Novel dihydropyridine thioglycosides and their corresponding dehydrogenated forms as potent anti-hepatocellular carcinoma agents

A novel method for preparation of a new class of dihydropyridine thioglycosides and their corresponding dehydrogenated forms, via reaction of piperidinium salts of dihydropyridinethiones with 2,3,4,6-tetra-O-acetyl-α-D-gluco- and galactopyranosyl bromides has been studied. The evaluation of antiproliferative activity against HepG-2 cell lines (liver carcinoma cell lines) of the dihydropyridine thioglycosides and pyridine thioglycosides revealed that many of the thioglycosides have interesting antitumor activities specifically 5c, 5g, 5l, 5o, 5p, 7a, 7i, 7p, 8b, 8f, 8s, and 8v.     

Design,synthesis, molecular docking and anti-hepatocellular carcinoma evaluation of novel acyclic pyridine thioglycosides

A novel series of acyclic pyridine thioglycosides has been synthesized. Evaluation of the anti proliferative activity of these compounds against HEPG-2 cell lines (liver carcinoma cell lines) shows that most of the compounds have high anti-tumor activities especially 6b, 6c, 7b and 7c. Furthermore, in the modeling study, these compounds showed that they have high binding affinity with thymidylate synthase dihydrofolate reductase (TS-DHFR).     

First novel synthesis of triazole thioglycosides as ribavirin analogues

This study reports a novel and efficient method for the synthesis of the first reported novel class of triazole thioglycosides. These series of compounds were designed through the reaction of potassium cyanocarbonimidodithioate 2 with hydrazine derivatives 3a-d in EtOH at room temperature to give the corresponding potassium 5-amino-1H-1,2,4-triazole-3-thiolates 4a-d. The latter compounds were treated with tetra-O-acetyl-α-D-glucopyranosyl bromide 6a and tetra-O-acetyl-α-D-galactopyranosyl bromide 6b in DMF at room temperature to give in high yields the corresponding triazole thioglycosides 7a-h. Treatment of triazole salts 4a–d with hydrochloric acid afforded the corresponding 3-mercaptotriazoles 5a-d. Compounds 5a-d were then reacted with bromoperacetylated sugars 6a,b in sodium hydride-DMF at ambient temperature to afford the thioglycosyl compounds 7a-h. Ammonolysis of the triazole thioglycosides 7a-h afforded the corresponding free thioglycosides 8a-h. The scope and limitation of the method is demonstrated. The structure of the reaction products was confirmed on the basis of their elemental analysis and spectral data (IR, ¹H NMR, MS and ¹³C NMR).     

Synthesis of the first novel pyrazole thioglycosides as deaza ribavirin analogues

This study reports a novel and efficient method for the synthesis of the first reported novel class of thiopyrazoles and their corresponding thioglycosides. These series of compounds were designed through the reaction of hydrazine derivatives with sodium dithiolate salt 2 in EtOH at ambient temperature to give the corresponding sodium 5-amino-4-cyano-1H-pyrazole-3-thiolates 4a-d. The latter compounds were treated with α-acetobromoglucose 6a and α-acetobromogalactose 6b in DMF at ambient temperature to give in an excellent yields the corresponding pyrazole S-glycosides 7a-h. Ammonolysis of the pyrazole thioglycosides 7a-h afforded the corresponding free thioglycosides 8a-h.     

6-Bromoquinazoline Derivatives as Potent Anticancer Agents: Synthesis,Cytotoxic Evaluation,and Computational Studies

A series of 6-bromoquinazoline derivatives ( 5a – j ) were synthesized. Cytotoxic effectiveness of compounds was done against two cancerous cell lines (MCF-7 and SW480) by standard MTT method. Fortunately, all of the compounds showed desirable activity in reducing the viability of the studied cancerous cell lines with IC₅₀ value in the range of 0.53–46.6 μM. Compound 5b with a fluoro substitution at meta position of the phenyl moiety showed stronger activity than cisplatin with IC₅₀=0.53–1.95 μM. Studies on the hit compound ( 5b ) through apoptosis assay illustrated that it could induce apoptosis in MCF-7 cell lines in dose dependent manner. Molecular docking study was done to investigate the detailed binding modes and interactions with EGFR as a plausible mechanism. The drug- likeness was predicted. To survey the reactivity of compounds, DFT calculation was performed. Taken together, 6-bromoquinazoline derivatives, especially 5b can be considered as hit compounds to rational drug designing as antiproliferative agents.     

Synthesis and anticancer activity of new [(Indolyl)pyrazolyl]-1,3,4-oxadiazole thioglycosides and acyclic nucleoside analogs

New [(Indolyl)pyrazolyl]-1,3,4-oxadiazole compounds and their derived thioglycosides as well as the corresponding sugar hydrazones were synthesized. The acyclo C-nucleoside analogs of the oxadiazoline base system were also prepared by reaction of acid hydrazides with aldehydo sugars followed by one pot process encompassing acetylation and cyclization of the synthesized hydrazones. The anticancer activity of the newly synthesized compounds was studied against colorectal carcinoma (HCT116), breast adenocarcinoma (MCF7) and prostate cancer (PC3) human tumor cell lines and a number of compounds showed moderate to high activities.     

Novel oxindole/benzofuran hybrids as potential dual CDK2/GSK-3β inhibitors targeting breast cancer: design,synthesis, biological evaluation,and in silico studies

The serine/threonine protein kinases CDK2 and GSK-3β are key oncotargets in breast cancer cell lines, therefore, in the present study three series of oxindole-benzofuran hybrids were designed and synthesised as dual CDK2/GSK-3β inhibitors targeting breast cancer (5a–g, 7a–h, and 13a–b). The N¹-unsubstituted oxindole derivatives, series 5, showed moderate to potent activity on both MCF-7 and T-47D breast cancer cell lines. Compounds 5d–f showed the most potent cytotoxic activity with IC₅₀ of 3.41, 3.45 and 2.27 μM, respectively, on MCF-7 and of 3.82, 4.53 and 7.80 μM, respectively, on T-47D cell lines, in comparison to the used reference standard (staurosporine) IC₅₀ of 4.81 and 4.34 μM, respectively. On the other hand, the N¹-substituted oxindole derivatives, series 7 and 13, showed moderate to weak cytotoxic activity on both breast cancer cell lines. CDK2 and GSK-3β enzyme inhibition assay of series 5 revealed that compounds 5d and 5f are showing potent dual CDK2/GSK-3β inhibitory activity with IC₅₀ of 37.77 and 52.75 nM, respectively, on CDK2 and 32.09 and 40.13 nM, respectively, on GSK-3β. The most potent compounds 5d–f caused cell cycle arrest in the G2/M phase in MCF-7 cells inducing cell apoptosis because of the CDK2/GSK-3β inhibition. Molecular docking studies showed that the newly synthesised N¹-unsubstituted oxindole hybrids have comparable binding patterns in both CDK2 and GSK-3β. The oxindole ring is accommodated in the hinge region interacting through hydrogen bonding with the backbone CO and NH of the key amino acids Glu81 and Leu83, respectively, in CDK2 and Asp133 and Val135, respectively, in GSK-3β. Whereas, in series 7 and 13, the N¹-substitutions on the oxindole nucleus hinder the compounds from achieving these key interactions with hinge region amino acids what rationalises their moderate to low anti-proliferative activity.     

Novel synthesis of new pyrazole thioglycosides as pyrazomycin analogues

This study reports a novel method for the synthesis of a new class of pyrazole thioglycosides 7a-h as pyrazomycin analogues. These series of compounds were designed through the reaction of sodium 2-cyano-3-oxo-3-(4-substitutedphenylamino)prop-1-ene-1,1-bis(thiolate) salts 2 with phenyl hydrazine in ethanol at room temperature to give the corresponding sodium 5-amino-4-(substitutedphenylcarbamoyl)-1-phenyl-1H-pyrazole-3-thiolates 3a-d. The latter compounds were treated with tetra-acetylated glycosyl bromides 4a,b in DMF at ambient temperature to give the corresponding pyrazole thioglycosides 6a-h. Treatment of pyrazole salts 3a–d with hydrochloric acid at room temperature afforded the corresponding 3-mercaptopyrazole derivatives 5. The latter compounds were treated with tetra-acetylated glycosyl bromides 4 in sodium hydride-DMF to tolerate the S-glycosyl 6a-h compounds. Ammonolysis of the latters afforded the corresponding free thioglycosides 7a-h. The structures of the reaction products were elucidated based on spectral data and elemental analysis.     

A facile synthesis of novel pyrazolopyrimidine thioglycosides as purine thioglycoside analogues

The easy, convenient and high yielding preparation of new thioglycosides incorporating mercaptopyrazolo[1,5-a]pyrimidine moieties from readily accessible starting materials has been reported. The main step of this protocol is the formation of 7-mercaptopyrazolo[1,5-a]pyrimidine-6-carbonitrile derivatives 4a-d by condensation of sodium 2-cyano-3-ethoxy-3-oxoprop-1-ene-1,1-bis(thiolate) 1 with 4-(aryldiazenyl)-1H-pyrazole-3,5-diamines 3a-d to form target compounds 4a-d, which coupled with tetra-O-acetyl-α-D-glycopyranosyl bromides 5a,b in the presence of basic medium to provide the corresponding product purine thioglycoside analogs 6a-h. Ammonolysis of the latter compounds 6a-d at ambient temperature for 10 minutes, led to the free glycoside derivatives 7a-h, which were obtained in approximately quantitative yields. Their structures were created based on the spectroscopic and elemental data.     

1,2,3‐Triazole Tagged 3H‐Pyrano[2,3‐d]pyrimidine‐6‐carboxylate Derivatives: Synthesis,in Vitro Cytotoxicity,Molecular Docking and DNA Interaction Studies

A series of novel ethyl 2,7‐dimethyl‐4‐oxo‐3‐[(1‐phenyl‐1H‐1,2,3‐triazol‐4‐yl)methyl]‐4,5‐dihydro‐3H‐pyrano[2,3‐d]pyrimidine‐6‐carboxylate derivatives 7a – 7m were efficiently synthesized employing click chemistry approach and evaluated for in vitro cytotoxic activity against four tumor cell lines: A549 (human lung adenocarcinoma cell line), HepG2 (human hematoma), MCF‐7 (human breast adenocarcinoma), and SKOV3 (human ovarian carcinoma cell line). Among the compounds tested, the compounds 7a , 7b , 7f , 7l , and 7m have shown potential and selective activity against human lung adenocarcinoma cell line (A549) with IC₅₀ ranging from 0.69 to 6.74 μm . Molecular docking studies revealed that the compounds 7a , 7b , 7f , 7l , and 7m are potent inhibitors of human DNA topoisomerase‐II and also showed compliance with stranded parameters of drug likeness. The calculated binding constants, k_b, from UV/VIS absorptional binding studies of 7a and 7l with CT‐DNA were 10.77 × 10⁴, 6.48 × 10⁴, respectively. Viscosity measurements revealed that the binding could be surface binding mainly due to groove binding. DNA cleavage study showed that 7a and 7l have the potential to cleave pBR322 plasmid DNA without any external agents.     

Design,synthesis and evaluation of carbazole derivatives as potential antimicrobial agents

Five series of novel carbazole derivatives containing an aminoguanidine, dihydrotriazine, thiosemicarbazide, semicarbazide or isonicotinic moiety were designed, synthesised and evaluated for their antimicrobial activities. Most of the compounds exhibited potent inhibitory activities towards different bacterial strains (including one multidrug-resistant clinical isolate) and one fungal strain with minimum inhibitory concentrations (MICs) between 0.5 and 16 µg/ml. Compounds 8f and 9d showed the most potent inhibitory activities (MICs of 0.5–2 µg/ml). Furthermore, compounds 8b, 8d, 8f, 8k, 9b and 9e with antimicrobial activities were not cytotoxic to human gastric cancer cell lines (SGC-7901 and AGS) or a normal human liver cell line (L-02). Structure–activity relationship analyses and docking studies implicated the dihydrotriazine group in increasing the antimicrobial potency and reducing the toxicity of the carbazole compounds. In vitro enzyme activity assays suggested that compound 8f binding to dihydrofolate reductase might account for the antimicrobial effect.     

Synthesis and biological evaluation of purine-pyrazole hybrids incorporating thiazole,thiazolidinone or rhodanine moiety as 15-LOX inhibitors endowed with anticancer and antioxidant potential

Novel purine-pyrazole hybrids combining thiazoles, thiazolidinones and rhodanines, were designed and tested as 15-LOX inhibitors, potential anticancer and antioxidant agents. All tested compounds were found to be potent 15-LOX inhibitors with IC₅₀ ranging from 1.76 to 6.12 µM. The prepared compounds were evaluated in vitro against five cancer cell lines: A549 (lung), Caco-2 (colon), PC3 (prostate), MCF-7 (breast) and HepG-2 (liver). Compounds 7b and 8b displayed broad spectrum anticancer activity against the five tested cell lines (IC₅₀ = 18.5–95.39 µM). While, compound 7h demonstrated moderate anticancer activity against lung A549 and colon Caco-2 cell lines. Antioxidant screening revealed that six compounds (5a, 5b, 6b, 7b, 7h and 8b) with IC₅₀ ranging from 0.93 to 14.43 µg/ml were found to be more potent scavengers of 2,2- diphenyl-1-picrylhydrazyl (DPPH) than the reference ascorbic acid with IC₅₀ value of 15.34 µg/ml. Compounds 7b, 7h and 8b, when evaluated for their antioxidant activity, where found to be potent DPPH scavengers. Moreover, compound 7b displayed twice the potency of ascorbic acid as NO scavenger. Docking study was performed to elucidate the possible binding mode of the most active compounds with the active site of 15-LOX enzyme. Collectively, the purine-pyrazole hybrids having thiazoline or thizolidinone moieties (7b, 7h and 8b) constitute a promising scaffold in designing more potent 15-LOX inhibitors with anticancer and antioxidant potential.     

Synthesis,antitumor activity and molecular docking study of some novel 3-benzyl-4(3H)quinazolinone analogues

A novel series of 3-benzyl-substituted-4(3H)-quinazolinones were designed, synthesized and evaluated for their in vitro antitumor activity. The results of this study demonstrated that 2-(3-benzyl-6-methyl-4-oxo-3,4-dihydroquinazolin-2-ylthio)-N-(3,4,5-trimethoxyphenyl)acetamide, 2-(3-benzyl-6,7-dimethoxy-4-oxo-3,4-dihydroquinazolin-2-ylthio)-N-(3,4,5-trimethoxyphenyl)acetamide and 3-(3-benzyl-6-methyl-4-oxo-3,4-dihydroquinazolin-2-ylthio)-N-(3,4,5-trimethoxyphenyl)-propanamide have shown amazing broad spectrum antitumor activity with mean GI₅₀ (10.47, 7.24 and 14.12?µM. respectively), and are nearly 1.5–3.0-fold more potent compared with the positive control 5-FU with mean GI₅₀, 22.60?µM. On the other hand, compounds 6 and 10 yielded selective activities toward CNS, renal and breast cancer cell lines, whereas compound 9 showed selective activities towards leukemia cell lines. Molecular docking methodology was performed for compounds 7 and 8 into ATP binding site of EGFR-TK which showed similar binding mode to erlotinib, while compound 11 into ATP binding site of B-RAF kinase inhibited the growth of melanoma cell lines through inhibition of B-RAF kinase, similar to PLX4032.     

Design,synthesis and molecular docking of novel diarylcyclohexenone and diarylindazole derivatives as tubulin polymerization inhibitors

New target compounds were designed as inhibitors of tubulin polymerization relying on using two types of ring B models (cyclohexenone and indazole) to replace the central ring in colchicine. Different functional groups (R¹) were attached to manipulate their physicochemical properties and/or their biological activity. The designed compounds were assessed for their antitumor activity on HCT-116 and MCF-7 cancer cell lines. Compounds 4b, 5e and 5f exhibited comparable or higher potency than colchicine against colon HCT-116 and MCF-7 tumor cells. The mechanism of the antitumor activity was investigated through evaluating the tubulin inhibition potential of the active compounds. Compounds 4b, 5e and 5f showed percentage inhibition of tubulin in both cell line homogenates ranging from 79.72% to 89.31%. Cell cycle analysis of compounds 4b, 5e and 5f revealed cell cycle arrest at G₂/M phase. Molecular docking revealed the binding mode of these new compounds into the colchicine binding site of tubulin.     

A First Microwave-Assisted Synthesis of a New Class of Purine and Guanine Thioglycoside Analogs

A first microwave-assisted synthesis of a new class of novel purine thioglycoside analogs from readily available starting materials has been described. The key step of this protocol is the formation of sodium pyrazolo[1,5-a]pyrimidine-7-thiolate and 7-mercaptopyrazolo[1,5-a]pyrimidine derivatives via condensation of 5-amino-1H-pyrazoles with sodium 2,2-dicyanoethene-1,1-bis(thiolate) salts or 2-(dimercaptomethylene)malononitrile, respectively, under microwave irradiation, followed by coupling with halo sugars to give the corresponding purine thioglycoside analogs. The obtained purines and purines thioglycosides derivatives were evaluated in vitro against lung (A549), colon (HCT116), liver (HEPG2), and prostate (PC3) cancer cell lines. Some of these compounds (5b, 5d, 5f, and 9a–d) exhibited little potency toward the four cell lines. On the other hand, compound 5a elicited higher cytotoxicity on both prostate (PC3) and colon (HCT116), respectively, while it was found moderate on lung (A549), and inactive on liver (HEPG2). Moreover, compound 5c was found moderate with LC₅₀ values 52.0–88.9 μM for almost all the cell lines.     

Design,synthesis, and in vitro anti-hepatocellular carcinoma of novel thymine thioglycoside analogs as new antimetabolic agents

A first reported direct method for preparation of thymine thioglycoside analogs utilizing novel pyrimidine-2(1H)-thiones and α-bromoglucose or α-bromogalactose tetraacetate as starting components is described. The synthetic potential of the method is demonstrated. The evaluation of antiproliferative activity against HepG-2 cell lines (Liver carcinoma cell lines) shows that most of the compounds have high antitumor activities especially 6b, 6e, 11b, and 12b. Moreover, molecular modelings of these compounds reveal that they have high binding affinity through hydrogen bond interaction with the binding pocket of thymidylate synthase dihydrofolate reductase (TS-DHFR).     

Discovery of new VEGFR-2 inhibitors based on bis([1, 2, 4]triazolo)[4,3-a:3',4'-c]quinoxaline derivatives as anticancer agents and apoptosis inducers

Herein, a new wave of bis([1, 2, 4]triazolo)[4,3-a:3'',4''-c]quinoxaline derivatives have been successfully designed and synthesised. The synthesised derivatives were biologically investigated for their cytotoxic activities against HepG2 and MCF-7. Also, the tested compounds were further examined in vitro for their VEGFR-2 inhibitory activity. The most promising derivative 23j was further investigated for its apoptotic behaviour in HepG2 cell lines using flow cytometric and western-plot analyses. Additional in-silico studies were performed to predict how the synthesised compounds can bind to VEGFR-2 and to determine the drug-likeness profiling of these derivatives. The results revealed that compounds 23a, 23i, 23j, 23l, and 23n displayed the highest antiproliferative activities against the two cell lines with IC₅₀ values ranging from 6.4 to 19.4 µM. Furthermore, compounds 23a, 23d, 23h, 23i, 23j, 23l, 23 m, and 23n showed the highest VEGFR-2 inhibitory activities with IC₅₀ values ranging from 3.7 to 11.8 nM, comparing to sorafenib (IC₅₀ = 3.12 nM). Moreover, compound 23j arrested the HepG2 cell growth at the G2/M phase and induced apoptosis by 40.12% compared to the control cells (7.07%). As well, such compound showed a significant increase in the level of caspase-3 (1.36-fold), caspase-9 (2.80-fold), and BAX (1.65-fold), and exhibited a significant decrease in Bcl-2 level (2.63-fold).     

Molecular modelling design,synthesis and cytotoxic evaluation of certain substituted 2-(3,4,5-triacetoxybenzoylamino)benzo[d]thiazole and 2-(galloylamino)benzo[d]thiazole derivatives having potential topoisomerase-I inhibitory activity

New 2-(3,4,5-triacetoxybenzoylamino)benzothiazoles (4a~5f) and 2-(galloylamino)benzothiazoles (6a~7f), were designed as topoisomerase-I inhibitors. Compare/fit studies between these molecules and the generated topoisomerase-I inhibitors hypothesis revealed that 4a~5f have higher fitting values than (6a~7f). Also, docking of 4a~7f with the topoisomerase-I enzyme prioritized the higher activity of (4a~5f) than (6a~7f). These molecules were synthesized and biologically evaluated for their in vitro cytotoxic activity against Hela and MCF7 human cancer cell lines in comparison to Camptothecin (topo-I inhibitor) and doxorubicin (topo-II inhibitors) as reference drugs. Such screening revealed that compounds 4d, 4e, 4h, 5b, 5c and 5e have comparable higher cytotoxic activity in both cultures than these reference drugs. The highest active molecule was 5f that gave 1.5 folds higher cytotoxic activity against Hela cell cultures and 1.9 folds higher activity against MCF7 cell lines than doxorubicin and 1.6 folds and 2.2 folds higher activity towards the two respective cultures than Camptothecin.     

Furo[2,3-d]pyrimidines as Mackinazolinone/Isaindigotone Analogs: Synthesis,Modification, Antitumor Activity,and Molecular Docking Study

The chemical transformation of the tricyclic furo[2,3-d]pyrimidines was performed under isosteric and scaffold-hopping strategies focusing on the synthesis of its arylidene and imine-containing derivatives. Naturally-occurring alkaloids mackinazolinone and isaindigotone were as templates of target heterocycles. Synthesized compounds evaluated for their antitumor activity on human cancer cervical HeLa, breast MCF-7, and colon HT-29 cell lines. Four compounds: 8c , 8e , 10b , and 10c demonstrated potency against HeLa and HT-29 cell lines, and IC₅₀ values were between 7.37–13.72 μM, respectively. The molecular docking results showed that compounds 8c and 10b had good binding and high matching with the target EGFR protein.     

Synthesis and In Vitro Antitumor Activity of New Substituted Thiopyrimidine Acyclic Nucleosides and Their Thioglycoside Analogs

Some new thiopyrimidine acyclic nucleosides and thioglycoside derivatives 3a-c, 4a-c, 6a,b, and 7a,b were synthesized. The cytotoxicity and antitumor evaluation of all prepared compounds have been tested in vitro against Ehrlich's ascites carcinoma cell line and their activity against glutathione peroxidase and catalase were reported. The role of the prepared compounds as free radical regulators and the therapeutic antitumor effect of a balanced generation of free radicals are discussed. Compounds 2, 3b, 3c, 4a, and 4c inhibited significantly in a dose dependent manner the growth of Ehrlich ascites carcinoma cells while the other compounds did not show any antitumor activity even at higher concentrations.