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In a continuing effort for our research group, we identify new active 1,2,4-triazine derivatives as novel cancer preventive agents that target CYP1A1 activity, through the application of quantitative structure–activity relationship (QSAR) theory. For this purpose, novel fused 1,2,4-triazine derivatives, namely, 4-Amino-6-substituted benzyl-3-(2-substituted benzylidenehydrazinyl)-1,2,4-triazin-5(4H)-ones and acetylated 6-substituted benzyl-7-oxo-3-substituted phenyl-2,3-dihydro-7[Formula: see text]-[1,2,4]triazolo[4,3-[Formula: see text]][1,2,4]triazine analogs were utilized for the prediction of the QSAR model. Furthermore, the application of this QSAR equation served successfully as a rational guide for predicting the activities of newly synthesized analogs. The DFT calculation was applied to recognize the physicochemical parameters at B3LYP/6- 311G* level to gain a clear view of global and local molecular reactivity. Besides, the molecular features of the investigated compounds were identified through HOMO, LUMO and molecular electrostatic potential (MEP) which were plotted to determine the charge transfer within the molecules. Promising two novel 1,2,4-triazine compounds were identified with observed significant inhibitions (83% and 67%) and CYP1A1 activity was predicted. The chemical configuration of the two actives showed good alignment of [Formula: see text]-methoxy benzyl aminotriazinone fragments, hydrazino and carbonyl linker in structure–activity relationship and interaction. Molecular modeling analysis supported with MD simulations was undertaken to investigate different binding interactions with the target binding site. These projects offered a good application of a promising QSAR model for prediction of highly active compounds for further lead optimization.

This is a single center, retrospective, observational study carried out in Ohud hospital, the main referral hospital for SARS-CoV-2 infections in the region of Madinah, Kingdom of Saudi Arabia. The study was carried on hospitalized patients with moderate to severe symptoms, including critically ill patients in the intensive care unit mostly of them requiring oxygen or mechanical ventilator support. Medical records from 432 cases were investigated showing that the majority of infected population were adults with an average age of 48 years, where 68.3% were males and the mortality rate was 5.6%. Duration of the disease was determined as the period between the first positive and the first negative PCR results. Patients who received antibiotics or Metoclopramide showed shorter duration of the disease time course while those who received Hydroxychloroquine, Omeprazole or Calcium exhibited longer durations before obtaining a negative PCR result. Regression analysis furtherly confirmed that antibiotics administration was associated with shorter course of disease while hydroxychloroquine or omeprazole were correlated with longer duration of the disease. Antiviral drugs, however, showed no correlations to the COVID-19 duration of stay in hospital. Finally, combining antibiotics and antiviral agents did not result in a better outcome, suggesting that the use of antibacterial agents helps in the recovery of SARS-CoV-2 patients.

This work presents the combined microwave assisted synthesis, spectroscopic analyses, cytotoxic effects, and molecular docking studies of the chromene fused ring systems with various substituents of the terminal halogenated phenyl ring derivatives of 6-methoxy-4H-benzo [h]chromene (4a-m). The structures of the synthesized compounds were established on the basis of their spectral data, IR, 1H NMR, 13C NMR, 13C NMR-DEPT, and MS data. The target compounds were evaluated for their antitumor activities against three cancer cell lines: MCF-7, HCT-116, and HepG-2, in comparison to Vinblastine and Colchicine as reference drugs with the usage of a MTT colorimetric assay. The most active compounds were subjected to further mechanistic analysis through the assay of the c-Src Kinase inhibition activity. The SAR studies reported that the substitution at the 4-position of the 2-amino-4H-benzo [h]chromene nucleus with specific halogen atoms and lipophilic characters increased the ability of the molecule against the different cell lines. The Molecular Operating Environment (MOE) was used to evaluate the interactions between the ligand and the c-Src Kinase enzyme. Compound 4m, having the 3,5-dibromo-2-methoxyphenyl group attached to the 4H-benzo [h]chromene moiety at the 4-postion, exhibited a promising interaction with the c-Src Kinase, which leads to a strong inhibition of this enzyme.

A focused library of new dicationic ionic liquids (DiILs) 6–41 appended pyridinium hydrazone and phenoxy side chain hybrids as counter cations were designed and synthesized, utilizing quaternization and metathesis reactions under both conventional and microwave irradiation. The novel DiILs 6–41 were fully characterized using different spectroscopic tools (1H, 13C, 19F, 11B, 31P NMR and mass spectra) and evaluated for their antimicrobial activity against diverse types of high resistant strains including two Gram-positive bacteria; methicillin-resistant Staphylococcus aureus (MRSA), Clostridium difficile, two Gram-negative bacteria; two Escherichia coli isolates, and Neisseria gonorrhea, and fungal strain; Candida albicans. The antibacterial screening was carried out by broth microdilution method and MIC values were reported as indicator of growth inhibition. They mostly exhibited antibacterial effect against MRSA and EC strains. The effect of the synthesized ILs on Gram-positive bacteria showed the phenoxy linker chain increases, the MIC values increases with more lethal effect due to the hydrophobicity parameter. This behavior was confirmed by the molecular dynamic simulation through the interaction with surface membrane as general mechanism of ILs. The dicationic ionic liquids are considered promising motifs for further investigations with focusing on the terminal hydrophobic adjuster.

A library of novel imidazole-1,2,3-triazole hybrids were designed and synthesized based on the hybrid pharmacophore approach. Therefore, copper(I)catalyzed click reaction of thiopropargylated-imidazole 2 with several organoazides yielded two sets of imidazole-1,2,3-triazole hybrids carrying different un/functionalized alkyl/aryl side chains 4a&ndash, k and 6a&ndash, e. After full spectroscopic characterization using different spectral techniques (IR, 1H, 13C NMR) and elemental analyses, the resulted adducts were screened for their anticancer activity against four cancer cell lines (Caco-2, HCT-116, HeLa, and MCF-7) by the MTT assay and showed significant activity. In-silico molecular docking study was also investigated on one of the prominent cancer target receptors, i.e., glycogen synthase kinase-3&beta, (GSK-3&beta, ), revealing a good binding interaction with our potent compound, 4k and was in agreement with the in vitro cytotoxic results. In addition, the ADMET profile was assessed for these novel derivatives to get an insight on their pharmacokinetic/dynamic attributes. Finally, this research design and synthesis offered click chemistry products with interesting biological motifs mainly 1,2,3 triazoles linked to phenyl imidazole as promising candidates for further investigation as anticancer drugs.

A series of benzothiazole/isatin linked to 1,2,3-triazole moiety and terminal sulpha drugs 5a-e and 6a-e were synthesized and evaluated for cytotoxic activity against a panel of cancer cell lines. The novel compounds showed variable IC50 range of activity and some of them were potent compared to reference drug. The promising compounds were subjected as postulated the mimicry proposal for quinazoline-based EGFR inhibitors for their inhibitory profile against EGFR TK enzyme. That data obtained revealed that most of these compounds were potent EGFR TK inhibitors at nanomolar concentrations. Among these, compounds 5a and 5b showed more potent activity on EGFR compared to erlotinib (IC50 103 and 104 versus 67.6 nM). Based upon the results, molecular docking analysis was performed on EGFR receptor and proved the strong contribution of fragments; benzothiazole, isatin, and triazole to the binding ATP pocket. When these selected compounds 5a and 5b were tested in an HepG2 model, they could effectively inhibited tumor growth, strongly induced cancer cell apoptosis, and suppressed cell cycle progression leading to DNA fragmentation. Well-DMET profile of the most active derivatives was presented and compared to the reference drugs. Taken together, we introduced novel triazole-sulpha drug hybrid for the first time as EGFR inhibitors and the results of our studies indicate that the newly discovered inhibitors have significant potential for anticancer treatment.

This study reports an efficient and convenient click synthesis of novel series of chromene scaffold linked to 1,2,3 triazole ring and terminal lipophilic fragments. Structures of all newly synthesized compounds were well characterized by IR, 1H NMR, 13C NMR and elemental analyses. In vitro MTT cytotoxic screening was performed using staurosporine as a reference drug against three different types: aggressive and invasive human breast cancer cell line (MDA-MB 231), Michigan cancer foundation-7 (MCF-7) and human colorectal carcinoma cell line (HCT116). These screening data showed considerable anticancer activity for these newly synthesized compounds compared to reference staurosporine drug with high degree of cell line selectivity and excellent activity with micromolar (µM) half maximal inhibitory concentration (IC50) values against tumor cells. In addition, Cyclin-Dependent Kinase1 and 9 (CDK1 and 9) assays were performed for the most active compounds to get more details about their mechanism of action. In order to assess and explain their binding affinities, molecular docking simulation was studied against CDK9 site. The results obtained from molecular docking study and those obtained from cytotoxic screening and enzyme inhibition were correlated. One of the most prominent analogs is 34 that showed high selective cytotoxicity profile against single breast cancer cell line MCF-7 and MDA-MB 231 with IC50 3.4 µM and 1.4 uM respectively. Molecular dynamics (MD) simulation of the CDK9 complex by Desmond revealed stability during 100 ns with RMSD of CDK9 complex converged at 2.1 A after 20 ns. During MD, the interaction fractions confirmed multiple interactions of 34 with Cys106, a crucial residue for inhibition of CDK9 activity. A novel 34 triazole compound was introduced for drug design works as potent and selective hit for treatment of breast cancers after processing of optimization steps.

Fifteen new substituted N-2-(2-oxo-3-phenylquinoxalin-1(2H)-yl) acetamides 5a-f, 6a-f, and 8a-c were synthesized by reacting ethyl 2-(2-oxo-3-phenylquinoxalin-1(2H)-yl)acetate with various primary amines including benzylamines, sulfonamides, and amino acids. The in vitro antimicrobial screening of the target compounds was screened to assess their antibacterial and antifungal activity. As a result, seven compounds namely; 5a, 5c, 5d, 6a, 6c, 8b and 8c showed a promising broad spectrum antibacterial activity against both Gram-positive and Gram-negative strains. Among these, the analogs 5c and 6d were nearly as equiactive as ciprofloxacin drug. Meanwhile, four compounds namely; 5c, 6a, 6f and 8c exhibited appreciable antifungal activity with MIC values range 33–40 mg/mL comparable with clotrimazole (MIC 25 mg/mL). In addition, the anticancer effects of the synthesized compounds were evaluated against three cancer lines. The data obtained revealed the benzylamines and sulpha derivatives were the most active compounds especially 5f and 6f ones. Further EGFR enzymatic investigation was carried out for these most active compounds 5f and 6f resulting in inhibitory activity by 1.89 and 2.05 µM respectively. Docking simulation was performed as a trial to study the mechanisms and binding modes of these compounds toward the enzyme target, EGFR protein kinase enzyme. The results revealed good compounds placement in the active sites and stable interactions similar to the co-crystallized reference ligand. Collectively, the analogs 5f and 6f could be further utilized and optimized as good cytotoxic agents.

In our effort to develop novel and powerful agents with anti-proliferative activity, two new series of 1H-benzo[f]chromene derivatives, 4a–h and 6a–h, were synthesised using heterocyclocondensation methodologies under microwave irradiation condition. The structures of the target compounds were established on the basis of their spectral data, IR, 1H NMR, 13 C NMR, 13 C NMR-DEPT/APT, and MS data. The new compounds have been examined for their anti-proliferative activity against three cancer cell lines, MCF-7, HCT-116, and HepG-2. Vinblastine and Doxorubicin have been used as positive controls in the viability assay. The obtained results confirmed that most of the tested molecules revealed strong and selective cytotoxic activity against the three cancer cell lines. Moreover, these molecules exhibited weak cytotoxicity on the HFL-1 line, which suggested that they might be ideal anticancer candidates. The SAR study of the new benzochromene compounds verified that the substituents on the phenyl ring of 1H-benzo[f]chromene nucleus, accompanied with the presence of bromine atom or methoxy group at the 8-position, increases the ability of these molecules against the different cell lines. Due to their high anti-proliferative activity, compounds 4c and 6e were selected to be examined their proficiency to inhibit the invasiveness of the highly sensitive and invasive breast cancer cell line, MDA-MB-231. The anti-invasion behaviour of these molecules against the highly sensitive, non-oestrogen, and progesterone MDA-MB-231 cell line gave rise to their decreasing metastatic effect compared to the reference drug. Furthermore, this report explores the apoptotic mechanistic pathway of the cytotoxicity of the target compounds and reveals that most of these compounds enhance the Caspase 3/7 activity that could be considered as potential anticancer agents.

In this study, we tested two novel series of 5-arylazo-2-hydrazonothiazoles 6a–g and 2-hydrazono[1,3,4]thiadiazoles 12a–c as antimicrobial and anticancer agents. These series were prepared from the reactions of 2-{1-[4-(2,4-dihydroxyphenylazo)phenyl]ethylidene}thiosemi-carbazide (3) with α-keto hydrazonoyl halides and N-aryl arenecarbohydrazonoyl halides. The structures of the newly synthesized compounds were elucidated by infrared, 1H and 13C nuclear magnetic resonance, and gas chromatography mass spectrometry spectral data. The antibacterial activity against two types of Gm +ve bacteria and, two types for Gm –ve bacteria, and the antifungal activity against four fungi microorganisms were evaluated by a well diffusion method for the synthesized compounds. Of these novel compounds, thiazole derivatives 6a–g showed mostly promising antibacterial activity against Gm +ve strains and antifungal activity compared to the reference drugs. A successful step was achieved to explain of their mode of action through molecular docking of the most active molecules at a target enzyme, CYP51. Moreover, the antiproliferative activity was tested against three human carcinoma cell lines [human colon carcinoma (HCT-116), human breast adenocarcinoma (MCF-7), and human liver carcinoma (HEPG-2)], showing promising anticancer activities compared to the doxorubicin drug. The data suggest that the arylthiazole scaffold derivatives 6a–g exhibited good antimicrobial and anticancer activities and might be used as leads for further optimization.

Thiazole derivatives are known to possess various biological activities such as antiparasitic, antifungal, antimicrobial and antiproliferative activities. Matrix metalloproteinases (MMPs) are important protease target involved in tumor progression including angiogenesis, tissue invasion, and migration. Therefore, MMPs have also been reported as potential diagnostic and prognostic biomarkers in many types of cancer. Herein, new aryl thiazoles were synthesized and evaluated for their anticancer effects on a panel of cancer cell lines including the invasive MDA-MB-231 line. Some of these compounds showed IC50 values in the submicromolar range in anti-proliferative assays. In order to examine the relationship between their anticancer activity and MMPs targets, the compounds were evaluated for their inhibitory effects on MMP-2 and 9. That data obtained revealed that most of these compounds were potent dual MMP-2/9 inhibitors at nanomolar concentrations. Among these, 2-(1-(2-(2-((E)-4-iodobenzylidene)hydrazineyl)-4-methylthiazol-5-yl)ethylidene)hydrazine-1-carboximidamide (4a) was the most potent non-selective dual MMP-2/9 inhibitor with inhibitory concentrations of 56 and 38 nM respectively. When compound 4a was tested in an MDA-MB-231, HCT-116, MCF-7 model, it effectively inhibited tumor growth, strongly induced cancer cell apoptosis, inhibit cell migration, and suppressed cell cycle progression leading to DNA fragmentation. Taken together, the results of our studies indicate that the newly discovered thiazole-based MMP-2/9 inhibitors have significant potential for anticancer treatment.

A series of novel 2-Amino-4-Methylthiazole analogs were developed via three-step reaction encompassing hydrazine-1-carboximidamide motif to combat Gram-positive and Gram-negative bacterial and fungal infections. Noticeably, the thiazole-carboximidamide derivatives 4a-d displayed excellent antimicrobial activity and the most efficacious analogue 4d with MIC/MBC values of 0.5 and 4 μg/mL, compared to reference drugs with very low toxicity to mammalian cells, resulting in a prominent selectivity more than 100 folds. Microscopic investigation of 4d biphenyl analogue showed cell wall lysis and promote rapid bactericidal activity though disrupting the bacterial membrane. In addition, an interesting in vitro investigation against GlcN-6-P Synthase Inhibition was done which showed potency in the nanomolar range. Meanwhile, this is the first study deploying a biomimicking strategy to design potent thiazole-carboximidamides that targeting GlcN-6-P Synthase as antimicrobial agents. Importantly, Molecular modeling simulation was done for the most active 4d analogue to study the interaction of this analogue which showed good binding propensity to glucosamine binding site which support the in vitro data.

Novel task dicationic ionic liquids (Ts-DiILs) 6–29 were designed and synthesized, under both conventional and microwave conditions; through molecular hybridization of the appropriate bispyridines having a hydrazone linkage as spacer with some alkyl functionalized esters forming the counter cations. Beside the synthesized halogenated DiILs 6–11, fluorinated metal anions were introduced via metathesis reaction in order to create new dipyridinium ionic liquid-hydrazone hybrids 12–29. All newly synthesized DiILs were fully characterized using different spectroscopic tools such as 1H, 13C, 19F, 31P, 11B NMR and Mass experiment. The DNA binding, anticancer and docking studies of the synthesized ionic liquids were also carried out. The DNA binding constants ranged from 4.5 × 104 to 7.2 × 104 M−1, indicating good DNA binding tendencies. The most active ionic liquids were 28 and 29 with 99.99 and 99.86% anticancer activities, respectively. The docking studies indicated DNA binding in the outer grooves of DNA. The reported ionic liquids may be used as future anticancer drugs.

This study reports an efficient and convenient regioselective synthesis of a novel series of S- and S,N-bis(acyclonucleoside) analogues carrying 5-(2-chlorophenyl)-2,4-dihydro-1,2,4-triazole-3-thione. A facile and straightforward synthesis of thiazolotriazole and triazolothiazines has also been reported. Structures of all newly synthesized compounds were well characterized by infrared IR, 1H and 13C nuclear magnetic resonance (NMR) and mass (MS) spectra analyses. Cytotoxic screening was performed according to (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium (MTT) assay method using staurosporine as a reference drug against three different types: human liver cancer cell line (Hep G2), Michigan cancer foundation-7 (MCF-7) and human colorectal carcinoma cell line (HCT116). These data showed considerable anticancer activity for these newly synthesized compounds. Biological data for most of the S-acyclonucleoside analogues and S,N-bis(acyclonucleoside) analogues showed excellent activity with micromolar (µM) half maximal inhibitory concentration (IC50) values against tumor cells. EGFR assay and tubulin inhibition assay analysis were performed for the most active compounds to get more details about their mechanism of action. In order to assess and explain their binding affinities, molecular docking simulation was studied against EGFR and tubulin binding sites. The results obtained from molecular docking study and those obtained from cytotoxic screening were correlated. Extensive structure activity relationship (SAR) analyses were also carried out.

A series of new fluoroquinazolinone 6&ndash, 8 and 10a&ndash, g derivatives was designed, prepared and screened for their in vitro cytotoxic activity against human cancer cell lines MCF-7 and MDA-MBA-231. Compounds 6 (IC50 = 0.35 &plusmn, 0.01 &micro, M), 10f (IC50 = 0.71 &plusmn, M), 10d (IC50 = 0.89 &plusmn, 0.02 &micro, M) and 10a (IC50 = 0.95 &plusmn, M) displayed broad spectrum anticancer activity better than the reference drug gefitinib (IC50 = 0.97 &plusmn, M) against MCF-7. Compounds 10e (IC50 = 0.28 &plusmn, M), 10d (IC50 = 0.38 &plusmn, M), 7 (IC50 = 0.94 &plusmn, 0.07 &micro, M) and 10c (IC50 = 1.09 &plusmn, M) showed better activity than the reference gefitinib (IC50 = 1.30 &plusmn, 0.04 &micro, M) against MDA-MBA-231. Moreover, EGFR and tubulin inhibition assays were performed for the highest active derivatives and showed remarkable results comparing to the reference drugs. In order to assess and explain their binding affinities, molecular docking simulation was studied against EGFR and tubulin binding sites. The results obtained from molecular docking study and those obtained from cytotoxic screening were correlated.

Some novel anthranilate diamides derivatives 4a–e, 6a–c and 9a–d were designed and synthesized to be evaluated for their in vitro anticancer activity. Structures of all newly synthesized compounds were confirmed by infra-red (IR), high-resolution mass (HR-MS) spectra, 1H nuclear magnetic resonance (NMR) and 13C nuclear magnetic resonance (NMR) analyses. Cytotoxic screening was performed according to (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium (MTT) assay method using erlotinib as a reference drug against two different types of breast cancer cells. The molecular docking study was performed for representative compounds against two targets, epidermal growth factor receptor (EGFR) and tubulin in colchicine binding site to assess their binding affinities in order to rationalize their anticancer activity in a qualitative way. The data obtained from the molecular modeling was correlated with that obtained from the biological screening. These data showed considerable anticancer activity for these newly synthesized compounds. Biological data for most of the anthranilate diamide showed excellent activity with nanomolar or sub nanomolar half maximal inhibitory concentration (IC50) values against tumor cells. EGFR tyrosine kinase (TK) inhibition assay, tubulin inhibition assay and apoptosis analysis were performed for selected compounds to get more details about their mechanism of action. Extensive structure activity relationship (SAR) analyses were also carried out.

A series of hybrid of triazoloquinoxaline-chalcone derivatives 7a–k were designed, synthesized, fully characterized, and evaluated for their cytotoxic activity against three target cell lines: human breast adenocarcinoma (MCF-7), human colon carcinoma (HCT-116), and human hepatocellular carcinoma (HEPG-2). The preliminary results showed that some of these chalcones like 7b–c, and 7e–g exhibited significant antiproliferative effects against most of the cell lines, with selective or non-selective behavior, indicated by IC50 values in the 1.65 to 34.28 µM range. In order to investigate the mechanistic aspects of these active compounds, EGFR TK and tubulin inhibitory activities were measured as further biological assays. The EGFR TK assay results revealed that the derivatives 7a–c, 7e, and 7g could inhibit the EGFR TK in the submicromolar range (0.093 to 0.661 µM). Moreover, an antitubulin polymerization effect was noted for the active derivatives compared to the reference drug colchicine, with compounds 7e and 7g displaying 14.7 and 8.4 micromolar activity, respectively. Furthermore, a molecular docking study was carried out to explain the observed effects and the binding modes of these chalcones with the EGFR TK and tubulin targets.

A number of new L- or LD-2-amino acid ester-(substituted)-benz[1,3]oxazines 12–17 were synthesized from the reaction of free L- or LD-amino acid ester 9a–d with 2-methylthio-1,3-benzoxazines 11a–g. The structures of the new products 12–17 were confirmed from their 1H, 13CNMR and IR spectra and CHN microanalysis. Some of these compounds weakly inhibited DNA-PK and platelet aggregation. Studies of the toxicity for some of the new compounds showed mostly no inhibitory effects on HeLa cell growth at 1 and 10 µM and some up to 40 µM. The chemo-sensitization to etoposide by some of the compounds revealed that the most effective chemo-sensitizers at 10 µM were 14c (1.83 fold), 12e (1.42 fold), 15a (0.8 fold), 16d (0.76 fold) and 1c (0.74). However, at 1 µM in the presence of etoposide, some compounds were shown to be more effective. No direct link was observed between the type of the L-amino acid methyl ester as well as the 7-, 8-, or 7, 8-substitution on the aromatic ring on the effectiveness of the chemo-sensitizers; however, the 7-hydroxy group did lower the effective chemo-sensitizers values.

Drugs of cancer based upon ionizing radiation or chemotherapeutic treatment may affect breaking of DNA double strand in cell. DNA-PK enzyme has emerged as an attractive target for drug discovery efforts toward DNA repair pathways. Hence, the search for potent and selective DNA-PK inhibitors has particularly considered state-of-the art and several series of inhibitors have been designed. In this article, a novel benchmark DNA-PK database of 43 compounds was built and described. Ligand-based approaches including pharmacophore and QSAR modeling were applied and novel models were introduced and analyzed for predicting activity test for DNA-PK drug candidates. Based upon the modeling results, we gave a report of synthesis of fifteen novel 2-((8-methyl-2-morpholino-4-oxo-4 H -benzo[ e ][1,3]oxazin-7-yl)oxy)acetamide derivatives and in vitro evaluation for DNA-PK inhibitory and antiproliferative activities. These fifteen compounds overall are satisfied with Lipinski's rule of five. The biological testing of target compounds showed five promising active compounds 7c , 7d , 7f , 9e and 9f with micromolar DNA-PK activity range from 0.25 to 5 µM. In addition, SAR of the compounds activity was investigated and confirmed that the terminal aryl moiety was found to be quite crucial for DNA-PK activity. Moreover flexible docking simulation was done for the potent compounds into the putative binding site of the 3D homology model of DNA-PK enzyme and the probable interaction model between DNA-PK and the ligands was investigated and interpreted.

Some novel fluorinated quinazolines (5a–j) were designed and synthesized to be evaluated for their anticonvulsant activity and their neurotoxicity. Structures of all newly synthesized compounds were confirmed by their infrared (IR), mass spectrometry (MS) spectra, 1H nuclear magnetic resonance (NMR), 13C-NMR, and elemental analysis (CHN). The anticonvulsant activity was evaluated by a subcutaneous pentylenetetrazole (scPTZ) test and maximal electroshock (MES)-induced seizure test, while neurotoxicity was evaluated by a rotorod test. The molecular docking was performed for all newly-synthesized compounds to assess their binding affinities to the GABA-A receptor in order to rationalize their anticonvulsant activities in a qualitative way. The data obtained from the molecular modeling was correlated with that obtained from the biological screening. These data showed considerable anticonvulsant activity for all newly-synthesized compounds. Compounds 5b, 5c, and 5d showed the highest binding affinities toward the GABA-A receptor, along with the highest anticonvulsant activities in experimental mice. These compounds also showed low neurotoxicity and low toxicity in the median lethal dose test compared to the reference drugs. A GABA enzymatic assay was performed for these highly active compounds to confirm the obtained results and explain the possible mechanism for anticonvulsant action. The most active compounds might be used as leads for future modification and optimization.

The 2-morpholino-substituted-benzoxazines 7a and 7b were used in the synthesis of 2-morpholino-di-O-benzyl, O-pyridin-2yl, 3-yl and 4yl-methoxy)-1,3-benzoxazines 8a–8d, and N-(2-morpholino-4-oxo-4H-benz[e][1,3]oxazin-7-yl)-N-(pyridin-2-and-3-ylmethyl)acetamides 8e and 8f. The DNA-dependent protein kinase (DNA-PK) and phosphatidylinositol 3-kinase (PI3K) α, β, γ, and δ isoforms were studied for the new compounds 8a–8f and PI3K for the 18 previously synthesized compounds 9–26. The most active DNA-PK inhibitors were the 2-morpholino-O-substituted linear or angular naphthoxazine compounds 18–20 and 21–22 which showed potent and selective DNA-PK activity (IC50 from 0.01 to 2.43 µM) over PI3K. 8-(2-(4-Methylpiperazin-1-yl)ethoxy)-2-morpholino compound 13, and 8-methyl-2-(pyridin-3-yl(pyridin-3-ylmethyl)amino)-7-(pyridin-3-ylmethoxy) compound 25 showed selective DNA-PK inhibition. 2-morpholino-8-substituted-benzoxazine 9 (8-ph) and 10–12 (8-(pyridine-2-, 3-, or 4-ylmethoxy) showed high-to-moderate inhibition of PI3K and DNA-PK. A similar pattern for DNA-PK nonselectivity over PI3K was observed for compounds with 7,8-O-bis-substituted 8a, 8c, and 8d. No DNA-PK selectivity over PI3K was observed regardless whether the substitution was phenyl, pyridin-2-ylmethoxy, pyridin-3-ylmethoxy, and pyridin-4-ylmethoxy.

The DNA dependant protein kinase (DNA-PK) enzyme plays a major part in the repair of double stranded breaks induced by radiation and hence in the radio-resistance of tumour cells. Inhibitors of DNA-PK have been tested successfully in the past for their ability to sensitize cancer cells to the effects of radiation. Here we present a novel benzoxazine, 8-methyl-2-(morpholine-4yl)-7-(pyridine-3-methoxy)-4H-1,3-benzoxacine-4-one (LTU27) and analyse its ability to cause sensitization of lung cancer and colon cancer cells to radiation. There was a significant reduction in survival rate, increase in apoptosis and inhibition in autophosphorylation of DNA-PK and AKT1 after treating them concomitantly with both radiation and LTU27. The mechanism of action appears to be through inhibition of DNA-PK leading to delayed DNA repair and promotion of apoptosis.

This report presents the development of a novel and primary model of sulfonamide compounds encompassing a chromene azo motif with the intent of becoming applicable for drug candidates in the cases of drug-resistant pathogens. The novel molecules (7a–n) have been synthesized via a two-step reaction. First, 4-((2, 4-dihydroxyphenyl)diazenyl)benzenesulfonamide (3a–e) were obtained through the reaction of their corresponding diazotized 4-aminobenzenesulfonamides (1a–e) with resorcinol, followed by the heterocyclization of 3a–e with arylidenemalononitriles (6a–d). Upon structural identification, the newly synthesized compounds were evaluated for their antibacterial and antifungal activities. Moreover, their cytotoxic screening was performed against three cancer cell lines: HCT-116, HepG-2, and MCF-7. Further examinations were comprised of the inhibitory effect analyses of the novel sulfonamide/chromene derivatives against the HDAC classes and the Tubulin polymerization in order to discern the prime antitumor drug candidates.

Summary The benzoaxines have been developed from structurally similar chromones as specific inhibitors of the PI3K family to sensitize cancer cells to the effects of chemotherapeutic agents; most have been shown to do this through specific inhibition of DNA-PK and DNA repair mechanisms. In this study we examined the benzoxazine, 2-((3-methoxybut-3en-2-yl)amino)-8methyl-4H-benzo[1,3]oxazin-4one (LTUSI54). This compound had no DNA-PK or PI3K inhibitory activity but still sensitized HeLa cells to the effects of Etoposide. LTUSI54 works synergistically with Etoposide to inhibit growth of HeLa cells and sub G1 analysis indicates that this is not due to an increase in apoptosis. LTUSI54 neither enhances DSB formation due to Etoposide nor does it delay the repair of such damage. Cell cycle analysis shows a clear G2 block with Etoposide alone while, in combination with LTUSI54 there is an additional S phase arrest. Phospho-kinase analysis indicated that LTUSI54 engages key regulators of cell cycle progression, specifically p38α, p53 and ERK 1/2. From our results we hypothesize that LTUSI54 is promoting the cell cycle arrest through activation of p38α pathways, independent of p53 mechanisms. This results in a decrease in p53 phosphorylation and hence, restricted apoptosis. Changes in cell number appear to be the result of p38α pathways disrupting cell cycle progression, at the S and G2 checkpoints. Further investigation into the finer mechanisms by which LTUSI54 effects cell cycle progression would be of great interest in assessing this compound as a chemosensitising agent.

The main step in a successful drug discovery pipeline is the identification of small potent compounds that selectively bind to the target of interest with high affinity. However, there is still a shortage of efficient and accurate computational methods with powerful capability to study and hence predict compound selectivity properties. In this work, we propose an affordable machine learning method to perform compound selectivity classification and prediction. For this purpose, we have collected compounds with reported activity and built a selectivity database formed of 153 cathepsin K and S inhibitors that are considered of medicinal interest. This database has three compound sets, two K/S and S/K selective ones and one non-selective KS one. We have subjected this database to the selectivity classification tool ‘Emergent Self-Organizing Maps’ for exploring its capability to differentiate selective cathepsin inhibitors for one target over the other. The method exhibited good clustering performance for selective ligands with high accuracy (up to 100 %). Among the possibilites, BAPs and MACCS molecular structural fingerprints were used for such a classification. The results exhibited the ability of the method for structure-selectivity relationship interpretation and selectivity markers were identified for the design of further novel inhibitors with high activity and target selectivity.

A number of new 2-(pyridin-3-ylamino)-4H-(substituted) benz[e]-1,3-oxazin-4-ones were synthesized 10a–g. These were then reacted with the hydro-halogen salt of 2, 3 and 4-(halo-methyl) pyridine in the presence of Cs2CO3 to give eighteen new 2-(N-substituted (pyridin-3-ylmethyl) amino)-substituted-1,3-benzoxazines (compounds 11a–i, 13a–c, and 15a–f). X-ray crystallography was used to confirm that the 2-N-substituted structures 11 and 13 were formed rather than the 3-N-substitution analogues 12 and 14. Eleven of the new compounds were tested for their effect on collagen induced platelet aggregation and it was found that the most active inhibitory compound was 8-methyl-2-(pyridin-3-yl(pyridin-3-ylmethyl)amino)-7-(pyridin-3-ylmethoxy)-4H-benz[e]-1,3-oxazin-4-one 15e with an IC50 of 10 ± 2 μM. DNA-dependent protein kinase (DNA-PK) inhibition data for 12 previously prepared 2-morpholino substituted-1,3-benzoxazines (compounds 19–31) were measured and showed high to moderate activity where the most active compound was compound 27 with an IC50 of 0.28 μM. Furthermore DNA-PK inhibition data for six newly prepared 2-(N-substituted (pyridin-3-ylmethyl) amino)-substituted-1,3-benzoxazines (compounds 11b, 13a–b, 15a–b and 15e) and 8-methyl-7-(pyridin-3-ylmethoxy)-3-(pyridin-3-ylmethyl)-2H-benz[e]-1,3-oxazin-2,4(3H)-dione 17d were measured and moderate to low inhibitory activity was observed, with the most active of the compounds in this series being 8-methyl-2-(pyridin-3-yl(pyridin-3-ylmethyl)amino)-7-(pyridin-3-ylmethoxy)-4H-benz[e]-1,3-oxazin-4-one 15e with an IC50 of 2.5 μM. PI3K inhibition studies revealed that compound 27 is highly potent (IC50 for PI3Kα = 0.13 μM, PI3Kβ = 0.14 μM, PI3Kγ = 0.72 μM, PI3Kδ = 2.02 μM). Compound 22 with 7-[2-(4-methylpiperazin-1-yl)ethoxy] group shows greater inhibition of DNA-PK over PI3K. Docking of some 2-morpholino-substituted-1,3-benzoxazine compounds 19–31 within the binding pocket and structure–activity relationship s (SAR) analyses were performed with results agreeing well with observed activities.

A number of new angular 2-morpholino-(substituted)-naphth-1,3-oxazines (compound 10b), linear 2-morpholino-(substituted)-naphth-1,3-oxazines (compounds 13b-c), linear 6, 7 and 9-0-substituted-2-morpholino-(substituted)-naphth-1,3-oxazines (compounds 17-22, 24, and 25) and angular compounds 14-16 and 23 were synthesised. The O-substituent was pyridin-2yl-methyl (15, 18, and 21) pyridin-3yl-methyl (16, 19, and 22) and 4-methylpipreazin-1-yl-ethoxy (23-25). Twelve compounds were tested for their inhibitory effect on collagen induced platelet aggregation and it was found that the most active compounds were compounds 19 and 22 with IC(50) = 55 +/- 4 and 85 +/- 4 mu M, respectively. Furthermore, the compounds were also assayed for their ability to inhibit DNA-dependent protein kinase (DNA-PK) activity. The most active compounds were 18 IC(50) = 0.091 mu M, 24 IC(50) = 0.191 mu M, and 22 IC(50) = 0.331 mu M. Homology modelling was used to build a 3D model of DNA-PK based on the X-ray structure of phosphatidylinositol 3-kinases (PI3Ks). Docking of synthesised compounds within the binding pocket and structure-activity relationships (SAR) analyses of the poses were performed and results agreed well with observed activity.

A number of new 2-amino-[5, 6, 7 and 8]-O-substituted 1,3-benzoxazines, and 2-amino 8-methyl-7-O-substituted-1,3-benzoxazines were synthesized. Thirty one new compounds were tested for their effect on collagen induced platelet aggregation and it was found that the most active compounds were 8-methyl-2-morpholin-4-yl-7-(pyridin-3-ylmethoxy)-4H-1,3-benzoxazin-4-one 9f and 8-methyl-2-morpholin-4-yl-7-(pyridin-4-ylmethoxy)-4H-1,3-benzoxazin-4-one 9j with IC(50) = 2 ± 1.5 and 4 ± 2 μM respectively. Inhibition of DNA-PK activity at concentrations of 1.6-4 μM were tested for 9 products 5i, 7a-e and 9b, 9f and 9j.

New N-(benzyl carbamothioyl)-2-hydroxy substituted benzamides13,20, and21were synthesized using sodium bicarbonate and benzyl amine with 2-thioxo-substituted-1,3-benzoxazines6, 10a, b, 11c, and12a–n. The 2-thioxo-substituted-1,3-oxazines6, 10a-b, 11d 12a–n, and26were converted to the corresponding 2-methylthio-substituted-1,3-oxazines14a–land24which were then converted to 2-benzyl amino-substituted-benzoxazines15a–iby refluxing with benzylamine. Products15a, b, e, f, andgwere also synthesized by boiling the corresponding N-(benzyl carbamothioyl)-2-hydroxy substituted benzamides13a, b, f, l, andmin acetic acid. 2-Oxo-substituted-1,3-benzoxazines22and25were prepared by treating the corresponding 2-methylthio-substituted-1,3-oxazines14and24with dilute HCl. The N-(benzyl carbamoyl)-2-hydroxy substituted benzamide23was synthesized from the reaction of 2-oxo-substituted-1,3-benzoxazine22with benzylamine. The new products were characterized using IR,1H, and13C NMR in addition to microanalysis. Selected compounds were tested in vitro for antibacterial and antifungi activity and the most active compounds were found to be the 4-(substituted-benzylamino)-2-hydroxy benzoic acids9aandd(M. chlorophenolicum, MIC 50 and 25 µgm L−1, resp.),N1,N3-bis (benzyl carbamothioyl)-4,6-dihydroxy-substituted phthalamides20aand20c(B. subtilisMIC 12.5, 50 µgm L−1, resp.) and21(M. chlorophenolicum, MIC 50 µgm L−1).

A small library of novel 1,3-benzoxazine derivatives is prepared and the DNA-PK, PI3K, and platelet inhibitory activity of these substances is evaluated.

Objectives The aim of the present research was to synthesise several novel fluorinated quinazoline–sulphonamide derivatives and to evaluate their in vitro cytotoxic activity. Methods Eight compounds were synthesised. The compounds' anticancer activities were determined through the [3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide] (MTT) assay using a three-cell-line panel consisting of National Cancer Institute (NCI) lung cancer cells, Michigan Cancer Foundation-7 (MCF-7) breast cancer cells, and Human Embryonic Kidney-293 (HEK-293) normal kidney cell. The values of C log P correlations were determined to interpret the results. Results One compound exhibited significant anticancer activity with low toxicity compared with the methotrexate as the reference drug. The biological screening showed good to moderate anticancer activity for the title compounds compared with the reference drug. The reference drug exhibited an IC 50 value of 2.4 μM, whereas compound 9, which was identified as the most active compound, exhibited an IC 50 value of 2.51 μM on the NCI cell line. The other compounds showed IC 50 values that ranged from 2.89 to 46.34 μM on the three cell lines. The newly synthesized compounds had lower toxicity on the normal cell line than did methotrexate. Conclusions The newly synthesized compounds may provide a valuable template for future design and optimization to produce analogues that act as more active anticancer agents.