Utility of sulfachloropyridazine in the synthesis of novel anticancer agents as antiangiogenic and apoptotic inducers.

In a search for new anticancer agents with better activity and selectivity, the present work described the synthesis of several new series of sulfachloropyridazine hybrids with thiocarbamates 3a-e, thioureids 4a-h, 5a-e and 4-substituted sulfachloropyridazines 6a, b, 7a, b and 8. The synthesized compounds were screened in vitro against a panel of 60 cancer cell lines in one dose assay. The most potent derivatives 3a, 3c, 4c, 4d, 5e, 7a and 7b were tested for their antiangiogenic activity by measuring their ability to inhibit VEGFR-2. The most potent compounds in VEGFR-2 inhibitory assay were further evaluated for their ability to inhibit PDGFR. In addition, the ability of 4c compound to inhibit cell migration on HUVEC cells and cell cycle effect on UO-31 cells has been studied. The pro-apoptotic effect of compound 4c was studied by the evaluation of caspase-3, Bax and BCl-2. Alternatively, the IC50 of compounds 3a, 3c, 4c, 5e, 7a and 7b against certain human cancer cell lines were determined. Re-evaluation in combination with γ-radiation was carried out for compounds 4c, 5e and 7b to study the possible synergistic effect on cytotoxicity. Docking studies of the most active compounds were performed to give insights into the binding mode within VEGFR-2 active site.

Quinazolinone derivatives as new potential CDK4/6 inhibitors, apoptosis inducers and radiosensitizers for breast cancer.

Background: Targeting CDK4/6 has advanced breast cancer treatment. Herein, new quinazolinones were synthesized with acetamide linkers as potential anti-breast cancer agents. Methods & results: In vitro cytotoxic evaluation on human breast cancer cell lines (MCF7 and MDA-MB-231) identified 1,3-benzodioxole (5d) to be of the highest potency. It showed good inhibitory activity on CDK4/6. Compound 5d arrested the cell cycle at the G1-phase, caused induction of early and late apoptosis in an Annexin V-FITC assay, led to an increase in the level of caspase-3 and upregulated Bax expression and downregulated Bcl-2 in MCF7 cells. Compound 5d showed good radiosensitizing activity when combined with a single dose of 8-Gy γ-radiation. Conclusion: This study introduces quinazolinone scaffolds as new CDK4/6 inhibitors for breast cancer.

Pyrazole-sulfonamide scaffold featuring dual-tail strategy as apoptosis inducers in colon cancer.

Dual-tail strategy has been successfully utilized in the development of novel carbonic anhydrase IX (CA IX) inhibitors. Herein we adopted this approach in the design and synthesis of a series of novel pyridine sulfonamide-pyrazole hybrid scaffold mimicking dual-tail inhibitors of CA IX. A library of 15 compounds was synthesized and assessed for their potential cytotoxic effects against colorectal cancer cells. Compounds 3, and 11 induced potential cytotoxic effects against the three cancer cell lines (HCT-116, HT-29, and SW-620) with IC50s' of 45.88, 28.27, and 16.57 uM, 25.01, 8.99, and 3.27 µM, respectively. Both compounds induced cellular apoptosis on HCT-116 and SW-620 cells, while compound 3 induced necrosis as well. In addition, both compounds induced cell cycle arrest on G0/G1, and S phases. Also, compound 11 showed potential autophagy induction on both colon cancer cell lines (HCT-116, and HT-29), and a little bit on metastatic type. Both compounds were less cytotoxic than the reference drug on normal epithelial cell. The migration rates of HCT-116 and the metastatic one SW-620 were reduced by both compounds. Finally, molecular docking of compounds 3 and 11 into the active site of CA IX confirmed in vitro inhibitory activity for both compounds.

Computational, in vitro and radiation-based in vivo studies on acetamide quinazolinone derivatives as new proposed purine nucleoside phosphorylase inhibitors for breast cancer.

The present work describes a quinazolinone-based lead optimization for the development of novel purine nucleoside phosphorylase (PNP) inhibitors with quinazolinone scaffold. Nineteen compounds were proposed and docked against PNP, the best 14 compounds with highest docking and affinity scores and low RMSD values were synthesized. Synthesis of new quinazolinone derivatives with variable acetamide substituents on two positions on quinazoline ring was performed. The structures assigned to the products were concordant with the microanalytical and spectral data. In vitro cytotoxicity on human breast cancer cell line (MCF7) was performed and identified compound 6g as the most potent with IC50 (0.99 ± 0.11 µM) which was further tested against five different breast cancer cell lines in addition to normal breast cell to determine the selectivity. Compound 6g was subjected to molecular dynamic simulation study, radiolabelling and biodistribution study to investigate its stability and selectivity toward breast cancers. The in vitro PNP inhibition results were aligned with the in silico, cytotoxicity, and biodistribution results where 6g showed the most potent PNP inhibitory activity with IC50 (0.159 ± 0.007 µM) when compared to Peldesine (BCX-34) IC50 (0.041 ± 0.002 µM).

Antiproliferative, antiangiogenic and apoptotic effect of new hybrids of quinazoline-4(3H)-ones and sulfachloropyridazine.

Three new sets of quinazolinones bearing sulfachloropyridazine 4a-f, 6a-i and 8a-i were designed and synthesized. All the synthesized compounds were screened for their in vitro cytotoxicity against a panel of 60 cancer cell lines. The most potent compounds 4b, 4d, 6f, 6g, 8c, 8f and 8g were evaluated as VEGFR-2 inhibitors. Compounds 8f, 8c and 6f were the most active with IC50 = 66 ± 0.002, 108 ± 0.004 and 146 ± 0.006 nM, respectively. Compound 8f showed also moderate inhibition against PDGFR (IC50 = 180 ± 0.009 nM), EGFR (IC50 = 98 ± 0.004 nM), FGFR-1 (IC50 = 82 ± 0.004 nM) and ability to reduce migration of cells in wound healing assay. Compound 8f showed cell cycle arrest at S-phase and induced early and late apoptosis in Annexien V-FITC assay. In addition, compound 8f increased the level of caspase-3 and up regulate Bax expression and down regulate Bcl-2 in UO-31 cells. The cytotoxicity of compounds 6f, 6g and 8f against UO-31 and melanoma cells was slightly affected by combination with γ-radiation. Also, compound 8f showed low toxicity against human normal renal (RPTEC) cell line. Docking studies of the most potent compounds 4b, 4d, 6f, 6g, 8c, 8f and 8g were performed to have more insights on their binging mode within VEGFR-2 active site.

Green synthesis of novel antifungal 1,2,4-triazoles effective against γ-irradiated Candida parapsilosis.

This study reports the green synthesis of 11 novel 3-substituted-4-amino-5-mercapto-1,2,4-triazole derivatives using water as a readily available nontoxic solvent. Evaluation of their antimicrobial potential against several clinical pathogenic microorganisms was carried out. The newly synthesized cysteine derivative 6 showed promising antifungal activity against both γ-irradiated and nonirradiated Candida parapsilosis 216, with the lowest MIC (minimum inhibitory concentration) value of 3.125 µg/ml, probably through inhibition of 14α-demethylase. In addition, compound 6 showed complete inhibition of gelatinase, a virulence enzyme of C. parapsilosis. Also, scanning electron microscopy was carried out. Interestingly, compound 6 acted as a dual agent as it also showed good antibacterial activity against strains of Gram-positive bacteria used in the study. The synthesized compounds showed no cytotoxicity.

Anti-inflammatory and analgesic effect of LD-RT and some novel thiadiazole derivatives through COX-2 inhibition.

Generally, highly selective COX-2 inhibitors cause cardiovascular side effects. Celecoxib is the highly marketed coxib, so there is still a need for the synthesis of COX-2 inhibitors with less adverse effects. Moreover, low-dose radiotherapy (LD-RT) is clinically used for the treatment of inflammatory diseases. The present study aimed to investigate the analgesic and anti-inflammatory activity of a novel series of 1,3,4-thiadiazole derivatives alone or combined with LD-RT with a single dose of 0.5 Gy. Initially, in vitro COX-1/COX-2 inhibition assays were performed, identifying the sulfonamide-containing compounds 5-10 as the most potent candidates, with IC50 values in the range of 0.32-0.37 µM and the highest selectivity indices. These compounds and celecoxib were subjected to in vivo examination after their safety was assessed through the acute toxicity test. Treatment with compounds 5-10 inhibited carrageenan-induced edema by nearly 47-56%, which was nearly equivalent to celecoxib. Compounds 7 and 8 and celecoxib showed an analgesic activity of 64.15%, 49.05%, and 84.90%, respectively, whereas compounds 5, 6, 9, and 10 did not show any analgesic activity unless combined with LD-RT. Ulcerogenic activity, histological paw examination, and docking studies were performed. Compounds 5-10 were nearly similar to celecoxib, showing normal histological features with no ulcerogenic activity.

Synthesis and antimicrobial evaluation of new halogenated 1,3-Thiazolidin-4-ones.

The ongoing prevalence of multidrug-resistant bacterial pathogens requires the development of new effective antibacterial agents. In this study, two series of halogenated 1,3-thiazolidin-4-ones were synthesized and characterized. All the synthesized thiazolidinone derivatives were evaluated for their antimicrobial activity. Biological screening of the tested compounds revealed the antibacterial activity of the chlorinated thiazolidinones 4a, 4b and 4c against Escherichia coli TolC-mutant, with MIC values of 16 µg/mL. A combination of a sub-inhibitory concentration of colistin (0.25 × MIC) with compounds 4a, 4b or 4c showed antibacterial activity against different Gram-negative bacteria (MICs = 4-16 µg/mL). Interestingly, compounds 4a, 4b and 4c were not cytotoxic to murine fibroblasts and Caco-2 cells. The chlorinated thiazolidinone derivative 16d demonstrated a bacteriostatic activity against a panel of pathogenic Gram-positive bacteria, including clinical isolates of methicillin and vancomycin-resistant Staphylococcus aureus, Listeria monocytogenes and multidrug-resistant Staphylococcus epidermidis (MICs = 8 - 64 µg/mL), with no cytotoxicity against both Caco-2 and L929 cells. Compound 16d was superior to vancomycin in disruption of the pre-formed MRSA biofilm. Furthermore, the three fluorinated thiazolidinone derivatives 26c, 30c and 33c showed a hindrance to hemolysin activity, without cytotoxicity against L929 cells.

Design and synthesis of novel pyridazinoquinazoline derivatives as potent VEGFR-2 inhibitors: In vitro and in vivo study.

Worldwide, Hepatocellular Carcinoma (HCC) endures to be a prominent cause of cancer death. Treatment of HCC follows multiple therapies which are not entirely applicable for treatment of all patients. HCC usually arises contextual to chronic liver diseases and is often discovered at later stages which makes treatment options more complex. The present study aimed at design, synthesis & evaluation of new pyridazinoquinazoline derivatives as potential nontoxic anti-hepatocellular carcinoma (HCC) agents, through inhibition of Vascular endothelial growth factor -2 (VEGFR-2). Novel Pyridazino[3, 4, 5-de]quinazoline derivatives (2-6) were designed & synthesized. Their structures were confirmed via spectral and microanalytical data. They were tested for their in vitro VEGFR-2 inhibition & anticancer activity against human liver cancer cell line (HEPG-2). Molecular docking was investigated into VEGFR-2 site. In vivo studies of VEGRF-2 inhibition and the anti-apoptotic effect of the new compounds were determined in liver of irradiated rats. Toxicity of synthesized compounds was also assessed. The results showed that compounds 3-6 have significant antitumor activity and proved to be non-toxic. The ethoxy aniline derivative 6, exhibited the highest activity both in vitro and in vivo compared to the reference drug used, sorafenib. Compound 6 could be considered a promising nontoxic anti HCC agent and this could be partially attributed to its VEGFR-2 inhibition. Future preclinical investigation would be carried out to confirm the specific and exact mechanism of action of these derivatives especially compound 6 as an effective pharmaceutical agent after full toxicological and pharmacological assessment.

Novel Anticancer Fused Pyrazole Derivatives as EGFR and VEGFR-2 Dual TK Inhibitors.

EGFR and VEGFR-2 represent promising targets for cancer treatment as they are very important in tumor development as well as in angiogenesis and metastasis. In this work, 6-amino-4-(2-bromophenyl)-3-methyl-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile 1 and (E)-4-(2-Bromobenzylidene)-5-methyl-2,4-dihydro-3H-pyrazol-3-one 11 were selected as starting materials to synthesize different fused pyrazole derivatives; dihydropyrano[2,3-c]pyrazole 1, 2, 7-9, and 15, pyrazolo[4',3':5,6]pyrano[2,3-d]pyrimidine 3-6, pyrazolo[3,4-d]pyrimidine 12 and 13, and pyrazolo[3,4-c]pyrazole 14 derivatives were synthesized to evaluate their anticancer activity against HEPG2 human cancer cell lines compared to erlotinib and sorafenib as reference drugs. Seven compounds 1, 2, 4, 8, 11, 12, and 15 showed nearly 10 fold higher activity than erlotinib (10.6 µM) with IC50 ranging from 0.31 to 0.71 µM. In vitro EGFR and VEGFR-2 inhibitory activity were performed for the synthesized compounds, and the results identified compound 3 as the most potent EGFR inhibitor (IC50 = 0.06 µM) and compound 9 as the most potent VEGFR-2 inhibitor (IC50 = 0.22 µM). Moreover, compounds 9 and 12 revealed potent dual EGFR and VEGFR-2 inhibition, and these results were supported by docking studies of these two compounds within the active sites of both enzymes.

Carbonic anhydrase inhibition with a series of novel benzenesulfonamide-triazole conjugates.

We report the synthesis and characterisation of a novel series of triazole benzenesulfonamide derivatives, which incorporate the general pharmacophore associated with carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. The synthesised compounds were tested in vitro against four human carbonic anhydrase (hCA, EC 4.2.1.1) isozymes, hCA I, hCA II, hCA IV and hCA IX. The obtained results showed that the tumour-associated hCA IX was the most sensitive to inhibition with the synthesised derivatives, with the triazolo-pyridine benzenesulfonamides 14, 16 and 17 being the most effective inhibitors. Some selected compounds were chosen for a single dose anti-proliferative activity testing against a panel of 57 human tumour cell lines and show some anti-proliferative activity ex vivo.

Novel thioureido-benzenesulfonamide derivatives with enaminone linker as potent anticancer, radiosensitizers and VEGFR2 inhibitors.

In this study, novel series of thioureido-benzenesulfonamide derivatives bearing an enaminone linker either meta or para oriented and having terminal linear or substituted aromatic or heteroaromatic ring system 5-16a,b were designed and synthesized based on the general pharmacophoric features of type II VEGFR2 inhibitors. Evaluation of the synthesized compounds against HEPG2 hepatocellular carcinoma cells in vitro identified compounds 5b, 6b and 10-13b as most active anticancer agents with IC50 equal to 0.12, 0.29, 0.58, 0.44, 0.42 and 0.66 µM, respectively. These compounds were evaluated for their ability to in vitro inhibit VEGFR2 kinase enzyme. The results demonstrated highly potent dose-related VEGFR2 inhibition with IC50 values in nanomolar range (33, 57, 210, 37, 37 and 220 nM, respectively). The radiosensitizing ability of the most promising compounds was studied which showed an increase in the cell killing effect of radiation after combination with the synthesized compounds which revealed lowered IC50 by nearly 50%. Molecular docking for the most potent compounds was performed to predict their possible binding mode within VEGFR2 active site and they showed binding affinity in a similar way to sorafenib.

Novel 1,2,4-triazole derivatives as antitumor agents against hepatocellular carcinoma.

Fifteen novel 1,2,3-triazole derivatives were prepared in series of synthetic steps starting from 4-amino-5-hydrazino-4H-1,2,4-triazole-3-thiol 1. The structures of the obtained compounds were verified through micoanalytical and spectral data. All the compounds were screened for their anticancer activity against liver human cancer cell lines (HEPG2) using Doxorubicin as standard. The most promising triazolothiadiazine derivative 12 was further tested for its degree of toxicity by estimating the median lethal dose (LD 50) and its antitumor activity through inhibiting the angiogenesis and progression of tumor against diethylnitrosamine (DENA)/CCl4 induced hepatocellular carcinoma (HCC) in rats. To elucidate its mechanism of action, the following parameters were determined including: vascular endothelial growth factor (VEGF) as a marker of angiogenesis; hepatic tyrosine kinase (HTK) as a marker for tumor growth; serum alpha fetoprotein (AFP) as a marker for hepatocarcinoma; aspartate and alanine aminotransferases (AST & ALT) as liver function test; malondialdehyde (MDA) and glutathione (GSH) as markers of antioxidant activity. Liver histopathological analysis was also evaluated. Carcinogenic rats showed drastic elevation in all investigated parameters accompanied by reduction in hepatic glutathione. Administration of compound 12 into rats after induction of experimental HCC, improved the biochemical changes induced by DENA/CCl4. These observations were supported by histopathological study of liver sections. It was concluded that triazolothiadiazine compound 12 could be promising anti HCC agent after more investigations on higher animals.

Anti-inflammatory, analgesic and COX-2 inhibitory activity of novel thiadiazoles in irradiated rats.

In this work, novel series of pyran, thiophene and thienopyrimidine derivatives based on 2-acetamide-thiadiazole scaffold were designed and synthesized for evaluation as selective COX-2 inhibitors in-vitro and investigated in-vivo as anti-inflammatory and analgesic agents against carrageenan-induced rat paw oedema model in irradiated rats, since its well-known that ionizing radiation plays an important role in exaggerating the inflammatory responses and in enhancing the release of inflammatory mediators in experimental animals. Toxicological studies were carried out to evaluate the ulcerogenic activity, acute toxicity and kidney and liver functions for the most potent compounds. In order to understand the binding mode of the synthesized compounds into the active site of COX-2, docking study was performed. Most of the tested compounds showed high inhibitory ability to COX-2. Among them, thiadiazole derivatives bearing thiophene and thienopyrimidine moieties were the most active derivatives, compound 26 showed extremely high selectivity index (SI) of >555.5µM which is nearly two folds better than celecoxib (>277.7µM), in addition to compounds 3, 16, 17, 21 and 26 with SI in the range of >308.6- >384.6µM. The 4-chlorothieno[2.3-d]pyrimidine derivative of thiadiazole 21 showed the highest anti-inflammatory activity in this study having 24.49% of oedema compared to celecoxib (18.61%) in addition to compounds 17 and 26 with 24.70 and 25.40% of oedema, respectively, while the thiadiazol-2-acetamide derivative 2 was the most potent analgesic compound with the highest nociceptive threshold (85.72g) very close to that of celecoxib (90.23g). These compounds showed high safety margin on gastric mucosa with no ulceration effect. Also the most active in-vivo anti-inflammatory compounds 17, 21 and 26 were found to be non-toxic in experimental rats with normal kidney and liver functions. Docking study of the synthesized compounds showed similar orientation as celecoxib within the active site of COX-2 enzyme and similar ability to emerge deeply in the additional pocket and binding with Arg513 and His90 the key amino acids responsible for selectivity.

Modulatory effects of new curcumin analogues on gamma-irradiation - Induced nephrotoxicity in rats.

In the present study, a new series of 2-amino-pyran-3-carbonitrile derivatives of curcumin 2-7 have been synthesized via one-pot simple and efficient protocol, involving the reaction of curcumin 1 with substituted-benzylidene-malononitrile to modify the 1,3-diketone moiety. The structures of the synthesized compounds 2-7 were elucidated by microanalytical and spectral data, which were found consistent with the assigned structures. The nephroprotective mechanism of these new curcumin analogues was evaluated on the post-gamma-irradiation (7 Gy) - induced nephrotoxicity in rats. Activation of Nrf2 by these curcumin analogues is responsible for the amendment of the antioxidant status, impairment of NF-κB signal, thus attenuate the nephrotoxicity induced post-γ-irradiation exposure. 4-Chloro-phenyl curcumin analogue 7 showed the most potent activity. In conclusion, the results of the present study demonstrate a promising role of these new curcumin analogues to attenuate the early symptoms of nephrotoxicity induced by γ-irradiation in rats via activation of Nrf2 gene expression. These new curcumin analogues need further toxicological investigations to assess their therapeutic index.

Radio-protective effect of some new curcumin analogues.

In the present study, novel symmetrical curcumin analogues (2-7) have been synthesized by substituting the phenolic OH of curcumin with different linkers providing additional keto-enol tautomerism, very essential for radioprotective activity. The structures of the synthesized compounds (2-7) were elucidated by elemental analysis, IR, (1)H-NMR, (13)C-NMR and mass spectral data and were found consistent with the assigned structures. The curative effect of these new compounds, against the oxidative stress due to exposure of rats to the whole body γ-irradiation (7Gy) was investigated. Gamma-irradiated rats exhibited elevations of ALT, AST activities, urea, creatinine, triglycerides, total cholesterol, malondialdehyde (MDA), nitric oxide (NO), Interleukin-6 (IL-6), Tumor Necrosis Factor-α (TNF-α) and Nuclear Factor-kappa B (NF-κB) levels. Contrariwise, the total protein, albumin, total calcium level, SOD, CAT, GSH-Px, GST activities and GSH content were decreased. Treatment of gamma-irradiated rats with the new curcumin analogues (2-7) showed significant amelioration in the in-vivo antioxidant status, liver and kidney functions, as well as the anti-inflammatory markers (IL-6, TNF-α and NF-κB). Inhibition of NF-κB could be responsible for the improvement of the antioxidant and anti-inflammatory status in gamma-irradiated animals, by down-regulation of IL-1ß and TNF-α level. In conclusion, the new curcumin analogues (2-7) exhibited post-protective effect on gamma-irradiation, by NF-κB inhibition.

Synthesis and biological evaluation of novel 2-phenylquinazoline-4-amine derivatives: identification of 6-phenyl-8H-benzo[g]quinazolino[4,3-b]quinazolin-8-one as a highly potent inducer of NAD(P)H quinone oxidoreductase 1.

A novel series of quinazoline compounds (2-14) incorporating biologically active heterocyclic moieties were designed and synthesized. The structure of the newly synthesized compounds was recognized on the basis of elemental analyses, IR, 1H-NMR, 13C-NMR and mass spectral data. All compounds were evaluated for their ability to induce the cytoprotective enzyme NAD(P)H:quinone oxidoreductase 1 (NQO1) using a quantitative bioassay and a docking study was performed in the Kelch domain of Keap1 obtained from the Protein Data Bank (PDB ID: 4IQK) to explore the ability of the synthesized compounds to block the Nrf2-binding site of Keap1. All of the synthesized compounds showed concentration-dependent inducer activity with potencies in the low- or sub-micromolar range. Compound 12 was the most potent inducer in this new series, with a concentration that doubles the specific activity of NQO1 (CD value) of 70 nM. The identification of this compound offers a new chemical scaffold for future development of highly potent inducers.

In-Vitro Anticancer Evaluation of Some Novel Thioureido-Benzensulfonamide Derivatives.

A novel series of sulfonamide derivatives (14 compounds) bearing thiourea moieties were efficiently synthesized and evaluated for their possible in vitro anticancer activity against four human tumor cell lines. The results indicated that compound 6 was the most potent, showing effectiveness on all the tested cell lines. Compounds 7 and 10 also showed promising results.

Design, Synthesis and Anticancer Evaluation of Novel Quinazoline-Sulfonamide Hybrids.

By combining the structural features of quinazoline and sulfonamides, novel hybrid compounds 2-21 were synthesized using a simple and convenient method. Evaluation of these compounds against different cell lines identified compounds 7 and 17 as most active anticancer agents as they showed effectiveness on the four tested cell lines. The anticancer screening results of the tested compounds provides an encouraging framework that could lead to the development of potent new anticancer agents.

In-Vitro Anticancer Evaluation and Docking Study of Novel Benzo[g] Quinazoline-sulfonamide Derivatives.

BACKGROUND: Quinazoline and sulfonamide derivatives are considered to be important classes of drugs due to their wide range of biological activities especially anticancer. METHODS: A novel series of sulfonamides incorporating benzo[g] quinazolinemoieties 2-19 and sulfonyl containing benzo[g] quinazolinemoieties 20, 21 were designed and synthesized starting from 4- chlorobenzo[g] quinazoline 1. In-vitro screening as anticancer agents was done for the synthesized compounds. Molecular docking study was also performed to explore the binding interactions of the synthesized compounds within the active site of carbonic anhydrase IX (CA IX), which most commonly expressed in some types of cancer cells. CONCLUSION: The results indicated that the most potent compounds were 2 and 7 showing effectiveness on more than one cell line.