Zn(OTf)2-catalyzed three component, one-pot cyclocondensation reaction of some new octahydroquinazolinone derivatives and access their bio-potential

An efficient synthesis of some new octahydroquinazolinone derivatives 4a–x by the cyclocondensation reaction of corresponding 2-thi(oxo)-1,2-dihydroquinoline-3-carbaldehyde 1a–e, 1,3-dicarbonyl compounds 2a–b, and substituted urea 3a–c using zinc triflate as a catalyst in refluxing ethanol in high yield is described. The structures of new compounds have been characterized on the basis of elemental analysis, FT- IR, ¹H NMR, ¹³C NMR, and mass spectral data. All the synthesized compounds were evaluated for their antimicrobial activities against various microbes. Minimum inhibitory concentration values of all the 24 synthesized compounds were also determined. Some of the synthesized compounds exhibited excellent antimicrobial activity.     

Thiourea and thioether derivatives of sorafenib: synthesis, crystal structure, and antiproliferative activity

A series of novel sorafenib derivatives containing diaryl thiourea and thioether, 9a–u, was designed and synthesized, and their antiproliferative activities against HCT116 and MDA-MB-231 cell lines were also evaluated and described. Most compounds exhibited potent antiproliferative activity against HCT116 cells with IC₅₀ = 1.8–80.4 μM. Compounds 9p, 9r, and 9s demonstrated competitive antiproliferative activities to sorafenib, against all two cancer cell lines. The structures of all the newly synthesized compounds were determined by ¹H NMR, ¹³C NMR, and HRMS, and compound 9n was characterized by single-crystal X-ray diffraction. Primary structure–activity relationships (SAR) have also been established.     

Synthesis, characterization, and in vitro antimicrobial evaluation of new 5-chloro-8-bromo-3-aryl-1,2,4-triazolo[4,3-c]pyrimidines

A series of new 5-chloro-8-bromo-3-aryl-1,2,4-triazolo[4,3-c]pyrimidines (4a–j) have been accomplished in excellent yields by the oxidative cyclization of pyrimidinylhydrazines (3a–j) of various aryl aldehydes with one equivalents of iodobenzene diacetate in methanol. The chemical structures of the synthesized compounds were confirmed by elemental analyses, FT-IR, ¹H NMR, ¹³C NMR, and mass spectral studies. Ten new compounds (4a–j) were tested in vitro for their antimicrobial activity against clinically isolated strains. Variable and modest activities were observed against the investigated strains of bacteria and fungi. Compounds 4f, 4i, and 4j demonstrated good antimicrobial activity against all the tested microbial strains.     

Synthesis, antimicrobial and antioxidant activities of 2-[1-{3,5-diaryl-4,5-dihydro-1H-pyrazolenyl}]-4-(4-nitrophenyl)-[1,3]-thiazoles

In this study, various substituted chalcones, prepared by condensing substituted acetophenones with substituted aldehydes/arylfurfurals, were treated with thiosemicarbazide in basic media to produce 1-thiocarbonyl-3,5-disubstituted pyrazolines which on further reaction with substituted phenacyl bromides afforded the title compounds in good yield. Structures of the newly synthesized compounds were assigned on the basis of elemental analyses, IR, ¹H NMR, and mass spectral studies. The newly synthesized compounds were tested for their in vitro antibacterial and antifungal activities against a variety of microorganisms and antioxidant activities by diphenylpicrylhydrazyl radical scavenging assay. Among the derivatives, compounds 3b, 3e, 6a, and 6h were identified as potent antioxidants. Compounds 3d, 3e, and 6a–f have emerged as the most promising antimicrobial agents displaying the maximum activity against all the tested microorganisms.     

Synthesis,antimicrobial, and cytotoxic activities of novel benzimidazole derivatives bearing cyanopyridine and 4-thiazolidinone motifs

A series of 6-(1H-benzo[d]imidazol-2-yl)-2-(2-(3-nitrophenyl)-4-oxothiazolidin-yl)-4-(aryl)nicotinonitriles 5a–l were synthesized and characterized by IR, ¹H NMR, ¹³C NMR, and mass spectrometry techniques. These novel compounds 5a–l were screened for their in vitro antimicrobial activity against different bacterial and fungal strains and in vitro cytotoxicity study (HeLa cell line) using MTT colorimetric assay. The results demonstrated that compounds 5c, 5e, and 5i–k exhibited excellent antibacterial activity, while compounds 5d, 5i, and 5k were found to be the most potent antifungal agents. From the standpoint of SAR studies, it was observed that the presence of electron donating groups remarkably enhanced the antimicrobial activity of newly synthesized compounds. Further, the results of preliminary MTT cytotoxicity studies on HeLa cells suggested that potent antimicrobial activity of 5c–e and 5i–k was accompanied by low cytotoxicity.     

Synthesis, characterization, and antimicrobial evaluation of novel naphthalene-based 1,2,4-triazoles

In order to search for new bioactive molecules with significant antimicrobial action, a series of 1,2,4-triazole and naphthalene analogs bearing structurally diverse substituents, N-(3-mercapto-5-(naphthalen-1-yl)-4H-1,2,4-triazol-4-yl)(aryl)amides 3a–l were synthesized in good yield by a multi-step synthetic procedure. Their antimicrobial activity was screened against various Gram-positive and Gram-negative bacteria and fungi. Compounds 3a, 3f, 3g, 3j, and 3k exerted strong inhibition of the investigated bacterial and fungal strains compared to control antibiotic ampicillin and antifungal griseofulvin. On the basis of statistical analysis, it is observed that the compounds give significant co-relation. All the synthesized compounds have been characterized by IR, ¹H NMR, ¹³C NMR, and mass spectral data.     

Antimicrobial and anticancer effects of some 2-(substitutedsulfanyl)-N-(5-methyl-isoxazol-3-yl)acetamide derivatives

In the present study, some isoxazole-(benz)azole derivatives (3a–3j) were synthesized by considering antimicrobial and anticancer potencies of azole compounds. Chemical structures of obtained compounds (3a–3j) were confirmed by the data of spectral and elemental analyses. Anticancer activity evaluation was performed at two steps. Initially, cytotoxic effects of the compounds (3a–3j) on HT-29 (colon carcinoma) and C-6 (melanoma) cell lines were determined by MTT assay. Secondly, the compounds 3g–3i, which indicated significant cytotoxicity were selected and analysed for their inhibitory activity on DNA synthesis of carcinogenic cells. The compounds 3g and 3h showed notable DNA synthesis inhibition on both cancer cell lines. Antibacterial and antifungal activities of the synthesized compounds (3a–3j) were also examined. All of the compounds exhibited very poor antibacterial activity against gram negative and gram positive bacterial strains, whereas antifungal activity of the compounds 3a–3f was equal to that of Ketoconazole.     

Synthesis and biological evaluation of novel 4,5-dihydropyrazole derivatives as potent anticancer and antimicrobial agents

A focused library of 4,5-dihydropyrazole dervivatives (4, 5, 6, 7a–h, 8, 9a–g, and 10a–g) were synthesized from novel 5-(2,6-difluorophenyl)-3-phenyl-4,5-dihydropyrazole-1-carbothioamide 4. The synthesized compounds were characterized using elemental analysis and spectral data (IR, mass spectra, ¹H and ¹³C NMR) and evaluated for antimicrobial activity by broth dilution method and in vitro anticancer activity. Among the synthesized compounds 7a, 9c, 9g, and 10d exhibit broad spectrum antimicrobial activity against tested microbial strains. The in vitro cancer results ascertain 7a, 9c, and 10d are most potent molecules in comparison to reference standard cisplatin.     

Synthesis, in vitro cytotoxicity, and antibacterial studies of new asymmetric bis-1,2,4-triazoles

A series of asymmetric bis-1,2,4-triazoles (4a–l) were synthesized from respective 1,2,4-triazole-3-thiocarbohydrazides (2a, b) via base catalyzed dehydrative cyclization of thiosemicarbazide intermediates (3a–l). The synthesized compounds were characterized by IR, ¹H-NMR, ¹³C-NMR, and Mass spectral studies. The asymmetric bis-1,2,4-triazole derivatives (4a–l) were evaluated for in vitro antioxidant activity by DPPH radical scavenging assay method. The compounds with significant antioxidant potential were evaluated for in vitro cytotoxicity by MTT assay method against HT29 (Human adenocarcinoma) and MDA-231 (Human breast cancer) cancer cell lines. All the synthesized compounds were evaluated for in vitro antibacterial activity against Bacillus subtilus (ATCC 6633), Staphylococcus aureus (ATCC-25923), Escherichia coli (ATCC-25922), and Pseudomonas aeruginosa (ATCC-27853).     

Synthesis, characterization, and antimicrobial studies of novel 1,3,4-thiadiazolium-5-thiolates

Sixteen novel thiadiazolium derivatives 6(a–h) and 12(a–h) were synthesized by conventional route starting from anthranilic acid using different acid chloride derivatives. The structure of all the newly synthesized compounds was established by IR, NMR, mass spectroscopy, and elemental analysis. The compounds were also screened for their antibacterial activity against some important bacterial species. Some of the compounds were found excellent active against these species.     

Synthesis,antimicrobial, and antioxidant activity of benzofuran barbitone and benzofuran thiobarbitone derivatives

The synthesis of novel series of benzofuran derivatives, containing barbitone moiety, 5-[(2/4-substitutedphenyl)(5-substituted-1-benzofuran-2-yl) methylidene]pyrimidin-2,4,6(1H,3H,5H)-trione (4a–i) and thiobarbitone moiety, 5-[(2/4-substitutedphenyl)(5-substituted-1-benzofuran-2-yl)methylidene]-2-thioxodihydropyrimidin-4,6(1H, 5H)-dione (5a–i) have been reported. The target compounds (4a–i) and (5a–i) were synthesized by the Knoevenagel condensation of (5-substituted-1-benzofuran-2-yl)(2/4-substitutedphenyl) methanone (3a–i) with barbituric acid and thiobarbituric acid, respectively, in acid medium. These compounds were screened for the antimicrobial and antioxidant activities. From antimicrobial activity results it was found that compounds 4a, 5a, 4c, and 5c displayed good antibacterial and antifungal activity against all tested strains. Further, the synthesized compounds were studied for docking on the enzyme, Glucosamine-6-phosphate synthase and the compounds 4c and 5c have emerged has an active antimicrobial agent with least binding energy (?5.27 and ?4.85 kJ mol^?1). Compounds 4e, 4f, 5e, and 5f showed promising free radical scavenging activity and compounds 5a and 5b showed good chelating ability with Fe²⁺ ions.     

An efficient, solvent-free microwave-assisted synthesis and antimicrobial screening of 1,6-dihydropyrimidine analogues

A series of compounds 4-(4-(4-aminophenyl)-6-(aryl)-1,6-dihydropyrimidin-2-ylthio)butanenitriles 5a–l were synthesised by the reaction of allyl cyanide 4 with 3a–l. Compounds 3a–l were prepared from reaction between various chalcones 1a–l and thiourea in presence of catalytic amount of potassium hydroxide. Compounds 3a–l, and 5a–l were prepared by classical as well as MWI methods. Structures of the compounds were characterized by IR, ¹H NMR, ¹³C NMR and mass spectral data. The newly synthesized compounds 5a–l were screened for their antimicrobial activity against different strains of bacteria and fungi using serial broth dilution method. Compounds 5e, 5g and 5k were found to be most active with MIC of 25?μg/mL against selected bacterial strains, while compound 5d, 5f, 5j and 5k were found to be most active with MIC 50?μg/mL against selected fungal strains.     

Synthesis and evaluation of analgesic, anti-inflammatory, and anticancer activities of new pyrazole-3(5)-carboxylic acid derivatives

In this article, we synthesized a series of novel 1-benzyl-5(3)-p-tolyl-1H-pyrazole-3(5)-carboxylic acid derivatives and characterized by IR, ¹H NMR, and mass spectroscopy. Compounds were evaluated for their in vivo analgesic and anti-inflammatory activity using the p-benzoquinone-induced writhing test and the carrageenan-induced paw edema model, respectively. Out of 14 compounds tested, 7a, 7c, 7e, 7f, 7i, 8a–b, and 8f–g exhibited potent analgesic and/or anti-inflammatory activity as compared to reference drugs aspirin and indomethacin. Anticancer activity of these compounds was assessed against five cancer cell lines with the MTT assay (HL-60, human promyelocytic leukemia cells; HeLa, human cervical cancer cells; Raji, human B lymphocyte cell line; MCF7, human breast adenocarcinoma cell line; MDA-MB-231, estrogen-independent human breast cancer cell line). Compounds 7a, 8a, and 8b with high anti-inflammatory activity, and also 7d and 7j with mild anti-inflammatory activity exhibited promising anticancer activity against some selected cell lines.     

Synthesis and anticonvulsant activity of some new series of pyrrole derivatives

A new series of compounds 3a–f were synthesized from condensation method. Newly synthesized compounds were established by IR, ¹H NMR, ¹³C NMR, mass spectral and elemental analysis. Synthesized compounds 3a–f were screened for anticonvulsant activity. The compound 2,2′-({3-methyl-5-[2-phenylethenyl]-1H-pyrrole-2,4-diyl}dicarbonyl)dihydrazinecarbothioamide 3a showed significant activity compared with other compounds 3b–f against pentamethylene tetrazole-induced seizures.     

Design, synthesis, and biologic evaluation of some novel N-arylpyrazole derivatives as cytotoxic agents

A novel series of N-arylpyrazole derivatives (5a–5d, 7a–7c) has been designed and synthesized via aromatic substitution reaction of N-nonsubstituted pyrazoles with 4-fluoronitrobenzene in the presence of base. The structures of these compounds were established on the basis of elemental (C, H, and N) and spectral analysis (¹H NMR, ¹³C NMR, HRMS, and FT-IR). All the compounds were tested for their cytotoxic activity in vitro against four human tumor cell lines: carcinoma (Bel-7402), nasopharyngeal carcinoma (KB), immature granulocyte leukemia (HL-60), and gastrocarcinoma (BGC-823) by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The results showed that most of the obtained compounds exhibited promising cytotoxicity against tested carcinoma cell lines with low IC₅₀ values. The bis-pyrazole derivative 7c, bearing alkoxy group on the 5-position of phenyl ring, was the most effective one. It is inhibition of cell growth of Bel-7402 cells was 1.5-fold higher than that found for cisplatin. And, also mono-pyrazole derivatives 5a and 5b, decorated with trifluoromethyl group on the phenyl ring, displayed better cytotoxicity than that of cisplatin against Bel-7402 cell line.     

Antimicrobial and antiquorum-sensing studies. Part 2: synthesis, antimicrobial, antiquorum-sensing and cytotoxic activities of new series of fused [1,3,4]thiadiazole and [1,3]benzothiazole derivatives

New series of [1,3,4]thiadiazolo[3,2-a]pyrimidines, [1,3,4]thiadiazolo[2,3-b]quinazolines, and pyrimido[2,1-b][1,3]benzothiazoles have been synthesized and characterized by analytical and spectrometrical methods (IR, MS, ¹H, and ¹³C NMR). Sixteen of the synthesized compounds; namely, 3a, b, 5a–f, 8a, b, 10, 11a–c, and 13a, b were screened for antibacterial activity against Escherichia coli, Staphylococcus aureus, and Bacillus cereus. They were found to be either moderately active, slightly active or inactive against the selected microorganisms. The antifungal activity of these compounds were also tested against Candida albicans, Aspergillus fumigatus 293, and Aspergillus flavus 3375. Compound 11a showed potent antifungal activity against the three selected fungi; the rest of the tested compounds displayed either weaker activity or were completely inactive. The same compounds were examined for antiquorum-sensing activity against Chromobacterium violaceum ATCC 12472, where compounds 3a, 10, 11a, and 13a, b exhibited promising activity. The in vitro cytotoxic activity of these compounds was also studied by brine shrimp lethality bioassay, and results indicated that compounds 3a, 11a, and 13a have the highest cytotoxic activity.     

Design, synthesis of some 2,6,9-trisubstituted purinyl thioureido derivatives and evaluation of antimicrobial activity

Some new trisubstituted purinyl thioureido were synthesized and evaluated for their in vitro antimicrobial activity against Gram positive and Gram negative strains and antifungal strain using a micro dilution procedure. Synthesized compounds 6a–j prove to be effective with minimum inhibitory concentration (MIC) (mg?ml^?1), among them 6a, 6d, and 6e showed excellent activity against a panel of microorganisms. The newly synthesized compounds were characterized using IR, ¹H-NMR, and elemental analysis.     

Synthesis and biological evaluation of novel quinazoline derivatives obtained by Suzuki C–C coupling

In the present investigation, two series of novel urea/thiourea-based quinazoline analogs (7a–g/8a–g) have been synthesized by introducing C–C Suzuki coupling between quinazoline and phenyl ring followed by condensation of various N-phenyl isocyanates/isothiocyanates. The synthesized analogs were investigated for their antimicrobial activity against two Gram-positive bacteria, three Gram-negative bacteria, and two fungal species. They were also tested for the antimycobacterial activity against Mycobacterium tuberculosis H37Rv. The biological screening data revealed that majority of the compounds have demonstrated noticeable activity (MIC; 6.25–50 μg/mL) against most of the microorganisms. All the synthesized analogs were well characterized through IR, ¹H NMR, ¹³C NMR, and elemental analyses.     

Newer thiazolopyrimidine-based sulfonamides clubbed with benzothiazole moiety: synthesis and biological evaluation

A new class of thiazolopyrimidine-based sulfonamides (5a–j) was synthesized from a parent compound 2-methoxy benzoic acid by multistep reaction in order to find new agents to fight against microbial infections. Substituted thiazolopyrimidines (3a–e) were prepared by cyclocondensation of substituted thiazolidinediones (2a–e) with urea in the presence of acid catalyst P₂O₅. Finally, desired compounds (5a–j) were synthesized from intermediates (4a–e) prepared from compounds (3a–e) by chlorosulfonation followed by condensation with corresponding benzothiazole moiety. The synthesized compounds were characterized by IR, ¹H-NMR, ¹³C-NMR spectral data, and elemental analysis, and were evaluated for in vitro antimicrobial activity against certain bacterial and fungal strains using the broth microdilution method as well as antitubercular activity against H₃₇Rv using Lowenstein–Jensen agar method.     

Synthesis and in vitro antitumor activity of new quinoline, pyrimido[4,5-b]quinoline, [1,2,3]triazino[4,5-b]quinoline, and [1,2,4]triazolo[2′,3′:3,4]pyrimido[6,5-b]quinoline analogs

New series of quinoline, pyrimido[4,5-b]quinoline, [1,2,3]triazino[4,5-b]quinoline, and [1,2,4]triazolo[2′,3′:3,4]pyrimido[6,5-b]quinoline analogs have been synthesized and characterized by analytical and spectrometrical methods (IR, ¹H NMR, ¹³C NMR, MS). Fifteen of the newly synthesized compounds; namely, 3a, b, 4b, 6a, b, 10a–f, and 14a–d were evaluated for their in vitro antitumor activity at the National Cancer Institute (NCI) 60 cell lines panel assay. Compounds 4b and 10f are the most active members in this study, demonstrating significant broad spectrum antitumor activity against most of the tested sub-panel tumor cell lines. The detailed synthesis, spectroscopic, and biological data are described.