Synthesis, biological evaluation and molecular modeling study of some new methoxylated 2-benzylthio-quinazoline-4(3H)-ones as nonclassical antifolates

Synthesis and Biological Evaluation of Some New 3-Aryl-2-thioxo-2,3-dihydroquinazolin-4(1H)-ones and 3-Aryl-2-(benzylthio)quinazolin-4(3H)-ones as Antioxidants; COX-2, LDHA, α-Glucosidase and α-Amylase Inhibitors; and Anti-Colon Carcinoma and Apoptosis-Inducing Agents

Oxidative stress, COX-2, LDHA and hyperglycemia are interlinked contributing pathways in the etiology, progression and metastasis of colon cancer. Additionally, dysregulated apoptosis in cells with genetic alternations leads to their progression in malignant transformation. Therefore, quinazolinones 3a-3h and 5a-5h were synthesized and evaluated as antioxidants, enzymes inhibitors and cytotoxic agents against LoVo and HCT-116 cells. Moreover, the most active cytotoxic derivatives were evaluated as apoptosis inducers. The results indicated that 3a, 3g and 5a were efficiently scavenged DPPH radicals with lowered IC50 values (mM) ranging from 0.165 ± 0.0057 to 0.191 ± 0.0099, as compared to 0.245 ± 0.0257 by BHT. Derivatives 3h, 5a and 5h were recognized as more potent dual inhibitors than quercetin against α-amylase and α-glucosidase, in addition to 3a, 3c, 3f and 5b-5f against α-amylase. Although none of the compounds demonstrated a higher efficiency than the reference inhibitors against COX-2 and LDHA, 3a and 3g were identified as the most active derivatives. Molecular docking studies were used to elucidate the binding affinities and binding interactions between the inhibitors and their target proteins. Compounds 3a and 3f showed cytotoxic activities, with IC50 values (µM) of 294.32 ± 8.41 and 383.5 ± 8.99 (LoVo), as well as 298.05 ± 13.26 and 323.59 ± 3.00 (HCT-116). The cytotoxicity mechanism of 3a and 3f could be attributed to the modulation of apoptosis regulators (Bax and Bcl-2), the activation of intrinsic and extrinsic apoptosis pathways via the upregulation of initiator caspases-8 and -9 as well as executioner caspase-3, and the arrest of LoVo and HCT-116 cell cycles in the G2/M and G1 phases, respectively. Lastly, the physicochemical, medicinal chemistry and ADMET properties of all compounds were predicted.

New quinazolinone-based derivatives as DHFR/EGFR-TK inhibitors: Synthesis, molecular modeling simulations, and anticancer activity

New 2-mercapto-quinazolin-4-one analogs were synthesized and tested for their in vitro anticancer activity, dihydrofolate reductase (DHFR) inhibition, and epidermal growth factor tyrosine kinase (EGFR-TK) inhibition activities. Compound 24, which is characterized by a 2-benzyl-thio function, showed broad-spectrum anticancer activity with high safety profile and selectivity index. The concentrations of 24 causing 50% growth inhibition (GI₅₀ ) and total cell growth inhibition (TGI) and its lethal concentration 50 (LC₅₀ ) were 15.1, 52.5, and 91.2 µM, respectively, using 5-fluorouracil as a positive control. Also, it showed EGFR-TK inhibitory activity with IC₅₀  = 13.40 nM compared to gefitinib (IC₅₀  = 18.14 nM) and DHFR inhibitory potency with 0.30 μM compared to methotrexate (MTX; IC₅₀  = 0.08 μM). In addition, compound 24 caused cell cycle arrest and apoptosis on COLO-205 colon cancer cells. Compounds 37, 21, and 54 showed remarkable DHFR inhibitory activity with IC₅₀ values of 0.03, 0.08, and 0.08 μM, respectively. The inhibitory properties of these compounds are due to an electron-withdrawing group on the quinazolinone ring, except for compound 54. In a molecular modeling study, compound 24 showed the same binding mode as gefitinib as it interacted with the amino acid Lys745 via π-π interaction. Compound 37 showed a similar binding mode as MTX through the binding interaction with Lys68, Asn64 via hydrogen bond acceptor, and Phe31 via arene-arene interaction. The obtained model and substitution pattern could be used for further development.

Dihydrofolate reductase inhibitors: patent landscape and phases of clinical development (2001-2021)

INTRODUCTION

Dihydrofolate reductase (DHFR) plays an important role in the biosynthesis of amino acid and folic acid. It participates by reducing dihydrofolate to tetrahydrofolate, in the presence of nicotinamide dinucleotide phosphate cofactor, and has been verified by various clinical studies to use DHFR as a target for the treatment of cancer and various bacterial infections.

AREA COVERED

In this review, we have disclosed patents of synthetics and natural DHFR inhibitors with diaminopyrimidine and quinazoline nucleus from 2001. Additionally, this review highlights the clinical progression of numerous DHFR inhibitors received from the last five years.

EXPERT OPINION

From 2001 to 2021, numerous active chemical scaffolds have been introduced and are exposed as lead candidates that have entered clinical trials as potent DHFR inhibitors. Moreover, researchers have paid considerable attention to the development of a new class of DHFR inhibitors with higher selectivity and potency. This development includes synthesis of synthetic as well as natural compounds that are potent DHFR inhibitors. On the basis of literature review, we can anticipate that there are a huge number of novel active molecules available for the future that could possess superior abilities to target this enzyme with a profound pharmacological profile.

Synthesis, antitumor activity, 3D-QSAR and molecular docking studies of new iodinated 4-(3H)-quinazolinones 3N-substituted

A novel series of 6-iodo-2-methylquinazolin-4-(3H)-one derivatives, 3a–n, were synthesized and evaluated for their in vitro cytotoxic activity. Compounds 3a, 3b, 3d, 3e, and 3h showed remarkable cytotoxic activity on specific human cancer cell lines when compared to the anti-cancer drug, paclitaxel. Compound 3a was found to be particularly effective on promyelocytic leukaemia HL60 and non-Hodgkin lymphoma U937, with IC₅₀ values of 21 and 30 μM, respectively. Compound 3d showed significant activity against cervical cancer HeLa (IC₅₀ = 10 μM). The compounds 3e and 3h were strongly active against glioblastoma multiform tumour T98G, with IC₅₀ values of 12 and 22 μM, respectively. These five compounds showed an interesting cytotoxic activity on four human cancer cell types of high incidence. The molecular docking results reveal a good correlation between experimental activity and calculated binding affinity on dihydrofolate reductase (DHFR). Docking studies proved 3d as the most potent compound. In addition, the three-dimensional quantitative structure–activity relationship (3D-QSAR) analysis exhibited activities that may indicate the existence of electron-withdrawing and lipophilic groups at the para-position of the phenyl ring and hydrophobic interactions of the quinazolinic ring in the DHFR active site.

New iodinated 4-(3H)-quinazolinones 3N-substituted with antitumor activity and 3D-QSAR and molecular docking studies as dihydrofolate reductase (DHFR) inhibitors.

Thioethers: An Overview

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Spreading rapidly in recent years, cancer has become one of the causes of the highest mor-tality rates after cardiovascular diseases. The reason for cancer development is still not clearly under-stood despite enormous research activities in this area. Scientists are now working on the biology of cancer, especially on the root cause of cancer development. The aim is to treat the cancer disease and thus cure the patients. The continuing efforts for the development of novel molecules as potential anti-cancer agents are essential for this purpose. The main aim of this review was to present a survey on the medicinal chemistry of thioethers and provide practical data on their cytotoxicities against various cancer cell lines. The research articles published between 2001-2020 were consulted to pre-pare this review article; however, patent literature has not been included. The thioether-containing heterocyclic compounds may emerge as a new class of potent and effective anti-cancer agents in the future.

Novel 2,4-disubstituted quinazoline analogs as antibacterial agents with improved cytotoxicity profile: Modification of the benzenoid part

Bacterial resistance to currently used antibiotics demands the development of novel antibacterial agents with good safety margins and sufficient efficacy against multi-drug resistant isolates. We have previously described the synthesis of N-butyl-2-(butylthio)quinazolin-4-amine (I) as an optimized hit with broad-spectrum antibacterial activity and low cytotoxicity. In addition, we have identified a potential growing vector for this series of compounds. Herein, we describe further hit optimization which includes systematic diversifications of both the benzenoid part and the substituents at position 6 and 7 of compound I. Growing of the molecule beside the core modifications yielded several compounds with remarkable anti(myco)bacterial activity against a panel of pathogenic bacteria, including drug-resistant strains. Compound 12 showed a 2-4 fold improvement in activity than I against S. aureus Newman, S. pneumoniae DSM-20566 and E. faecalis DSM-20478. The compounds also showed a good safety profile towards human HepG2 cells.

Anticancer Evaluation of Novel Quinazolinone Acetamides: Synthesis and Characterization

BACKGROUND

According to the global cancer report of 2019, the burden of cancer will exceed more than 18 million becoming one of the major causes of global mortality rate. There is a pressing need to establish novel drug candidates for cancer treatment, though many anticancer agents are available in the market owing to their adverse effects. 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.

OBJECTIVE

The objective of this study is to evaluate the anti-cancer potential of the novel class of quinazoline tethered acetamide derivatives against six different cancer cell lines.

METHOD

A novel series of various substituted quinazolinone acetamides were synthesized through a feasible scheme. The synthetic scheme involves the conversion of benzoxazinone (from anthranilic acid and benzoyl chloride) intermediate to 3-amino quinazoline-4-one which is further converted to the final amide by tethering with the propionyl chloride employing Schotten-Baumann Reaction conditions. All the synthesized derivatives characterized by IR, 1HNMR and MASS spectral methods and anti-cancer activity evaluated by employing MTT assay for six cancer cell lines and one normal human cell line.

RESULTS

All the synthesized compounds were screened for anti-cancer activity against six cancer cell lines, including A 549 (lung), DU 145 (prostate), HT 29 (colon), MCF-7 (breast), SiHA (cervical), B16F10 (mouse skin melanoma) and one normal human fibroblast cell lines. All the compounds displayed a decent cytotoxicity profile when compared with the standard drug, doxorubicin. Among the synthesized compounds (5a to 5n) tested, two compounds, 5f and 5g have demonstrated excellent cytotoxicity against SiHA and MCF-7 cancer cell lines.

CONCLUSION

Comparatively, most of the compounds displayed decent cytotoxicity potential relative to the standard drug, doxorubicin. Further investigations are needed to establish the detailed mechanism of action of the developed novel quinazolinone acetamides.

Recent Design and Structure-Activity Relationship Studies on the Modifications of DHFR Inhibitors as Anticancer Agents

BACKGROUND

Dihydrofolate reductase (DHFR) has been known for decades as a molecular target for antibacterial, antifungal and anti-malarial treatments. This enzyme is becoming increasingly important in the design of new anticancer drugs, which is confirmed by numerous studies including modelling, synthesis and in vitro biological research. This review aims to present and discuss some remarkable recent advances in the research of new DHFR inhibitors with potential anticancer activity.

METHODS

The scientific literature of the last decade on the different types of DHFR inhibitors has been searched. The studies on design, synthesis and investigation structure-activity relationships were summarized and divided into several subsections depending on the leading molecule and its structural modification. Various methods of synthesis, potential anticancer activity and possible practical applications as DHFR inhibitors of new chemical compounds were described and discussed.

RESULTS

This review presents the current state of knowledge on the modification of known DHFR inhibitors and the structures and searches for about eighty new molecules, designed as potential anticancer drugs. In addition, DHFR inhibitors acting on thymidylate synthase (TS), carbon anhydrase (CA) and even DNA-binding are presented in this paper.

CONCLUSION

Thorough physicochemical characterization and biological investigations highlight the structure-activity relationship of DHFR inhibitors. This will enable even better design and synthesis of active compounds, which would have the expected mechanism of action and the desired activity.

A Review of Small-Molecule Inhibitors of One-Carbon Enzymes: SHMT2 and MTHFD2 in the Spotlight

Metabolic reprogramming is a key hallmark of cancer and shifts cellular metabolism to meet the demands of biomass production necessary for abnormal cell reproduction. One-carbon metabolism (1CM) contributes to many biosynthetic pathways that fuel growth and is comprised of a complex network of enzymes. Methotrexate and 5-fluorouracil were pioneering drugs in this field and are still widely used today as anticancer agents as well as for other diseases such as arthritis. Besides dihydrofolate reductase and thymidylate synthase, two other enzymes of the folate cycle arm of 1CM have not been targeted clinically: serine hydroxymethyltransferase (SHMT) and methylenetetrahydrofolate dehydrogenase (MTHFD). An increasing body of literature suggests that the mitochondrial isoforms of these enzymes (SHMT2 and MTHFD2) are clinically relevant in the context of cancer. In this review, we focused on the 1CM pathway as a target for cancer therapy and, in particular, SHMT2 and MTHFD2. The function, regulation, and clinical relevance of SHMT2 and MTHFD2 are all discussed. We expand on previous clinical studies and evaluate the prognostic significance of these critical enzymes by performing a pan-cancer analysis of patient data from the The Cancer Genome Atlas and a transcriptional coexpression network enrichment analysis. We also provide an overview of preclinical and clinical inhibitors targeting the folate pathway, the methionine cycle, and folate-dependent purine biosynthesis enzymes.

Microwave Assisted Synthesis of 4-Phenylquinazolin-2(1H)-one Derivatives that Inhibit Vasopressor Tonus in Rat Thoracic Aorta

Quinazolinones have pharmacological effects on vascular reactivity through different mechanisms. We synthesized 4-phenylquinazolin-2(1H)-one derivatives under microwave irradiation and tested them on the rat thoracic aorta. The prepared compounds 2a–2f were obtained in about 1 h with suitable yields (31–92%). All derivatives produced vasorelaxant effects with IC₅₀ values ranging from 3.41 ± 0.65 µM to 39.72 ± 6.77 µM. Compounds 2c, 2e and 2f demonstrated the highest potency in endothelium-intact aorta rings (IC₅₀ 4.31 ± 0.90 µM, 4.94 ± 1.21 µM and 3.41 ± 0.65 µM respectively), and they achieved around 90% relaxation (30 μM). In aorta rings without an endothelium, the effect of compound 2f was abolished. Using the MTT assay to test for cell viability, only compound 2b induced cytotoxicity at the maximum concentration employed (30 µM). The results show that vasorelaxation by 4-phenylquinazolin-2(1H)-one derivatives might depend on the activation of a signalling pathway triggered by endothelium-derived factors.

Synthesis, molecular modeling and anti-cancer evaluation of a series of quinazoline derivatives

Quinazolines were surveyed as biologically relevant moieties against different cancer cell lines, so in the present study, we analyzed novel derivatives as target-oriented chemotherapeutic anti-cancer drugs. A series of 3-substituted 2-thioxo-2,3-dihydro-1H-quinazolin-4-ones 4a-e were synthesized via the reaction of 2-aminobenzoic acid (1) with isothiocyanate derivatives 2a-e. S-alkylation and S-glycosylation were carried via the reaction of 4a-e with alkyl halides and α-glycopyranosyl bromides 7a,b under anhydrous alkaline and glycoside conditions, respectively. The S-alkylated and S-glycosylated structures, and not that of the N-alkylated and N-glycosylated isomers, have been selected for the products. Conformational analysis has been studied by homo- and heteronuclear two-dimensional NMR methods (DQF-COSY, HMQC, and HMBC). The S site of alkylation and glycosylation were determined from the ¹H, ¹³C heteronuclear multiple-quantum coherence (HMQC) experiments. All derivatives were subjected to molecular docking calculations, which selected some derivatives (5n, 8c, 8g, 9c, and 9a) as promising ones based on their excellent binding affinities towards the EGFR tyrosine kinase molecular target. The in vitro cytotoxic activity against MCF-7 and HepG2 cell lines showed effective anti-proliferative activity of the analyzed derivatives with lower IC₅₀ values especially 9a with IC₅₀ = 2.09 and 2.08 μM against MCF-7 and HepG2, respectively, and their treatments were safe against the normal cell line Gingival mesenchymal stem cells (GMSC). Moreover, RT-PCR reaction investigated the apoptotic pathway for the compound 9a, which activated the P53 genes and its related genes. So, further work is recommended for developing it as a chemotherapeutic drug.

DHFR Inhibitors: Reading the Past for Discovering Novel Anticancer Agents

Dihydrofolate reductase inhibitors are an important class of drugs, as evidenced by their use as antibacterial, antimalarial, antifungal, and anticancer agents. Progress in understanding the biochemical basis of mechanisms responsible for enzyme selectivity and antiproliferative effects has renewed the interest in antifolates for cancer chemotherapy and prompted the medicinal chemistry community to develop novel and selective human DHFR inhibitors, thus leading to a new generation of DHFR inhibitors. This work summarizes the mechanism of action, chemical, and anticancer profile of the DHFR inhibitors discovered in the last six years. New strategies in DHFR drug discovery are also provided, in order to thoroughly delineate the current landscape for medicinal chemists interested in furthering this study in the anticancer field.

Design, Synthesis, and Biological Evaluation of Triazolyl- and Triazinyl-Quinazolinediones as Potential Antitumor Agents

Novel 6(3-1H-1,2,4-triazol-1-yl)-3-phenylquinazoline-2,4(1H,3H)-diones (7a–e) were synthesized from different enaminones (6a–e) with 6-hydrazinyl-3-phenylquinazoline-2,4(1H,3H)-dione. 2,6(4-2-Substituted-1,3,5-triazin-1(2H)-yl)-3-phenylquinazoline-2,4(1H,3H)-diones (8a–k) were synthesized from the reaction of 1-(2,4-dioxo-3-phenyl-1,2,3,4-tetrahydroquinazolin-6-yl)thiourea, urea, or guanidine (3a–c) with enaminones (6a–e), and a series from 3-substituted-2-imino-1,3,5-triazin-1(2H)-yl-sulfonyl-phenyl-1-methylquinazoline-2,4(1H,3H)-dione (12a–j) were obtained from the reaction of N-(diaminomethylene)-4-(1-methyl-2,4-dioxo-1,2-dihydroquinazolin-3(4H)-yl)benzenesulfonamide (11) with the enaminone (6a–j). The antitumor activity of the synthesized compounds was evaluated against two human cell lines: human colon carcinoma HCT116 and human hepatocellular carcinoma HEP-G2. Some of the tested compounds showed significant potency compared to the reference drug staurosporin.

Synthesis and anticancer activity of new quinazoline derivatives

In this study, a new series of quinazoline derivatives (3–26) was synthesized and characterized via physicochemical and spectral means. Treatment of 2-amino-5-methylbenzoic acid with butyl isothiocyanate resulted in the new 2-thioxoquinazolin-4-one (3). Alkylation and hydrazinolysis of the inherent thioxo group in (1–3) afforded the corresponding thioethers (4–23) and hydrazine derivatives (24 and 25), then 24 was further transformed into tricyclic derivative 26 via cyclocondensation reaction. Compounds 1 and 2, which were previously synthesized, were found to exhibit anticancer activity. The cytotoxicity of all compounds was evaluated in vitro against the HeLa and MDA-MB231 cancer cell lines, including 1 and 2 for comparison, using MTT assay. The treatment of the cells was performed with the synthesized compounds and gefitinib at 0, 1, 5, 10, 25, and 50 μM and incubated for 24 h in 50% DMSO. The IC₅₀ values of the target compounds were reported in μM, using gefitinib as a standard. Our results indicated that all compounds exhibited significant in vitro cytotoxicity against both cell lines. While compounds 1–3 showed good activity, compounds 21–23 were found to be more potent than gefitinib. Thus, compounds 21–23 may be potential anticancer agents, with IC₅₀ values ranging from 1.85 to 2.81 μM in relation to gefitinib (IC₅₀ = 4.3 and 28.3 μM against HeLa and MDA-MB231 cells, respectively).