Novel 1,3,4-heterodiazole analogues: synthesis and in-vitro antitumor activity

A Novel Method for the Syntheses of Imidazo-Thiadiazoles as Potential Antioxidants and Anti-Inflammatory Agents

BACKGROUND

A literature survey revealed that many imidazo-thiadiazole molecules were used as key intermediates for the development of novel drugs. The synthesized imidazo-thiadiazole derivatives were tested for their in vitro antioxidant and anti-inflammatory properties. The purpose of this research paper is to provide readers with information regarding diseases caused by free radicals.

OBJECTIVE

The objective of this study is to develop novel antioxidant and anti-inflammatory drugs.

METHODS

Imidazo-thiadiazole derivatives 5a-f were synthesized through cyclo-condensation reactions in two steps. First, the synthesis of 2-amino-thiadiazole derivatives from substituted aromatic carboxylic acids and thiosemicarbazide by using POCl₃ as a solvent as well as a catalyst was performed. In the next step, imidazo-thiadiazoles were prepared from 2-amino-thiadiazole derivatives with appropriate α-haloketones in the presence of polyethylene glycol-300 (PEG-300) as a green solvent. These imidazo- thiadiazole derivatives were prepared by using a novel method. The synthesized compounds were in vitro tested for their antioxidant and anti-inflammatory activities.

RESULTS

In vitro evaluation report showed that nearly all molecules possess potential antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO), superoxide radical (SOR), and hydrogen peroxide (H₂O₂) radical scavenging activity. Most of the imidazo-thiadiazole derivatives have shown significant anti-inflammatory activity as compared to diclofenac sodium as a reference standard.

CONCLUSION

In the search for novel therapies to treat inflammation and oxidation, we have made efforts to develop anti-inflammatory and antioxidant agents with a preeminent activity. Imidazo-thiadiazoles 5a, 5e as well as 5f showed potential anti-inflammatory activity. All tested imidazo-thiadiazole deriv-atives (5a-f) showed potential antioxidant activity against one more radical scavenging species as com-pared to ascorbic acid as the reference standard. Thus, imidazo-thiadiazole derivatives constitute an interesting template for the design and development of new antioxidant as well as anti-inflammatory agents.

A Three-Component Ugi-Type Reaction of N-Carbamoyl Imines Enables a Broad Scope Primary α-Amino 1,3,4-Oxadiazole Synthesis

A general synthesis of N-protected primary α-amino 1,3,4-oxadiazoles, from N-carbamoyl imines, N-isocyaniminotriphenylphosphorane (NIITP), and carboxylic acids, is described. Featuring an isocyanide addition reaction with N-carbamoyl imines, this efficient three-component Ugi-type reaction was found to be broad in scope with respect to imine, and carboxylic acid coupling partners. Furthermore, the versatility of this method was demonstrated by α-amino 1,2,4-triazole synthesis, the late-stage functionalization of seven drug molecules, and five divergent derivatizations of a primary α-amino 1,3,4-oxadiazole.

Synthesis, cytotoxic evaluation, and molecular docking studies of some new 1, 3, 4-oxadiazole-based compounds

Background and purpose

Oxadiazole-derived compounds have been shown to have a wide range of pharmacological activities. 2, 5-Disubstituted 1, 3, 4-oxadiazole derivatives have occupied a specific place in the design of anti-proliferative agents. In the present work a series of 2, 5-disubstituted 1, 3, 4-oxadiazoles derivatives containing amide group has been synthesized via a two-step reaction.

Experimental approach

A mixture of substituted carboxylic acid derivatives, semicarbazide, and phosphorus oxychloride in reflux condition yielded 2-amino-5-aryl-1, 3, 4-oxadiazole derivatives. Acylation of the amino group of the resultant oxadiazole with 6-chloronicotinoyl chloride in dry tetrahydrofuran/pyridine afforded the final products. The synthesized molecules were docked in the active sites of the epidermal growth factor receptor tyrosine kinase domain (PDB: 1M17) crystal structure to study the possible interactions with the active site. Cytotoxic activities of final products against HeLa and MCF-7 cells were also assessed by MTT assay.

Findings/Results

Compounds IIb, IIc, and IIe had a considerable cytotoxic activity with IC50 values of 19.9, 35, and 25.1 μM, respectively against HeLa cells. The highest docking score was -7.89 kcal/mol for compound IIe.

Conclusion and implications

Compound IIe exhibited remarkable cytotoxic activity against the two tested cell lines particularly HeLa cells which was in accordance with the in silico ΔG _bind result but further evaluations are necessary to prove these findings.

1,3,4-Oxadiazole Containing Compounds As Therapeutic Targets For Cancer Therapy

BACKGROUND

Cancer is the first or second leading cause of premature death in 134 of 183 countries in the world. 1,3,4-Oxadiazoles are five memebered heterocyclic rings containing two nitrogen (two atoms) and oxygen (one atom). They show better thermal stability, metabolic stability, aqueous solubility and lower lipophilicity than the other isomeric oxadiazoles. They are important class of heterocycles present in many drug structures like Raltegravir, Furamizole Tidazosin, Nesapidil, Setileuton (MK-0633) and Zibotentan. Presence of this nucleus in the therapeutics has made them an indispensable anchor for drug design and development. Several 1,3,4-oxadiazoles are prepared and reported as anticancer agents by numerous scientists worldwide.

OBJECTIVES

The present review discusses the anticancer potentials together with the molecular targets of 1,3,4-oxadiazoles reported since 2010. The structure activity relationship (SAR) and molecular docking simulation on different targets have also been discussed herein. Some of the important cancer targets have also been explored.

METHODS

The most potent 1,3,4-oxadiazoles reported in literature was highlighted in the manuscript. The anticancer activity was reported in terms of growth percent (GP), percent growth inhibition (%GI), GI50, IC50, and LC50 and TGI.

RESULTS

1,3,4-Oxadiazoles are an important heterocyclic scaffolds with broad spectrum biological activities. They may be either mono substituted or disubstituted and act as an indispensable anchor for drug design and discovery due to their thermal stability together with low lipophilicity. They exhibited anticancer potentials and showed the inhibitions of various cancer targets.

CONCLUSION

The discussion outlined herein will proved to be a helpful and vital tool for medicinal chemists investigating and working with 1,3,4-oxadiazoles and anticancer research programs.

QSAR and molecular docking studies of novel 2,5-distributed-1,3,4-thiadiazole derivatives containing 5-phenyl-2-furan as fungicides against Phythophthora infestans

Background

The 1,3,4-thiadiazoles are among the structural moieties that were found to be of utmost importance in the fields of pharmacy and agrochemicals because of their widespread biological activity that includes anti-tumor, antibacterial, anti-inflammatory, antihypertensive, anti-tuberculosis, anticonvulsant, and antimicrobial, among others.

Results

QSAR and molecular docking studies were carried out on thirty-two (32) derivatives of 2,5-disubstituted-1,3,4-thiadiazoles for their antifungal activities toward Phytophthora infestans. Using the “graphical user interface” of Spartan14 software, the structure of the compounds of the dataset is drawn and then optimized at DFT/B3LYP/6-31G* quantum mechanical method of the software. Molecular descriptors of the optimized compounds were calculated and later on divided into the training set and test sets (at a ratio of 3:1). The training set was used for model generation and the test set was for external validation of the generated model. Four models were generated by the employment of genetic function approximation (GFA) in which the optimal model (4) turned out to have the following statistical parameters: R2 = 0.798318, R2adj = 0.750864, cross-validation R2(Q2cv) = 0.662654, and external validation R2pred = 0.624008. On the molecular docking study of thiadiazole compounds with the target protein of Phytophthora infestans effector site (PDB ID: 2NAR ), compound 13 shows the highest binding affinity with − 9.3 kcal/mol docking score and composes hydrophobic as well as H-bond interactions with the target protein (2NAR).

Conclusion

The result of the QSAR study signifies the stability and robustness of the built model by considering the validation parameters and this gave an idea of template/ligand-based design while the molecular docking study revealed the binding interaction between the ligand and the protein site which gave an insight toward an “optimization method” of the structure-based design for the discovery of more potent compounds with better activity against Phytophthora infestans using the approach of computer-aided drug design (CADD) in plant pathology.

Anti-biofilm Fe3O4@C18-[1,3,4]thiadiazolo[3,2-a]pyrimidin-4-ium-2-thiolate Derivative Core-shell Nanocoatings

The derivatives 5,7-dimethyl[1,3,4]thiadiazolo[3,2-a]pyrimidin-4-ium-2-thiolate (1) and 7-methyl-5-phenyl[1,3,4]thiadiazolo[3,2-a]pyrimidin-4-ium-2-thiolate (2) were fully characterized by single-crystal X-ray diffraction. Their supramolecular structure is built through both π–π stacking and C=S–π interactions for both compounds. The embedment of the tested compounds into Fe₃O₄@C₁₈ core-shell nanocoatings increased the protection degree against Candida albicans biofilms on the catheter surface, suggesting that these bioactive nanocoatings could be further developed as non-cytotoxic strategies for fighting biofilm-associated fungal infections.

Synthesis of Hydrophobic Propionyl Neohesperidin Ester Using an Immobilied Enzyme and Description of Its Anti-proliferative and Pro-apoptotic Effects on MCF-7 Human Breast Cancer Cells

Neohesperidin (NH) is a natural flavonoid glycoside compound with considerable physiological and pharmacological activities. However, its bioavailability is limited due to poor solubility, and few studies have so far attempted improve the solubility and bioavailability of NH. In this study, we structurally modified NH using an immobilized lipase to improve lipophilicity and therefore expand its applicability in lipophilic media as well as enhance its bioavailability in vivo. In addition, we aimed investigated the pro-apoptoptotic activity of this new compound (propionyl neohesperidin ester, PNHE) in MCF-7 breast cancer cells using a variety of cellular assays, including the MTT (3-(4, 5-dimethyl- 2-thiazolyl)-2, 5-diphenyl-2-h-tetrazolium bromide assay, assessment of intracellular reactive oxygen species (ROS) levels, and flow cytometry. We successfully synthesized PNHE using immobilized lipases, and the esterification of NH was confirmed by Fourier transform-infrared spectroscopy (FT-IR). Compared to NH, HNPE showed higher anti-proliferative and pro-apoptotic in MCF-7 breast cancer cells, which may be explained by its increased lipophilicity compared to neohesperidin, benefiting to the action of NH on the cancer cell wall. The IC₅₀ of PNHE for inducing apoptosis of MCF-7 cells was 185.52 μg/mL. PNHE increased both the proportion of cells in Sub-G1 phase and the cellular ROS content, indicating a certain therapeutic effect of HNPE on breast cancer.

Thiazole-containing compounds as therapeutic targets for cancer therapy

In the last few decades, considerable progress has been made in anticancer agents development, and several new anticancer agents of natural and synthetic origin have been produced. Among heterocyclic compounds, thiazole, a 5-membered unique heterocyclic motif containing sulphur and nitrogen atoms, serves as an essential core scaffold in several medicinally important compounds. Thiazole nucleus is a fundamental part of some clinically applied anticancer drugs, such as dasatinib, dabrafenib, ixabepilone, patellamide A, and epothilone. Recently, thiazole-containing compounds have been successfully developed as possible inhibitors of several biological targets, including enzyme-linked receptor(s) located on the cell membrane, (i.e., polymerase inhibitors) and the cell cycle (i.e., microtubular inhibitors). Moreover, these compounds have been proven to exhibit high effectiveness, potent anticancer activity, and less toxicity. This review presents current research on thiazoles and elucidates their biological importance in anticancer drug discovery. The findings may aid researchers in the rational design of more potent and bio-target specific anticancer drug molecules.

Synthesis, docking and anticancer activity of azo-linked hybrids of 1,3,4-thia-/oxadiazoles with cyclic imides

A series of novel analogues based on a diazole-imide pharmacophore were synthesized by diazotizing substituted 1,3,4-thia-/oxadiazol-2-amines and subsequently coupling the resulting diazonium salts with N-substituted cyclic imides. The resulting compounds C1 to C28 were characterized by various spectral methods, viz. IR, NMR and mass spectroscopy. All the synthesized compounds were tested against two human cancer cell lines: human breast adenocarcinoma cell line MCF-7 and colorectal adenocarcinoma cell line HT-29. Among the synthesized compounds, C14 (2-(4-chloro-3-((5-(4-nitrophenyl)-1,3,4-thiadiazol-2-yl)diazenyl)phenyl)-4,5,6,7-tetrahydro-1H-isoindole-1,3(2H)-dione) emerged as a potential candidate against both MCF-7 and HT-29 with [Formula: see text] values of 0.09 ± 0.02 [Formula: see text]M and 0.11 ± 0.03 [Formula: see text]M, respectively. Similarly, compound C16 displayed highest anticancer activity against MCF-7 cell line with [Formula: see text] = 0.07 ± 0.02 [Formula: see text]M. Target fishing (inverse docking) using ChemMapper server identified EGFR tyrosine and CDK2 kinases as high priority targets for this pharmacophore. Computational docking (AutoDock 4.2) was used to analyse the interactions between the target proteins and active compounds.

Synthesis and cytotoxic activity of certain benzothiazole derivatives against human MCF-7 cancer cell line

A new series of benzothiazole has been synthesized as cytotoxic agents. The new derivatives were tested for their cytotoxic activity toward the human breast cancer MCF-7 cell line against cisplatin as the reference drug. Many derivatives revealed good cytotoxic effect, whereas four of them, 4, 5c, 5d, and 6b, were more potent than cisplatin, with IC₅₀ values being 8.64, 7.39, 7.56, and 5.15 μm compared to 13.33 μm of cisplatin. The four derivatives' cytotoxic activity was accompanied by regulating free radicals production, by increasing the activity of superoxide dismutase and depletion of intracellular reduced glutathione, catalase, and glutathione peroxidase activities, accordingly, the high production of hydrogen peroxide, nitric oxide, and other free radicals causing tumor cell death as monitored by reduction in the synthesis of protein and nucleic acids. Most of the tested compounds showed potent to moderate growth inhibitory activity; in particular, compound 6b exhibited the highest activity suggesting it is a lead compound in cytotoxic activity.

QSAR models of antiproliferative activity of imidazo[2,1-b][1,3,4]thiadiazoles in various cancer cell lines

Imidazo[2,1-b][1,3,4]thiadiazoles have been recognized to possess antiproliferative potency towards a wide spectrum of cancer cell lines. QSAR investigations on a set of 42 di(tri)substituted imidazo[2,1-b][1,3,4]thiadiazoles were carried out to find the descriptors determining their biological potency. Three-variable equations were obtained by combinatorial protocols in multiple linear regression (CP MLR) for all three studied cancer cell lines. They showed that lipophilicity, electronic, and steric factors are decisive for the antiproliferative potency of compounds and indicate the important role of nitrogen atoms of imidazothiadiazole ring in the interactions with the molecular target. The best models gave high r squared values in the range from 0.887 to 0.924. They also have good predictive accuracy confirmed by the high value LOO cross-validation coefficient [Formula: see text] (from 0.842 to 0.904) and by the external validation quantities.

Structure-activity relationship (SAR) study and design strategies of nitrogen-containing heterocyclic moieties for their anticancer activities

The present review article offers a detailed account of the design strategies employed for the synthesis of nitrogen-containing anticancer agents. The results of different studies describe the N-heterocyclic ring system is a core structure in many synthetic compounds exhibiting a broad range of biological activities. Benzimidazole, benzothiazole, indole, acridine, oxadiazole, imidazole, isoxazole, pyrazole, triazoles, quinolines and quinazolines including others drugs containing pyridazine, pyridine and pyrimidines are covered. The following studies of these compounds suggested that these compounds showed their antitumor activities through multiple mechanisms including inhibiting protein kinase (CDK, MK-2, PLK1, kinesin-like protein Eg5 and IKK), topoisomerase I and II, microtubule inhibition, and many others. Our concise representation exploits the design and anticancer potency of these compounds. The direct comparison of anticancer activities with the standard enables a systematic analysis of the structure-activity relationship among the series.

Synthesis, biological evaluation and molecular modeling study of some new methoxylated 2-benzylthio-quinazoline-4(3H)-ones as nonclassical antifolates

A new series of 2,3,6-substituted-quinazolin-4-ones was designed, synthesized, and evaluated for their in vitro DHFR inhibition, antimicrobial, and antitumor activities. Compounds 28 and 61 proved to be active DHFR inhibitors with IC50 0.02 and 0.01μM, respectively. Molecular modeling studies concluded that recognition with the key amino acid Phe34 is essential for binding and hence DHFR inhibition. Compounds 34, 56 and 66 showed broad spectrum antimicrobial activity comparable to Gentamicin and Ciprofloxacin. Compounds 40 and 64 showed broad spectrum antitumor activity toward several tumor cell lines and proved to be 10 fold more active than 5-FU, with GI50 MG-MID values of 2.2 and 2.4μM, respectively.

Ultrasound Mediated One-Pot, Three Component Synthesis, Docking and ADME Prediction of Novel 5-Amino-2-(4-chlorophenyl)-7-Substituted Phenyl-8,8a-dihydro-7H-(1,3,4)thiadiazolo(3,2-α)pyrimidine-6-carbonitrile Derivatives as Anticancer Agents

Herein, we report an environmentally friendly, rapid, and convenient one-pot ultrasound-promoted synthesis of 5-amino-2-(4-chlorophenyl)-7-substituted phenyl-8,8a-dihydro-7H-(1,3,4)thiadiazolo(3,2-α)pyrimidine-6-carbonitrile derivatives. The in-vitro anticancer activities of these compounds were evaluated against four human tumor cell lines. Among all the synthesized derivatives, compound 4i, which has substituent 3-hydroxy-4-methoxyphenyl is found to have the highest GI₅₀ value of 32.7 μM, 55.3 μM, 34.3 μM, 28.9 μM for MCF-7, K562, HeLa and PC-3 cancer cell lines respectively. A docking study of the newly synthesized compounds were performed, and the results showed good binding mode in the active site of thymidylate synthase enzyme. ADME properties of synthesized compounds were also studied and showed good drug like properties.

Synthesis and fungicidal activity of novel 2,5-disubstituted-1,3,4- thiadiazole derivatives containing 5-phenyl-2-furan

A series of 2,5-disubstituted-1,3,4-thiadiazoles were synthesized using Lawesson’s reagent by an efficient approach under microwave irradiation in good yields. Their structures were characterized by MS, IR, ¹H NMR, ¹³C NMR, and elemental analysis. Their in vitro and in vivo fungicidal activities revealed that the title compounds exhibited considerable activity against five selected fungi, especially to Phytophthora infestans. In order to illustrate the mechanism of title compounds against P. infestans, scanning electron micrographs (SEM) and transmission electron micrographs (TEM) were applied. The morphological and ultrastructural studies demonstrated that compound I18 led to swelling of hyphae, thickening and proliferating multilayer cell walls, excessive septation and accumulation of dense bodies. The bioassay results indicated compound I18 might act on cell wall biosynthesis, and blocked the nutrition transportation and led to cells senescence and death. Meanwhile, compound I18 had broad fungicidal activity against other twenty different kinds of fungi. These results suggested that title compounds were eligible to be development candidates and compound I18 as a promising lead compound was worthy to be further discovery, especially against P. infestans.

Synthesis and Cytotoxic Effect of Some Novel 1,2-Dihydropyridin-3-carbonitrile and Nicotinonitrile Derivatives

1-(2,4-Dichlorophenyl)-3-(4-fluorophenyl)propen-1-one (1) was prepared and reacted with an active methylene compound (ethyl cyanoacetate) in the presence of ammonium acetate to give the corresponding cyanopyridone 2. Compound 2 reacted with hydrazine hydrate, malononitrile, ethyl bromoacetate and phosphorous oxychloride to afford compounds 4 and 7–11, respectively. The 2-chloropyridine derivative 11 reacted with different primary amines, namely benzyl amine, piperonyl amine, 1-phenylethyl amine, and/or the secondary amines 2-methyl-pipridine and morpholine to give the corresponding derivatives 12–15. Hydrazinolysis of chloropyridine derivative 11 with hydrazine hydrate afforded the corresponding hydrazino derivative 17. Condensation of compound 17 with ethyl acetoacetate, acetylacetone, isatin and different aldehydes gave the corresponding derivatives 18–21. Some of newly synthesized compounds were screened for cytotoxic activity against three tumor cell lines. The results indicated that compounds 8 and 16 showed the best results, exhibiting the highest inhibitory effects towards the three tumor cell lines, which were higher than that of the reference doxorubicin and these compounds were non-cytotoxic towards normal cells (IC₅₀ values > 100 μg/mL).

Antimicrobial and antiquorum-sensing studies. Part 3: Synthesis and biological evaluation of new series of [1,3,4]thiadiazoles and fused [1,3,4]thiadiazoles

New series of [1,3,4]thiadiazoles and fused [1,3,4]thiadiazoles were synthesized. The newly synthesized compounds were screened for their antibacterial activity against Staphylococcus aureus, Bacillus cereus, and Escherichia coli. Compounds 3b and 10a displayed the highest activity against E. coli with MIC value of 78.125 μg/mL. In addition, compound 10a exhibited the highest activity against B. cereus with MIC value of 156.25 μg/mL. The antifungal activity of these compounds was also tested against Candida albicans and Aspergillus flavus 3375. Compounds 3b, 5a, 10a, and 12b showed the best activity against A. flavus 3375 with MIC value of 19.531 μg/mL. The same compounds were examined for their antiquorum-sensing activity against Chromobacterium violaceum ATCC 12472, whereas compounds 3b, 5a, and 12b exhibited moderate activity. In vitro cytotoxicity testing of compounds 3b,c, 5a, 6a, 10a, and 12a,b against human normal lung fibroblast (W138) cell line was performed. The in vivo acute toxicity of the same compounds was also tested and the obtained results indicated that compound 10a is the least toxic analog. The same compounds were studied for their DNA-binding affinity and the obtained results showed that compounds 3b, 10a, and 12a,b have moderate DNA-binding affinity.

Induction and mechanism of HeLa cell apoptosis by 9-oxo‑10, 11-dehydroageraphorone from Eupatorium adenophorum

9-Oxo-10, 11-dehydroageraphorone (euptox A), a cadenine sesquiterpene, is the main toxin from Eupatorium adenophorum. The aim of the present study was to examine the induction and mechanism of HeLa cell apoptosis by euptox A. The apoptosis‑inducing effect of the euptox A on HeLa cells was examined by MTT assay. The underlying mechanism was analyzed by flow cytometry and quantitative PCR. Flow cytometry results suggested that euptox A effectively inhibited the proliferation of HeLa cells, arrested the cell cycle transition from S to G2/M phase, did not continue to complete the cell cycle activity (mainly from 4 times and mitosis), and induced cell proliferation. The RT-qPCR detection results showed that euptox A induced apoptosis by improving the gene expression level of apoptotic proteases such as caspase-10 in HeLa cells. Its mechanism of action was associated with the upregulation of apoptotic gene expression and arresting of the cell cycle.

Imidazothiazole and related heterocyclic systems. Synthesis, chemical and biological properties

Fused heterobicyclic systems have gained much importance in the field of medicinal chemistry because of their broad spectrum of physiological activities. Among the heterocyclic rings containing bridgehead nitrogen atom, imidazothiazoles derivatives are especially attractive because of their different biological activities. Since many imidazothiazoles derivatives are effective for treating several diseases, is interesting to analyze the behavior of some isosteric related heterocycles, such as pirrolothiazoles, imidazothiadiazoles and imidazotriazoles. In this context, this review summarizes the current knowledge about the syntheses and biological behavior of these families of heterocycles. Traditional synthetic methodologies as well as alternative synthetic procedures are described. Among these last methodologies, the use of multicomponent reaction, novel and efficient coupling reagents, and environmental friendly strategies, like microwave assistance and solvent-free condition in ionic liquids are also summarized. This review includes the biological assessments, docking research and studies of mechanism of action performed in order to obtain the compounds leading to the development of new drugs.

Synthesis, spectral characterization and antimicrobial studies of nano-sized oxovanadium(IV) complexes with Schiff bases derived from 5-(phenyl/substituted phenyl)-2-hydrazino-1,3,4-thiadiazole and indoline-2,3-dione

A new class of oxovanadium(IV) complexes with Schiff bases derived by the condensation of 5-(phenyl/substituted phenyl)-2-hydrazino-1,3,4-thiadiazoles and indoline-2,3-dione have been prepared in ethanol in the presence of sodium acetate. Micro-analytical data, magnetic susceptibility, UV-Vis, IR, EPR and XRD spectral techniques were used to confirm the structures. Electronic absorption spectra of the complexes suggest a square-pyramidal geometry. The oxovanadium(IV) complexes have monoclinic crystal system and particle sizes were found to be in the range 18.0 nm to 24.0 nm (nano-size). In vitro antifungal activity of synthesized compounds was determined against fungi Aspergillus niger, Colletotrichum falcatum and Colletotrichum pallescence and in vitro antibacterial activity was determined by screening the compounds against Gram-negative (Escherichia coli and Salmonella typhi) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacterial strains. The oxovanadium(IV) complexes have higher antimicrobial effect than free ligands.

Novel acetamidothiazole derivatives: synthesis and in vitro anticancer evaluation

A novel series of acetamide derivatives possessing both 2-imino-4-arylthiazoles and morpholine or different piperazines were synthesized and characterized by IR, (1)H NMR, (13)C NMR, elemental and mass spectral analyses. Twelve compounds were granted NSC codes at National Cancer Institute (NCI), USA for anticancer activity at a single high dose (10(-5) M) in full NCI 60 cell panel. Among the compounds tested, compounds 5a and 6b were found to be the most active candidates of the synthesized series. Assessment of toxicities, druglikeness, and drug score profiles of compounds 5a and 6b are promising. Some of the synthesized compounds showed a good docking score with potential anticancer targets, chosen based on pharmacophore mapping of the established derivatives.

Synthesis, spectral and antimicrobial activity of Zn(II) complexes with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde/2-hydroxyacetophenone/indoline-2,3-dione

Zn(II) complexes have been synthesized by reacting zinc acetate with Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/benzaldehyde/indoline-2,3-dione. All these complexes are soluble in DMF and DMSO; low molar conductance values indicate that they are non electrolytes. Elemental analyses suggest that the complexes have 1:2 metal to ligands stoichiometry of the types [ZnL2(H2O)2](L=monoanionic Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and 2-hydroxyacetophenone/indoline-2,3-dione) [ZnL2(')(OOCCH3)2(H2O)2](L'=neutral Schiff bases derived from 2-hydrazino-5-[substituted phenyl]-1,3,4-thiadiazole and benzaldehyde), and they were characterized by IR, (1)H NMR, and (13)C NMR. Particle sizes of synthesized compounds were measured with dynamic light scattering (DLS) analyser which indicates that particle diameter are of the range ca. 100-200nm. All these Schiff bases and their complexes have also been screened for their antibacterial (Bacillus subtilis (B. subtilis), Escherichia coli (E. coli) and antifungal activities (Colletotrichum falcatum (C. falcatum), Aspergillus niger (A. niger), Fusarium oxysporium (F. oxysporium) Curvularia pallescence (C. pallescence). The antimicrobial activities have shown that upon complexation the activity increases.

Synthesis, antitumor and antimicrobial testing of some new thiopyrimidine analogues

The synthesis of some new 4-chloro-pyrimidine-5-carbonitriles (3b-d), 4-substituted-amino-pyrimidine-5-carbonitriles (4a-g), trioxo and dioxo-thiazolo[3,2-a]pyrimidine-6-carbonitriles (5a-c and 6a-h) have been described. The obtained compounds were evaluated for their in-vitro antitumor activity. A single dose (10 µM) of the test compounds was used in the National Cancer Institute (NCI) 60 cell lines panel assay. Compounds 3c and 4f showed high inhibitory activity against leukemia, whereas, compounds 3b and 4d, g displayed moderate activity. On the other hand, all compounds were screened for their in-vitro antibacterial and antifungal activities. Compounds 3d and 4b exhibited significant antibacterial activity against Staphylococcus aureus. Compound 4e showed two folds inhibitory activity against Entrobacter aerogener compared with the reference drug Tobramycin.

Benzimidazole clubbed with triazolo-thiadiazoles and triazolo-thiadiazines: new anticancer agents

Two series of Benzimidazole clubbed with triazolo-thiadiazoles (5a-q, 5r, 5s and 5x-a(1)) and triazolo-thiadiazines (5t-w) were synthesized with an aim to produce promising anticancer agents. In vitro anticancer activities of synthesized compounds were investigated at the National Cancer Institute (NCI) against NCI 60 cell line panel; results showed good to remarkable broad-spectrum anticancer activity. Among them, the compound 5h (NCS: 760452, 1-(1H-benzo [d] imidazol-2-yl)-3-(6-(2,4-dichlorophenyl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-3-yl) propan-1-one) exhibited significant growth inhibition with GI50 values ranging from 0.20 to 2.58 μM and found superior selectivity for the leukemia cell lines and further screened at 10-fold dilutions of five different concentrations (0.01, 0.1, 1, 10 and 100 μM). The 5h may possibly be used as lead compound for developing new anticancer agents.