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.     

Synthesis of some new indolo[2,3-c]isoquinolinyl pyrazoles, -1,3,4-oxadiazoles and their biological activities

A new series of novel compounds [10-substituted 6H, 7H-indolo[2,3-c]isoquinolin-5-one-6-yl]carbohydrazides (3a–c), 1-[10-substituted 6H, 7H-indolo[2,3-c]isoquinolin-5-one-6-yl]fomyl-, -3′,5′-dimethylpyrazoles (4a–c), -3′,5′-diphenylpyrazoles (5a–c), -3′-methylpyrazol-5′-ones (6a–c) and -1′,3′,4′-oxidiazole-2′-thiones (7a–c) linked to indoloisoquinoline at position-6 through formyl bridge was prepared. The structures of these newly synthesized compounds were confirmed by their spectral studies and elemental analysis. These compounds have been screened for their antimicrobial and antioxidant activities. Compounds 4a, 4b, 5a, 5b, 5c, 6b, 7a, and 7c exhibited the maximum zone of inhibition against A. niger, A. flavus, and A. fumigatus. Compounds 4a, 5a, 5c, 6b, 6c, 7a, and 7b showed good antibacterial activity. Compounds 4b, 4c, 5b, 5c, 6a, 6b, 7a, 7b, and 7c showed good radical scavenging activity compared with standards.     

Synthesis and antimicrobial activity of 5-chloroindoline-2,3-dione derivatives

A series of 3-(5-chloro-2-oxoindolin-3-ylideneamino)-2-arylthiazolidin-4-ones 4a–k and 5-chloro-3-(3-chloro-2-oxo-4-arylazetidin-1-ylimino)indolin-2-ones 5a–k was synthesized. The structures of final compounds were confirmed by analytical (C, H, N) and spectral (FT-IR, ¹H NMR, ¹³C NMR and Mass) data. The synthesized compounds were screened for possible antibacterial and antifungal activity. Compounds 4c, 4f, 4g, 4h, 4i, 4j, 5c, 5f, 5g, 5h, 5i and 5j showed substantially significant activity.     

Synthesis, antitumor activity of 2-amino-4H-benzo[h]chromene derivatives, and structure–activity relationships of the 3- and 4-positions

Several 2-amino-4H-benzo[h]chromenes (3a–i) and (5a–h) were obtained by reaction of 4-chloro-1-naphthol (1) with α-cyanocinnamonitrile (2a–i) or ethyl α-cyanocinnamate derivatives (4a–h), respectively. Structures of these compounds were established on the basis of spectral data. The antitumor activity of the synthesized compounds was investigated in comparison with Vinblastine, Colchicine, and Doxorubicin well-known anticancer drugs, using MTT colorimetric assay. Among them, the compounds 5e, 3c, 5f, b, d, 3d, 5c, a were the most active against MCF-7, 5a against HCT-116 and 5a, 3e, a against HepG-2 as compared with the standard drug Vinblastine, while the compounds 5e, 3c, 5f, b, d, 3d, 5c, a, h, 3i, g, a, e were the most active against MCF-7, 5a, c, e, f, b, 3e, c, g, b, 5d, h, 3d, i, 5g against HCT-116, 5a, 3e, a, 5e, 3c, 5d, c, f, 3b, 5g, 3g, 5h against HepG-2 as compared with the standard drug Colchicine. The structure–activity relationships of the 3- and 4-positions were discussed.     

In-vitro cytotoxicity,antioxidant, bleomycin-dependent DNA damage and immunomodulatory evaluation of 1-(4-acetylphenyl)-3-aryloxypyrrolidine-2, 5-dione based derivatives

A one pot, economical, and efficient synthesis of 1-(4-acetylphenyl)-3-aryloxypyrrolidine-2,5-diones-based derivatives 5a-l have been accomplished in single steps and in satisfactory yields from 1-(4-acetylphenyl)-pyrrole-2,5-diones 3 and phenols 4a–l. All the compounds were characterized by physical, spectroscopic, and elemental analysis. The selection of the bioassays was based on proving the drug receptor binding concept. Compounds 5g, 5k, 5h, 5i, 5a, and 5f showed the highest inhibitory antioxidant activity using ABTS methods. Compounds 5k, 5g, 5c, 5h, 5b, 5d, 5f, and 5j manifested the best protective effect against DNA damage induced by bleomycin. Moreover, an in-vitro cytotoxic activity evaluation of all synthesized compounds was against four cancer cell lines using 5-Fluorouracil as a standard anticancer drug.     

Synthesis, anti-inflammatory, and cytotoxicity evaluation of 9,10-dihydroanthracene-9,10-α,β-succinimide and bis-succinimide derivatives

9,10-Dihydroanthracene-9,10-α,β-succinimide derivatives 4a–e and bis-succinimide derivatives 6a–e have been synthesized by grinding 9,10-dihydroanthracene-9,10-α,β-succinic anhydride 2 with various mono 3a–e and diamines 5a–e in quantitative yields. All the target compounds were fully characterized by spectrometric and spectroscopic means. Compounds 4a–e, 6a–e and recently reported compounds 4f–p were screened for anti-inflammatory and for cytotoxicity against five human cancer cell lines: T47D, NCI H-522, HCT-15, PA1, and HepG-2. Compounds 4e, 4i, 4j, and 4p exhibited good anti-inflammatory activity and compounds with interesting cytotoxic profile were 4c, 6e (T47D); 4e, 4o (NCI H-522); 4n (HCT-15); 4e, 4h, 4o (PA1); and 4a, 4e, 4f, 4i, 4o (HepG-2).     

Synthesis and antitumor screening of new series of pyrimido-[4,5-b]quinolines and [1,2,4]triazolo[2′,3′:3,4]pyrimido[6,5-b]quinolines

New series of pyrimido[4,5-b]quinolines and [1,2,4]triazolo[2′,3′:3,4]pyrimido[6,5-b]quinolines have been synthesized. Compounds 4a, 4e, 4f, 4h, 5b, 5d, 6a, 6d, 6e, 8c, 8d, 10c–e, 10h, 11a, 11b, and 12a were tested for in vitro antitumor activity against human breast carcinoma (MCF-7) cell line, where compound 8d was found to be the most active member with IC₅₀ value of 3.62 μM. The DNA-binding affinity for the same compounds showed that compounds 8d and 10d exhibited the highest affinity to DNA. The detailed synthesis, spectroscopic, and biological data are reported.     

Synthesis, antimicrobial, and antioxidant activities of some new indole analogues containing pyrimidine and fused pyrimidine systems

To examine new leads with potential antimicrobial and antioxidant activities, a new series of tetrahydropyrimidines (2a–c, 3a–c and 4a–c), pyrazolo[3,4-d]pyrimidines (5a–c), and ditetrazolo[1,5-a;1′,5′-c]pyrimidines (6a–c) were synthesized in this study using appropriate synthetic routes. The newly synthesized compounds have been tested for their antimicrobial and antioxidant activities against DPPH stable free radical. In the case of antibacterial activity, compounds 2a, 6a, and 6c exhibited the maximum zone of inhibition against Staphylococcus aureus; compound 6c exhibited maximum zone of inhibition against Pseudomonas aeruginosa; and compound 2a showed maximum inhibitory growth against Klebsiella pneumonia. While in the case of antifungal activities, compound 5a showed good zone of inhibition against Aspergillus oryzae, compounds 2b and 6a exhibited maximum zone of inhibition against Aspergillus niger. In case of antioxidant activities, compound 2a showed the highest DPPH radical scavenging activity.     

Synthesis, anti-inflammatory and anticancer activity evaluation of some mono- and bis-Schiff’s bases

Several mono-Schiff’s bases (3a–i) and bis-Schiff’s bases (5a–f) were synthesized using microwave irradiation technique (3a–h, 5a–c) and by simply grinding at room temperature for a few minutes (3i, 5d–f). All these compounds were characterized by spectroscopic means and elemental analysis. They were screened for anti-inflammatory and anticancer activities (against five human cancer cell lines). Compound 5f exhibited good anti-inflammatory and compounds 3f, 5a–f exhibited good anticancer activity.     

Synthesis of β-amino carbonyl derivatives of coumarin and benzofuran and evaluation of their biological activity

A series of β-amino carbonyl compounds containing coumarin (4a–h) and benzofuran (6a–i) moieties was synthesized by a three component Mannich reaction of 3-acetyl-2H-chromen-2-one (1) or 1-(1-benzofuran-2-yl) ethanone (5) with p-substituted aromatic aldehydes (2a–g) and aromatic amines (3a–b) in the presence of cerric ammonium nitrate as a catalyst. The newly synthesized compounds were screened for antimicrobial and antioxidant activities. Compounds 4b, 4e, 4f, 6f, 6g, and 6i showed microbial inhibition with minimal inhibition concentration ranging between 0.040 and 0.500 mg/mL, compounds 4b, 4c, 6c, 6e, and 6i showed promising free radical scavenging activity and compounds 4b, 4f, 6c, 6d, and 6h showed good chelating ability with Fe²⁺ ions. The synthesized compounds were studied for docking on the enzyme, glucosamine-6-phosphate synthase to predict the binding affinity and orientation at the active site of the receptor.     

5-phenyl-1-benzofuran-2-yl derivatives: synthesis, antimicrobial, and antioxidant activity

Previously unknown biphenyl containing 5-phenyl-1-benzofuran-2-yl derivatives; methanones (2a–i), tertiary alcohols (3a–l), and carbinols (4a–f) were synthesized and evaluated for their antimicrobial and antioxidant activities to study the effect of functionalization at the carbonyl carbon and substitution at biphenyl ring on these activities. The introduction of hydroxyl group at carbonyl carbon enhanced the antioxidant property (3a, 3g, 3h, 4a, and 4b), while antimicrobial activity decreased; the carbinol and tertiary alcohols corresponding to methanone 2a and 2b showed no antimicrobial activity. Biphenyl methanones 1, 2a, 2f, and 2g exhibited antimicrobial activity with minimal inhibitory concentration ranging between 0.001 and 0.500 mg/mL, tertiary alcohols 3a, 3g, and 3h and carbinols 4a and 4b exhibited the promising antioxidant property. The mode of action of these active compounds was carried out by docking of receptor GlcN6P synthase with newly synthesized candidate ligands 1, 2a, 2e, 2f, 2g, 2h, 3a, 3g, 3h, 4c, and 4d.     

Oxygenated chalcones and bischalcones as a new class of inhibitors of DNA topoisomerase II of malarial parasites

The DNA topoisomerase (topo) II of chloroquine-sensitive and chloroquine-resistant strains of the rodent malaria parasite P. berghei were utilized as a target for testing of antimalarial compounds. Compounds belonging to the bischalcone and chalcone series significantly inhibited enzyme activity and percentage parasitaemia of chloroquine-sensitive and chloroquine-resistant strains of P. berghei. Compounds 1a, 1b, 2a, 2b, and 2c showed 100% inhibition while compounds 2h and 2i showed 60% and 63% inhibition of topoisomerase II activity of the chloroquine-sensitive strain, respectively. Compounds 2a, 2b, and 2d significantly inhibited the topo II activity of chloroquine-resistant strain. Compounds 2g and 2e specifically inhibited the topo II activity of the chloroquine-resistant strain of P. berghei with no effect on the chloroquine-sensitive strain. The in vitro topo II inhibition by chalcone and bischalcone analogs can be correlated with their in vivo antimalarial activity, as compounds 2c and 2h inhibited both in vitro activity of topo II and in vivo parasitaemia of the chloroquine-sensitive strain of P. berghei. In the chloroquine-resistant strain, compounds 2c, 2e, 2g, and 2i inhibited activity against both in vitro topo II and parasitaemia in vivo. The significant inhibition of topo II in the chloroquine-resistant strain by some of the analogs suggests the utilization of these structures for the synthesis of compounds active against chloroquine-resistant malarial parasites.     

Synthesis, antitumor activity, and structure–activity relationship of some 4H-pyrano[3,2-h]quinoline and 7H-pyrimido[4′,5′:6,5]pyrano[3,2-h]quinoline derivatives

Several 4H-pyrano[3,2-h]quinoline (3a–d, 4a, 7a,b, 9a–c, 10a,b, 11a,b, and 13a–c) and 7H-pyrimido[4′,5′:6,5]pyrano[3,2-h]quinoline derivatives (8a–c) were obtained by treatment of 8-hydroxyquinoline (1a) and 8-hydroxy-2-methylquinoline (1b) with α-cyano-p-chloro/bromocinnamonitrile (2a,b) or 4H-pyrano[3,2-h]quinoline derivatives (3a,c,d) with different electrophilic reagents followed by nucleophilic reagents. Structures of these compounds were established on the basis of spectral data. The antitumor activity of the synthesized compounds was investigated in comparison with Vinblastine. Among them, compounds 3c,d, 4a, 8b, 9b,c, 11a,b, and 13a,c inhibited the growth of cancer cells compared to Vinblastine. The structure–activity relationships were discussed.     

Synthesis and antitumor properties of novel alizarin analogs

Series of novel hybrids of alizarin and diamide scaffold (3a–3h, 7a–7h) were designed and synthesized. In vitro antitumor activities of all compounds against HepG-2, CNE, Spca-2, Hct-116, and MGC-803 cell lines were evaluated, and employing standard MTT assay compared with commercial anticancer drug 5-fluorouracil (5-FU). Compounds 7b, 7c, 7d, and 7e showed relatively high cytotoxicity. Especially, compound 7c exhibited the best cytotoxicity against CNE cells with IC₅₀ 9.08 µM, which was even stronger than that of 5-FU. All the synthesized compounds exhibited low cytotoxicity against HUVEC cells. The action mechanism of representative compound 7c was preliminarily investigated by flow cytometry, which indicated that the compound can induce cell apoptosis in CNE cells. Cell cycle analysis showed that compound 7c mainly arrested CNE cells in G1 stage. In addition, the binding properties of a model analog 7c to DNA were investigated by different methods (fluorescence, CD spectroscopy), and the results indicated that 7c showed a moderate preference for binding ct-DNA.     

Synthesis and antimicrobial screening of 4-thiazolidinone and 2-azetidinone derivatives of piperazine

The Schiff’s bases 3a–3h were synthesized by reacting substituted/unsubstituted aromatic aldehydes 2a–2h with 1-(2-aminoethyl)-piperazine 1. A series of novel aryl-3-(2-piperazin-1-ylethyl)-1,3-thiazolidin-4-one 4a–4h and 3-chloro-1-{2-[4-(chloroacetyl)piperazin-1-yl]ethyl}-4-arylazetidin-2-one 5a–5h were synthesized from the Schiff’s bases of 1-(2-aminoethyl)-piperazine 3a–3h. The structures of synthesized compounds were confirmed by analytical (C, H, and N) and spectral (FT-IR, ¹H NMR, ¹³C NMR, and Mass) data. The compounds 4a–4h and 5a–5h were screened for antimicrobial activity. The compounds 4a, 4d, 4f, 4g, 5a, 5d, 5f, and 5g exhibited substantially significant antibacterial as well as antifungal activity.     

Synthesis and characterization of flurbiprofen hydrazide derivatives as potential anti-HCV, anticancer and antimicrobial agents

A novel series of new flurbiprofen hydrazide derivatives 2-(2-fluorobiphenyl-4-yl)-N′-[(substituted phenyl/5-nitro-2-furyl)methylene]propanehydrazide (3a–k), 2-(2-fluorobiphenyl-4-yl)-N-(2-substituted-4-oxo-1,3-thiazolidine-3-yl)propanamide (4a–b, 4d–k), 2-[2-(2-fluorobiphenyl-4-yl) propanoyl]-N-substituted hydrazinecarbothioamide (5a–h) and 2-(2-fluorobiphenyl-4-yl)-N′-[(3-methyl-4-oxo-1,3-thiazolidin-2-ylidene]propanehydrazide (6a–b, 6e and 6g) has been synthesized in this study. All synthesized compounds were screened for antimicrobial activity against various bacterial and fungal strains. Additionally, compounds were evaluated for the ability to inhibit Hepatitis C virus NS5B polymerase. The most active 4-thiazolidinone compound was 4k (SGK119) with 67.0 % and thiosemicarbazide compound was 5d (SGK123) with 69.50 % inhibition at 200 μM against hepatitis C virus NS5B RNA polymerase. Anticancer activity of the selected compounds (3i, 3j, 3h, 4d, 4i and 6b) was determined at a single dose towards the full panel of 60 human cancer cell lines by the National Cancer Institute (NCI). 2-(2-Fluoro-4-biphenylyl)-N-[2-[4-(trifluoromethyl)phenyl]-4-oxo-1,3-thiazolidine-3-yl]propanamide 4d, containing thiazolidinone ring, demonstrated the most marked effect with 20.80 % growth percent on leukaemia cancer cell line SR at 10^?5 M. The results demonstrated that none of the compounds tested have anticandidal and antifungal activities, but two of them (4a and 4i) showed antibacterial inhibition against Micrococcus luteus, and Staphylococcus cohnii and Staphylococcus aureus, respectively.     

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 biological evaluation of novel curcumin analogues as anti-inflammatory, anti-cancer and anti-oxidant agents

A series of novel curcumin analogues 5a–m were synthesized by Claisen-Schmidt condensation of various aromatic and heteroaromatic amides of 3-aminoactophenones 4a–m with 3-bromo-2,4,6-trimethoxybenzaldehyde and characterized by IR, ¹H NMR and mass spectroscopic analysis and were evaluated for anti-inflammatory, anti-cancer and anti-oxidant activity. Out of the 13 synthesized compounds, compounds 5f, 5j and 5m were excellent inhibitors of TNF-α and IL-6. Compounds 5c, 5e, 5b and 5d showed potent COX-2 inhibition, compounds 5d and 5f have shown good trypsin inhibition and compounds 5e, 5g and 5c exhibited excellent β-glucuronidase inhibition. Compounds 5l and 5m showed potent anti-cancer activity against selected five human cancer cell lines. All the compounds exhibited moderate free radical scavenging activity, while compounds 5a and 5m were excellent OH radical scavengers.     

Synthesis of new olefin chalcone derivatives as antitumor, antioxidant and antimicrobial agents

Chalcone is a unique template that is associated with several biological activities. Claisen–Schmidt condensation of olefin aldehyde 3 and various mono, disubstituted and heterocyclic acetophenones afforded novel olefin chalcones. Synthesized compounds were subjected for ADME prediction by computational method which revealed that these molecules can be considered as a potential drug. Out of the 21 compounds screened, compounds 5u, 5g, 5c and 5e have shown significant cytotoxicity against Hep 3BPN 7, compounds 5j, 5i, 5n and 5o showed good cytotoxicity against HL 60 P 58. Compounds 5f, 5c, 5e and 5b showed potent cytotoxicity against Hela B 75. Antioxidant activity was assessed using three methods, namely, 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical scavenging and ferric reducing antioxidant power (FRAP). The result shows that all these compounds possess significant antioxidant activity. Compounds 5k, 5s, 5a and 5c showed promising antibacterial activity. Compounds 5k, 5u and 5f could be considered as chemopreventive agents.     

Synthesis and biological evaluation of amino acid-linked 1,2,3-bistriazole conjugates as potential antimicrobial agents

A small library of amino acid-linked 1,4-disubstituted 1,2,3-bistriazole conjugates has been synthesized from the N-protected l-amino acids propargyl esters through one-pot click reaction. All the newly synthesized compounds were tested in vitro for antimicrobial activity against Gram-positive (Staphylococcus aureus, Bacillus subtilis), Gram-negative (Escherichia coli) bacteria and fungi (Candida albicans, Aspergillus niger). The antibacterial evaluation data indicated that compounds 3c, 3h, 5a, 5b, 5c, 5d, 5e, 5g, and 5h exhibited comparable activity to standard ciprofloxacin. However, the bistriazoles 3b, 3c, 3e, 3f, and 3g showed good antifungal activity than others against both fungi. Further, docking simulation of the two most active compounds 5c against S. aureus tyrosyl tRNA synthetase and 5h into E. coli topoisomerase II DNA Gyrase B, respectively, was also performed.