for small-molecule drugs.