Synthesis, In Vitro Evaluation and Molecular Docking Studies of Novel Thiophenyl Thiazolyl-Pyridine Hybrids as Potential Anticancer Agents.

Many literature reports revealed the anticancer activity of pyridine and thiazole derivatives, especially in lung cancer. Therefore, a new series of thiazolyl pyridines linked with thiophene moiety via hydrazone group was prepared by one-pot multi-component reaction of (E)-1-(4-methyl-2-(2-(1-(thiophen-2-yl)ethylidene)hydrazinyl)thiazol-5-yl)ethanone with benzaldehyde derivatives and malononitrile in a good yield. Then, compound 5 and the thiazolyl pyridines were investigated for their in vitro anticancer activity against lung cancer (A549) cell line using MTT assay compared to doxorubicin as a reference drug. The structure of all the newly synthesized compounds was established based on spectroscopic data and elemental analyses. For better insight to investigate their mechanism of action on A549 cell line, docking studies were performed, targeting epidermal growth factor receptor (EGFR) tyrosine kinase. The results obtained revealed that the tested compounds displayed excellent anticancer activities against lung cancer cell line except 8c and 8f compared to reference drug. Based on the data obtained, it can be inferred that the novel compounds, as well as their key intermediate, compound 5, demonstrated potent anticancer activity against lung carcinoma by inhibiting EGFR.

Synthesis of Novel Bis-pyrazole Derivatives as Antimicrobial Agents.

BACKGROUND: Bis-heterocycles especially those containing pyrazole moiety display much better antibacterial activity than mono heterocycles. OBJECTIVE: Herein, we synthesised a series of new bis-pyrazoles and investigated their antimicrobial agents. METHODS: A novel series of bis-pyrazole derivatives have been synthesized in good yield by coupling reaction of cyanoacetic acid {4-[(2-cyano-acetyl)-hydrazonomethyl]-benzylidene}-hydrazide with a number of diazonium salts of aromatic amines in DMF in the presence of NaOH. Refluxing of the produced hydrazones with hydrazine-hydrate in ethanolic solution afforded the respective bis-pyrazoles. On the other hand, the reaction of bis(cyanoacetic acid hydrazide) derivative with a diversity of hydrazonoyl chlorides in dioxane under reflux gave bis-pyrazoles. RESULTS: The structures of all the products were discussed and assured from all possible spectral data as well as for the elemental analysis. In addition, the results of the antimicrobial activity examination of selected derivatives revealed a high strength of some tested compounds compared to standard bactericides and fungicides utilized. Molecular docking of the newly synthesized compounds into the Enoyl ACP reductase active site supported the in vitro antimicrobial activity. All the tested compounds could fit in the enzyme binding pocket with significant binding affinities (-7.040 to -9.141 Kcal/mol). CONCLUSION: The good results of the antimicrobial examination of the newly synthesized bis-pyrazoles comprise the considerable evidence of the importance of bis-heterocyclic compounds which encourages us to continue designing and synthesising a novel series with potent biological activity in the future.

Synthesis, Cytotoxicity Evaluation, Molecular Docking and Utility of Novel Chalcones as Precursors for Heterocycles Incorporating Pyrazole Moiety.

BACKGROUND: Chalcones, 2-pyrazolines and thiazoles have been reported to possess various pharmacological activities. OBJECTIVE: Synthesis of new chalcones and utilizing them as a building block for constructing a series of thiazole derivatives and evaluating some of them as anticancer agents. METHOD: The new compounds were synthesized via stirring at room temperature or thermal heating. Cytotoxic evaluation of the new synthesized compounds was tested using the method of Skehan et al. Moreover, the computational studies were performed using MOE 2014.09 software. RESULT: A series of new chalcones were prepared by the reaction of ethyl 3-acetyl-1-aryl-5-methyl- 1H-pyrazole-4-carboxylate with a number of substituted benzaldehydes. One of these chalcones was used as a building block for constructing a pyrazoline ring via its reaction with thiosemicarbazide. The produced carbothioamide derivative was used for the preparation of two series of thiazole derivatives by its reaction with a number of hydrazonoyl chlorides. Moreover, reaction of 3- acetylpyrazole thiosemicarbazone derivative with a number of N-aryl-2-oxopropane hydrazonoyl chlorides afforded 5-arylazothiazole derivatives. The assigned structures for all the newly synthesized compounds were confirmed on the basis of elemental analyses and spectral data. Some of the newly synthesized chalcones and thiazoles were tested for their cytotoxicity against human colon carcinoma cell line (HCT-116) and the molecular docking was carried out on the most active compound 3f. CONCLUSION: The results of the anticancer activity revealed that compounds 3f, 3e, 3c and 3b have promising activities compared with the standard drug Doxorubicin. Moreover, the computational studies confirm the results of biological activity. Also, the ADME profile study showed that compound 3f can be considered as a promising drug by conducting good pharmacokinetic and medicinal chemistry tests.

Anti-inflammatory, Analgesic and Anti-ulcerogenic Activities of Novel bis-thiadiazoles, bis-thiazoles and bis-formazanes.

BACKGROUND: Indane-1,3-dione, thiazole, bis-thiazole and thiadiazoles rings are very interested moieties in anti-inflammatory and analgesic drugs. OBJECTIVE: The goal of this work is to synthesize new derivatives of bis-thiazoles and bis-1,3,4- thiadiazoles for the investigation of their anti-inflammatory, anti-ulcerogenic and analgesic activities. METHODS: 1,1'-(1,2-phenylene)bis(3-phenylthiourea) (1) reacts with a number of N-aryl arenecarbohydrazonoyl chlorides 2 to give a series of new bis-1,3,4-thiadiazoles 4. Also, reaction of bisthiosemicarbazone of 1,3-indanedione 6 with another type of hydrazonoyl halides namely, N-aryl-2- oxapropanehydrazonoyl chlorides 7 and ethyl-(N-arylhydrazono)chloroacetate 8 in dioxane under reflux in the presence of triethylamine give the respective bis-thiazole derivatives 9 and 10, respectively. The products 9 and 10 can exist in five and seven tautomeric forms for each one. Their actual tautomeric forms were deduced based on electronic absorption data (UV / Vis spectra). Moreover, a series of novel bis-formazans 12 and 13 have been synthesized by reaction of 1,3-dihydrazono-2,3- dihydro-1H-indene (11) with both hydrazonoyl chlorides 7 and 8. RESULTS: The structure of all the novel products was deduced by elemental analysis and spectral data. In addition, the biological activity of the newly synthesized compounds was evaluated and the results obtained indicate their potency as anti-inflammatory, anti-ulcerogenic and analgesic agents. CONCLUSION: In this context, we synthesize new derivatives of bis-thiazoles and bis-1,3,4-thiadiazoles as anti-inflammatory, anti-ulcerogenic and analgesic agents.

New and efficient approach for synthesis of novel bioactive [1,3,4]thiadiazoles incorporated with 1,3-thiazole moiety.

A series of novel 1,3,4-thiadiazoles incorporated with thiazole moiety was synthesized by reaction of 5-acetyl-2-benzoylimino-3-phenyl-1,3,4-thiadiazole thiosemicarbazone 2 with each of N-phenyl 2-oxo-propanehydrazonoyl chloride 3 and ethyl (N-aryl-hydrazono) chloroacetate 5 in dioxane in basic medium. Also, another series of 1,3,4-thiadiazole incorporated with thiazole moiety was prepared by reaction of 5-acetyl-2-benzoylimino-3-phenyl-1,3,4-thiadiazole thiocarbohydrazone with each of hydrazonoyl chlorides 3, 5 and 18 under the same reaction conditions. The mechanisms of the studied reactions were discussed and the assigned structure for each of the new products was identified via elemental and spectral data and by alternative method whenever possible. Moreover, the antimicrobial activity for some selected products was screened, and the results obtained exploring the high potency of some of the tested compounds compared with the employed standard bactericides and fungicide.

A new one-pot synthesis of novel hetarylazo-heterocyclic colorants and study of their solvatochromic properties.

A simple synthetic strategy for synthesis of new series of hetarylazo-heterocycles is described. The effects of solvent on their electronic absorption spectra were analyzed using Kamlet-Taft equation. The results of fitting coefficients indicated that the solvatochromism of the studied compounds is mainly due to the solvent polarity rather than the solvent basicity and acidity.

Synthesis and antimicrobial activity of some new 1,3,4-thiadiazole derivatives.

New series of 1,3,4-thiadiazoles have been prepared via reaction of 1,3,4-thiadiazolenaminones 1 with N-phenyl 2-oxopropanehydrazonoyl chloride (2) in dioxane in the presence of triethylamine. Also, some new heterocycles incorporating 1,3,4-thiadiazole ring were obtained by reaction of 1,3,4-thiadiazolenaminones 1 with nitrogen-nucleophiles like hydrazine hydrate, 3-amino-1,2,4-triazole and 2-aminobenzimidazole. The structure of the new products was established based on elemental and spectral analysis. The relation between the structure of the products and their activity towards some microorganisms was studied and promising results were obtained.

Synthesis and evaluation of the anti-microbial activity of new heterocycles containing the 1,3,4-thiadiazole moiety.

A new series of thiadiazole-enaminones 4 were synthesized via reactions of 5-acetyl-1,3,4-thiadiazoles 3 with dimethylformamide-dimethylacetal (DMF-DMA). The simple phenyl substituted thiadiazole-enaminone 4f was used as a synthetic precursor for the preparation of a wide variety of new heterocyclic compounds, including the 5-substituted-1,3,4-thiadiazole derivatives 5, 6, 11, 12 and 13, which were obtained via reactions of 4f with nitrogen nucleophiles. Also, reactions of enaminone 4f with carbon nucleophiles afforded the respective 1,3,4-thiadiazoles 8a-d. In addition, the results of the antimicrobial activities of thiadiazole-enaminones 4 and their precursors 2 and 3 indicate that some members of this series display promising activities against all tested microorganisms.

A Facile One-pot Synthesis and Antimicrobial Activity of Pyrido [2,3-d][1,2,4]triazolo[4,3-a]pyrimidin-5-ones.

A series of pyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidin-5-ones (8) has been synthesised via reaction of 5-substituted-2-thioxo-2,3-dihydro-1H-pyrido[2,3-d]pyrimidin-4-one (3) or its methylthio derivative 4 with hydrazonoyl chlorides 5. Alternative syntheses of products 8 were carried out either by reaction of enaminone 1 with 7-amino-1,3-disubstituted[1,2,4]triazolo[4,3-a]pyrimidin-5-one (10) or via the Japp-Klingemann reaction of compound 13. Both conventional thermal and microwave irradiation techniques were used for synthesis of the target products 8 and a comparative study of these techniques using triethylamine or chitosan, as basic catalysts, was carried out. The mechanisms of the reactions under investigation are discussed. In addition, the antimicrobial activity of the newly synthesized products was evaluated.

New pyrazoles incorporating pyrazolylpyrazole moiety: synthesis, anti-HCV and antitumor activity.

Three series of novel pyrazole derivatives 2b-d, 4a-d and 6a-d were synthesized via two step procedure that utilizes hydrazonoyl chlorides 1a-d and enaminones 3a-d and 5a-d, respectively as starting materials. The structures of all the newly synthesized products have been established on the basis of analytical and spectral data. Moreover, some of the products 2-6 were tested against HCV and Subacute Sclerosing Panencephalitis (SSPE). In addition, compounds 2-6 were also tested for the inhibition of peroxynitrite-induced tyrosine nitration and antioxidant activity. The tested compounds are highly effective at very low concentration as anti-HCV, SSPE antioxidant and anticancer in the following ascending order 2d, 4c, 6b, 3b, 6c, 4d, 2b, 2c, 2a, 6a, 5b, 5a, 3a, 4b and 5c. It is worth to mention that all tested compounds are more potent than the reference standards used for comparing activity. All the measurements revealed that the mechanism of action of the anti cancer activities of all the tested compounds is topoisomerase I inhibitor.