Surrogating and redirection of pyrazolo[1,5-a]pyrimidin-7(4H)-one core,a novel class of potent and selective DPP-4 inhibitors

The initial focus on characterizing novel pyrazolo[1,5-a]pyrimidin-7(4H)-one derivatives as DPP-4 inhibitors, led to a potent and selective inhibitor compound b2. This ligand exhibits potent in vitro DPP-4 inhibitory activity (IC₅₀: 80?nM), while maintaining other key cellular parameters such as high selectivity, low cytotoxicity and good cell viability. Subsequent optimization of b2 based on docking analysis and structure-based drug design knowledge resulted in d1. Compound d1 has nearly 2-fold increase of inhibitory activity (IC₅₀: 49?nM) and over 1000-fold selectivity against DPP-8 and DPP-9. Further in vivo IPGTT assays showed that compound b2 effectively reduce glucose excursion by 34% at the dose of 10?mg/kg in diabetic mice. Herein we report the optimization and design of a potent and highly selective series of pyrazolo[1,5-a]pyrimidin-7(4H)-one DPP-4 inhibitors.     

Anticancer evaluation and molecular modeling of multi-targeted kinase inhibitors based pyrido[2,3-d]pyrimidine scaffold

An efficient synthesis of substituted pyrido[2,3-d]pyrimidines was carried out and evaluated for in vitro anticancer activity against five cancer cell lines, namely hepatic cancer (HepG-2), prostate cancer (PC-3), colon cancer (HCT-116), breast cancer (MCF-7), and lung cancer (A-549) cell lines. Regarding HepG-2, PC-3, HCT-116 cancer cell lines, 7-(4-chlorophenyl)-2-(3-methyl-5-oxo-2,3-dihydro-1H-pyrazol-1-yl)-5-(p-tolyl)- pyrido[2,3-d]pyrimidin-4(3H)-one (5a) exhibited strong, more potent anticancer (IC₅₀: 0.3, 6.6 and 7?µM) relative to the standard doxorubicin (IC₅₀: 0.6, 6.8 and 12.8?µM), respectively. Kinase inhibitory assessment of 5a showed promising inhibitory activity against three kinases namely PDGFR β, EGFR, and CDK4/cyclin D1 at two concentrations 50 and 100?µM in single measurements. Further, a molecular docking study for compound 5a was performed to verify the binding mode towards the EGFR and CDK4/cyclin D1 kinases.     

Synthesis of indole-tethered [1,3,4]thiadiazolo and [1,3,4]oxadiazolo[3,2-a]pyrimidin-5-one hybrids as anti-pancreatic cancer agents

New indole-tethered [1,3,4]thiadiazolo[3,2-a]pyrimidin-5-one (8a-j) and [1,3,4]oxadiazolo[3,2-a]pyrimidin-5-one hybrids (9a-e) were synthesized using [4+2] cycloaddition reactions of functionalized 1,3-diazabuta-1,3-dienes with indole-ketenes. All molecular hybrids were structurally characterized by spectroscopic techniques (IR, NMR, and HRMS) and screened for their anti-pancreatic cancer activity in vitro. The [1,3,4]oxadiazolo[3,2-a]pyrimidin-5-one hybrids (9a-e) showed stronger anti-pancreatic cancer activity than the [1,3,4]thiadiazolo[3,2-a]pyrimidin-5-one hybrids (8a-j) against the PANC-1 cell line. Compound 9d bearing an ortho-chlorophenyl moiety emerged as the most potent anti-pancreatic cancer agent with an IC₅₀ value of 7.7 ± 0.4 µM, much superior to the standard drug Gemcitabine (IC₅₀ > 500 µM). The discovery of these [1,3,4]thiadiazolo and [1,3,4]oxadiazolo[3,2-a]pyrimidin-5-one hybrids elicits their potentials as pursuable candidates for pancreatic cancer chemotherapy.     

Design,synthesis, and anti-cancer evaluation of new pyrido[2,3-d]pyrimidin-4(3H)-one derivatives as potential EGFRWT and EGFRT790M inhibitors and apoptosis inducers

A new series of pyrido[2,3-d]pyrimidin-4(3H)-one derivatives having the essential pharmacophoric features of EGFR inhibitors has been designed and synthesised. Cell viability screening was performed for these compounds against A-549, PC-3, HCT-116, and MCF-7 cell lines at a dose of 100 μM. The highest active derivatives (8a, 8 b, 8d, 9a, and 12b) were selected for IC₅₀ screening. Compounds 8a, 8 b, and 9a showed the highest cytotoxic activities and were further investigated for wild EGFR^WT and mutant EGFR^T790M inhibitory activities. Compound 8a showed the highest inhibitory activities against EGFR^WT and EGFR^T790M with IC₅₀ values of 0.099 and 0.123 µM, respectively. In addition, it arrested the cell cycle at pre-G1 phase and induced a significant apoptotic effect in PC-3 cells. Furthermore, compound 8a induced a 5.3-fold increase in the level of caspase-3 in PC-3 cells. Finally, docking studies were carried out to examine the binding mode of the synthesised compounds against both EGFR^WT and EGFR^T790M.     

Synthesis of new pyridothienopyrimidinone and pyridothienotriazolopyrimidine derivatives as pim-1 inhibitors

Three series of 2-arylpyridothieno[3,2-d]pyrimidin-4-ones 3a–j, pyridothienotriazolopyrimidines 6–8 and 4-imino-pyridothieno[3,2-d]pyrimidines 9a,b were prepared to improve the pim-1 inhibitory activity of the previously reported 2-arylpyridothieno[3,2-d]pyrimidin-4-ones. All the test compounds showed highly potent pim-1 inhibition with IC₅₀ in the range of 0.06–1.76?µM. No significant difference was detected between the pim-1 inhibitory activity of the 4-pyrimidinone and the 4-imino (=NH) or the cyclised triazolopyrimidine derivatives. The most active compounds were tested for their cytotoxic activity on MCF7 and HCT116 and showed potent activity on both the cell lines.     

Synthesis and anticancer evaluation of 3-substituted quinolin-4-ones and 2,3-dihydroquinolin-4-ones

A series of 3-aryl-5,7-dimethoxyquinolin-4-ones 8 and 3-aryl-5,7-dimethoxy-2,3-dihydroquinolin-4-ones 13 were synthesized in good yields. Demethylation under a range of conditions afforded the corresponding 5-hydroxy and 5,7-dihydroxy derivatives. Biological evaluation against a range of cancer cells lines showed that the quinolin-4-one scaffold was more cytotoxic than the reduced 2,3-dihydroquinolin-4-one scaffold. The most active monohydroxy compound 15f demonstrated 85.9–99% reduction in cell viability against the cell lines tested.     

Synthesis of new bioactive venlafaxine analogs: novel thiazolidin-4-ones as antimicrobials

A one-pot, three-component, microwave irradiated and conventional solution-phase synthesis of bioactive venlafaxine analogs such as 2,3-disubstituted-1,3-thiazolidin-4-ones 3a-j under mild conditions and their characterization are reported. The novel thiazolidin-4-ones, 3-(2-(1-hydroxycyclohexyl)-2-(4-methoxyphenyl)ethyl)-2-phenyl-thiazolidin-4-one 3a, 2-(2,6-difluorophenyl)-3-(2-(1-hydroxycyclohexyl)-2-(4-methoxyphenyl)ethyl)thiazolidin-4-one 3c, and 2-(furan-2-yl)-3-(2-(1-hydroxycyclohexyl)-2-(4-methoxyphenyl)ethyl)thiazolidin-4-one 3i, were characterized by the single crystal X-ray diffraction method. The cyclohexane ring of all the three molecules is in chair conformation. All the synthesized compounds were screened for their efficacy as antimicrobials in vitro by the disk diffusion and microdilution method against pathogenic strains such as Bacillus subtilis, Escherichia coli, Pseudomonas fluorescens, Xanthomonas campestris pvs, Xanthomonas oryzae, Aspergillus niger, Aspergillus flavus, Fusarium oxysporum, Trichoderma species, and Fusarium monaliforme species. Among these compounds 3c, 3j, 3g, 3d, and 3e showed potent antimicrobial activity, when compared to standard drugs.     

Rational design and synthesis of novel thiazolidin-4-ones as non-nucleoside HIV-1 reverse transcriptase inhibitors

A series of novel thiazolidin-4-one analogues, characterized by different substitution patterns at positions C-2 and N-3 of the thiazolidin-4-one scaffold for anti-HIV-1 activity has been investigated. Most of the compounds showed anti-HIV-1 activity at micromolar concentrations when tested in TZM-bl cells in vitro. Among the thirty-three compounds tested, compound 16 was the most potent inhibitor of HIV-1 replication against HIV-1_IIIB, HIV-1_ADA5, HIV-1_UG070 and HIV-1_VB59 (EC₅₀ = 0.02, 0.08, 0.08 and 0.08 μM, respectively) with selectivity index (SI = 6940, 1735, 1692 and 1692) against tested viral strains, respectively. The results of the present study suggested that the substitution of the nitro group at 6′ position of the C-2 phenyl ring and 4,6-dimethylpyridin-2-yl at the N-3 position of thiazolidin-4-one had a major impact on the anti-HIV-1 activity and was found to lower cytotoxicity. The substitution of the heteroaryl ring with bromo group and bicyclic heteroaryl ring at N-3 thiazolidin-4-one was found to lower anti-HIV-1 activity and increase cytotoxicity. The undertaken docking studies thus facilitated the identification of crucial interactions between the HIV-1 RT enzyme and thiazolidin-4-one inhibitors, which can be used to design new potential inhibitors.     

Synthesis,characterization, and anticancer evaluation of novel 4-hydrazinothiazole analogs

Single-step synthesis of novel 4-hydrazinothiazole derivatives 6a–e was achieved under mild conditions using the sequential four-components method involving isothiocyanate, aminoguanidine, carbonyl adduct, and α-haloketone derivatives. Deprotection of these hydrazinothiazoles was influenced by acylation, providing a novel group of diacylated molecular structures with a broader scope for the design of thiazolyl-containing drugs 7a and 7b . FTIR, ¹H/¹³C NMR, LC–MS spectroscopy, and CHN elemental analyses were used to study the compound chemical structures. Using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on human periodontal ligament fibroblast (HPDLF) cells, the 4-hydrazinothiazole derivatives were screened for cytotoxicity in an in vitro cytotoxicity investigation. The 4-hydrazinothiazole compound 6b bearing an isopropylidene-hydrazino group demonstrated strongly potent cytotoxicity against CAKI1 (IC₅₀ = 1.65 ± 0.24 μM) and A498 (IC₅₀ of 0.85 ± 0.24 μM). Furthermore, the chloroacetyl-containing thiazole compound 7a displayed efficient inhibition of growth against the test cell lines CAKI1 and A498 at low micromolar concentrations, IC₅₀ 0.78 and 0.74 μM, respectively.     

Quinazolin-4(3H)-one based potential multiple tyrosine kinase inhibitors with excellent cytotoxicity

A series of quinazolin-4(3H)-one derivatives were synthesised and evaluated for their cytotoxicity against human Caucasian breast adenocarcinoma (MCF-7) and human ovarian carcinoma (A2780) cell lines. Cytotoxicity of the most tested compounds was 2- to 30-fold more than the positive control lapatinib (IC₅₀ of 2j = 3.79 ± 0.96; 3j = 0.20 ± 0.02; and lapatinib = 5.9 ± 0.74) against MCF7 cell lines except two compounds (IC₅₀ of 2 b = 15.72 ± 0.07 and 2e = 14.88 ± 0.99). On the other hand, cytotoxicity was 4 − 87 folds (IC₅₀ of 3a = 3.00 ± 1.20; 3 g = 0.14 ± 0.03) more the positive control lapatinib (IC₅₀ = 12.11 ± 1.03) against A2780 cell lines except compound 2e (IC₅₀ = 16.43 ± 1.80). Among the synthesised quinazolin-4(3H)-one derivatives, potent cytotoxic 2f-j and 3f-j were investigated for molecular mechanism of action. Inhibitory activities of the compounds were tested against multiple tyrosine protein kinases (CDK2, HER2, EGFR and VEGFR2) enzymes. As expected, all the quinazolin-4(3H)-one derivatives were showed comparable inhibitory activity against those kinases tested, especially, compound 2i and 3i showed potent inhibitory activity against CDK2, HER2, EGFR tyrosine kinases. Therefore, molecular docking analysis for quinazolin-4(3H)-one derivatives 2i and 3i were performed, and it was revealed that compounds 2i and 3i act as ATP non-competitive type-II inhibitor against CDK2 kinase enzymes and ATP competitive type-I inhibitor against EGFR kinase enzymes. However, in case of HER2, compounds 2i act as ATP non-competitive type-II inhibitor and 3i act as ATP competitive type-I inhibitor. Docking results of known inhibitors were compared with synthesised compounds and found synthesised 2i and 3i are superior than the known inhibitors in case of interactions. In addition, in silico drug likeness properties of quinazolin-4(3H)-one derivatives showed better predicted ADME values than lapatinib.     

2-Heteroarylimino-5-benzylidene-4-thiazolidinones analogues of 2-thiazolylimino-5-benzylidene-4-thiazolidinones with antimicrobial activity: synthesis and structure-activity relationship

2-Heteroarylimino-5-benzylidene-4-thiazolidinones, unsubstituted or carrying hydroxy, methoxy, nitro and chloro groups on the benzene ring, were synthesised and assayed in vitro for their antimicrobial activity against gram positive and gram negative bacteria, yeasts and mould. The antimicrobial activity of the 2-benzo[d]thiazolyl- and of the 2-benzo[d]isothiazolyl-imino-5-benzylidene-4-thiazolidinones is, on the whole, lower in comparison with the high activity detected for the derivatives of the 2-thiazolylimino-5-benzylidene-4-thiazolidinone class. Nevertheless most of the benzo[d]thiazole analogues display good inhibition of the growth of gram positive bacilli and staphylococci, including methicillin-resistant Staphylococcus strains. Among the 2-benzo[d]isothiazole analogues a few derivatives show a strong and selective activity against bacilli. Moreover, it is worth noting that the replacement of the thiazole nucleus for the benzo[d]thiazole bicyclic system in the parent 2-(benzo[d]thiazol-2-ylimino)thiazolidin-4-one leads to significant antifungal properties against both yeasts and moulds, properties not shown by the analogous 2-thiazolyl- and 2-benzo[d]isothiazolyl-imino)thiazolidin-4-ones. The structure-activity relationship of 33 analogues possessing the 2-heteroarylimino-4-thiazolidinone structure is analysed through QSAR models.     

Discovery of pyrrolo[2,3-d]pyrimidin-4-ones as corticotropin-releasing factor 1 receptor antagonists with a carbonyl-based hydrogen bonding acceptor

A new class of pyrrolo[2,3-d]pyrimidin-4-one corticotropin-releasing factor 1 (CRF₁) receptor antagonists has been designed and synthesized. In general, reported CRF₁ receptor antagonists possess a sp²-nitrogen atom as hydrogen bonding acceptor (HBA) on their core scaffolds. We proposed to use a carbonyl group of pyrrolo[2,3-d]pyrimidin-4-one derivatives as a replacement for the sp²-nitrogen atom as HBA in classical CRF₁ receptor antagonists. As a result, several pyrrolo[2,3-d]pyrimidin-4-one derivatives showed CRF₁ receptor binding affinity with IC₅₀ values in the submicromolar range. Ex vivo ¹²⁵I-sauvagine binding studies showed that 2-(dipropylamino)-3,7-dimethyl-5-(2,4,6-trimethylphenyl)-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-one (16b) (30 mg/kg, po) was able to penetrate into the brain and inhibit radioligand binding to CRF₁ receptors (frontal cortex, olfactory bulb, and pituitary) in mice. We identified pyrrolo[2,3-d]pyrimidin-4-one derivatives as the first CRF₁ antagonists with a carbonyl-based HBA.     

Synthesis,anticancer, structural,and computational docking studies of 3-benzylchroman-4-one derivatives

A series of 3-Benzylchroman-4-ones were synthesized and screened for anticancer activity by MTT assay. The compounds were evaluated against two cancerous cell lines BT549 (human breast carcinoma), HeLa (human cervical carcinoma), and one noncancerous cell line vero (normal kidney epithelial cells). 3b was found to be the most active molecule against BT549 cells (IC₅₀?=?20.1?µM) and 3h against HeLa cells (IC₅₀?=?20.45?µM). 3b also exhibited moderate activity against HeLa cells (IC₅₀?=?42.8?µM). The molecular structures of 3h and 3i were solved by single crystal X-ray crystallographic technique. Additionally, the molecular docking studies between the tumour suppressor protein p53 with the lead compound 3h, which exhibited better anticancer activity against HeLa cells was examined.     

Synthesis and biological activity of pyrazolo[3,4-d]thiazolo[3,2-a]pyrimidin-4-one derivatives: in silico approach

Xanthine oxidase (XO) is responsible for the pathological condition called gout. Inhibition of XO activity by various pyrazolo[3,4-d]thiazolo[3,2-a]pyrimidine-4-one derivatives was assessed and compared with the standard inhibitor allopurinol. Out of 10 synthesized compounds, two compounds, viz. 3-amino-6-(2-hydroxyphenyl)-1H-pyrazolo[3,4-d]thiazolo[3,2-a]pyrimidin-4-one (3b) and 3-amino-6-(4-chloro-2-hydroxy-5-methylphenyl)-1H-pyrazolo[3,4-d]thiazolo[3,2-a]pyrimidin-4-one (3g) were found to have promising XO inhibitory activity of the same order as allopurinol. Both compounds and allopurinol inhibited competitively with comparable Ki (3b: 3.56?µg, 3g: 2.337?µg, allopurinol: 1.816?µg) and IC₅₀ (3b: 4.228?µg, 3g: 3.1?µg, allopurinol: 2.9?µg) values. The enzyme–ligand interaction was studied by molecular docking using Autodock in BioMed Cache V. 6.1 software. The results revealed a significant dock score for 3b (?84.976?kcal/mol) and 3g (?90.921?kcal/mol) compared with allopurinol (?55.01?kcal/mol). The physiochemical properties and toxicity of the compounds were determined in silico using online computational tools. Overall, in vitro and in silico study revealed 3-amino-6-(4-chloro-2-hydroxy-5-methylphenyl)-1H-pyrazolo[3,4-d]thiazolo[3,2–a]pyrimidin-4-one (3g) as a potential lead compound for the design and development of XO inhibitors.     

Design,Synthesis and Antibacterial Activity of Novel Pyrimidine-Containing 4H-Chromen-4-One Derivatives**

A series of pyrimidine-containing 4H-chromen-4-one derivatives were designed and synthesized by combining bioactive substructures. Preliminary biological activity results showed that most of the compounds displayed significant inhibitory activities in vitro against Xanthomonas axonopodis pv. Citri (X. axonopodis), Xanthomonas oryzae pv. oryzae (X. oryzae) and Ralstonia solanacearum (R. solanacearum). In particular, compound 2-[(3-{[5,7-dimethoxy-4-oxo-2-(3,4,5-trimethoxyphenyl)-4H-1-benzopyran-3-yl]oxy}propyl)sulfanyl]-4-(4-methylphenyl)-6-oxo-1,6-dihydropyrimidine-5-carbonitrile ( 4c ) demonstrated a good inhibitory effect against X. axonopodis and X. oryzae, with the half-maximal effective concentration (EC₅₀) values of 15.5 and 14.9 μg/mL, respectively, and compound 2-[(3-{[5,7-Dimethoxy-4-oxo-2-(3,4,5-trimethoxyphenyl)-4H-1-benzopyran-3-yl]oxy}propyl)sulfanyl]-4-(3-fluorophenyl)-6-oxo-1,6-dihydropyrimidine-5-carbonitrile ( 4h ) showed the best antibacterial activity against R. solanacearum with an EC₅₀ value of 14.7 μg/mL. These results were better than commercial reagents bismerthiazol (BT, 51.7, 70.1 and 52.7 μg/mL, respectively) and thiodiazole copper (TC, 77.9, 95.8 and 72.1 μg/mL, respectively). In vivo antibacterial activity results indicated that compound 4c displayed better curative (42.4 %) and protective (49.2 %) activities for rice bacterial leaf blight than BT (35.2, 39.1 %) and TC (30.8, 27.3 %). The mechanism of compound 4c against X. oryzae was analyzed through scanning electron microscopy (SEM). These results indicated that pyrimidine-containing 4H-chromen-4-one derivatives have important value in the research of new agrochemicals.     

Discovery of novel 4-anilinoquinazoline derivatives as potent inhibitors of epidermal growth factor receptor with antitumor activity

Two new series of new compounds containing a 6-amino-substituted group or 6-acrylamide-substituted group linked to a 4-anilinoquinazoline nucleus have been discovered as potential EGFR inhibitors. These compounds proved efficient effects on antiproliferative activity and EGFR–TK inhibitory activity. Especially, N⁶-((5-bromothiophen-2-yl)methyl)-N⁴-(3-chlorophenyl)quinazoline-4,6-diamine (5e), showed the most potent inhibitory activity (IC₅₀ = 3.11 μM for Hep G2, IC₅₀ = 0.82 μM for A549). The EGFR molecular docking model suggested that the new compound is nicely bound to the region of EGFR, and cell morphology by Hoechst stain experiment suggested that these compounds efficiently induced apoptosis of A549 cells.     

Synthesis,Spectroscopic Analysis,and in Vitro/in Silico Biological Studies of Novel Piperidine Derivatives Heterocyclic Schiff-Mannich Base Compounds

In the present study, 3-substitued-4-(4-hydroxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones ( S1-8 ) were synthesized by treating 4-hydroxybenzaldehyde ( B ) with eight different 3-substitued-4-amino-4,5-dihydro-1H-1,2,4-triazole-5-ones ( T1-8 ) in acetic acid medium, separately. The synthesized Schiff bases ( S ) were reacted with formaldehyde and secondary amine such as 4-piperidinecarboxyamide to afford novel heterocyclic bases. 3-Substitued-4-(4-hydroxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones ( T ) were treated with 4-piperidinecarboxyamide in the presence of formaldehyde to synthesize eight new 1-(4-piperidinecarboxyamide-1-yl - methyl)-3-substitued-4-(4-hydroxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones ( M1-8 ). The structure characterization of compounds was carried out using ¹H-NMR, IR, HR-MS, and ¹³C-NMR spectroscopic methods. The inhibitory properties of the newly synthesized compounds were calculated against the acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and glutathione S-transferase (GST) enzymes. Ki values were calculated in the range of 20.06±3.11–36.86±6.17 μM for GST, 17.87±2.91–30.53±4.25 μM for AChE, 9.08±0.69–20.02±2.88 μM for BChE, respectively, Besides, IC₅₀ values were also calculated. Best binding scores of -inhibitors against used enzymes were calculated as −12.095 kcal/mol, −12.775 kcal/mol, and −9.336 kcal/mol, respectively. While 5-oxo-triazole piperidine-4-carboxamide moieties have a critical role in the inhibition of AChE and GST enzymes, hydroxy benzyl moiety is important for BChE enzyme inhibition.     

Synthesis of pyrimidin-4-one-1,2,3-triazole conjugates as glycogen synthase kinase-3β inhibitors with anti-depressant activity

GSK-3 specific inhibitors are promising candidates for the treatment of devastating pathologies such as diabetes, neurodegenerative diseases and cancers. We have synthesized a library of pyrimidin-4-one-1,2,3-triazole conjugates using click-chemistry approach and evaluated them as glycogen synthase kinase-3β inhibitors. Compounds 3g, 3j, 3n and 3r were found to be most potent among the eighteen pyrimidin-4-one-1,2,3-triazole conjugates synthesized and they were further evaluated for their in vivo anti-depressant activity. Compound 3n (2-((1-(3,4-dimethylphenyl)-1H-1,2,3-triazol-4-yl)methylthio)-3-methyl-6-phenylpyrimidin-4(3H)-one) exhibited the most potent inhibitory activity against GSK-3β with IC₅₀ value of 82 nM and was also found to exhibit significant antidepressant activity at 50 mg/kg, when compared with fluoxetine, a known antidepressant drug. The molecular docking studies were performed to elucidate the binding modes of the compounds with the GSK-3β target and two crucial interactions namely, hydrogen bond formation with Val 135 and Lys 183 residues in the active site of GSK-3β were observed.     

Exploration of N-alkyl-2-[(4-oxo-3-(4-sulfamoylphenyl)-3,4-dihydroquinazolin-2-yl)thio]acetamide derivatives as anticancer and radiosensitizing agents

Multitargeted therapy is considered a successful approach to cancer treatment. The development of small molecule multikinase inhibitors through hybridization strategy can provide highly potent and selective anticancer agents. A library of N-alkyl-2-[(4-oxo-3-(4-sulfamoylphenyl)-3,4-dihydroquinazolin-2-yl)thio]acetamide derivatives 5–18 was designed and synthesized. The synthesized compounds were screened for cytotoxic activity against MDA-MB-231 breast cancer cell line and showed IC₅₀ in the range of 0.34–149.10 µM. The inhibition percentage of VEGFR-2 was measured for all the compounds and found to be in the range of 90.09–20.44%. The promising compounds 8, 12, 13, 16 and 17 were selected to measure their possible multikinase inhibitory activity against VEGFR-2 and EGFR. IC₅₀ of the promising compounds were in the range of 247–793 nM for VEGFR-2 in reference to sunitinib (IC₅₀ 320 nM), and 369–725 nM for EGFR in reference to erlotinib (IC₅₀ 568 nM). Compounds 12 and 13 showed the most potent activity towards VEGFR-2 & EGFR, respectively. Measuring the cytotoxicity of 12 and 13 against MCF-10 normal breast cell line indicates their relative safety to normal breast cells (IC₅₀ 37 & 97 µM, respectively). As radiotherapy is considered the primary treatment for some types of solid tumors, the radiosensitizing ability of 12 and 13 was measured by subjecting the MDA-MB-231 cells to a single dose of 8 Gy of gamma radiation. IC₅₀ of 12 and 13 decreased from 1.91 & 0.51 µM to 0.79 & 0.43 µM, respectively. Molecular docking was performed to gain insights into the ligand-binding interactions of 12 inside VEGFR-2 and EGFR binding sites in comparison to their co-crystallized ligands.