Synthesis of novel 3-(1-(1-substituted piperidin-4-yl)-1H-1,2,3-triazol-4-yl)-1,2,4-oxadiazol-5(4H)-one as antifungal agents

A novel series of 1,2,3 triazole compounds possessing 1,2,4 oxadiazole ring were efficiently synthesized. Synthesized compounds were evaluated for their in vitro antifungal activities using standard cup plate method. SAR for the series has been developed by comparing their MIC values with miconazole and fluconazole. Compound 11a from the series was more potent than miconazole against Candida albicans (MIC-20) and Aspergillus flavus (MIC-10) whereas equipotent with miconazole against Fusarium oxysporum (MIC-25) and Aspergillus niger (MIC-12.5). Also compound 11h was more potent than miconazole against Candida albicans (MIC-20) and Aspergillus niger (MIC-10) and equipotent with miconazole against Fusarium oxysporum. Compound 11h was equipotent with fluconazole against Aspergillus niger (MIC-10).     

Design and synthesis of 1-(benzothiazol-5-yl)-1H-1,2,4-triazol-5-ones as protoporphyrinogen oxidase inhibitors

Protoporphyrinogen oxidase (PPO, E.C. 1.3.3.4) is the action target for several structurally diverse herbicides. A series of novel 4-(difluoromethyl)-1-(6-halo-2-substituted-benzothiazol-5-yl)-3-methyl-1H-1,2,4-triazol-5(4H)-ones 2a–z were designed and synthesized via the ring-closure of two ortho-substituents. The in vitro bioassay results indicated that the 26 newly synthesized compounds exhibited good PPO inhibition effects with K_i values ranging from 0.06 to 17.79 μM. Compound 2e, ethyl 2-{[5-(4-(difluoromethyl)-3-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-6-fluorobenzo-thiazol-2-yl]thio}acetate, was the most potent inhibitor with K_i value of 0.06 μM against mtPPO, comparable to (K_i = 0.03 μM) sulfentrazone. Further green house assays showed that compound 2f (K_i = 0.24 μM, mtPPO), ethyl 2-{[5-(4-(difluoromethyl)-3-methyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl)-6-fluorobenzothiazol-2-yl]thio}propanoate, showed the most promising post-emergence herbicidal activity with broad spectrum even at concentrations as low as 37.5 g ai/ha. Soybean exhibited tolerance to compound 2f at the dosages of 150 g ai/ha, whereas they are susceptible to sulfentrazone even at 75 g ai/ha. Thus, compound 2f might be a potential candidate as a new herbicide for soybean fields.     

Synthesis and Fungicidal Activity of 5-Aryl-1-(aryloxyacetyl)-3-(tert-butyl or phenyl)-4-(1H-1,2,4-triazol-1-yl)-4,5-Dihydropyrazole

A series of novel 5-aryl-1-(aryloxyacetyl)-3-(tert-butyl or phenyl)-4-(1H-1,2,4-triazol-1-yl)-4,5-dihydropyrazole 3a-3n were synthesized by the annulation of 2-aryloxyacetohydrazides with 3-aryl-1-t-butyl(or phenyl)-2-(1H-1,2,4-triazol-1-yl)prop-2-en-1-ones(1)in the presence of a catalytic amount of acetic acid.Compounds 2 were obtained by the Knoevenagel reactions of 1-t-butyl(or phenyl)-2-(1H-1,2,4-triazol-1-yl)ethanone(2)with aromatic aldehydes in the presence of piperidine.Their structures were confirmed by IR,1H-NMR,ESIMS,and elemental analyses.The preliminary bioassay indicated that some compounds displayed moderate to excellent fungicidal activity.For example,compounds 31,3m,and 3n possessed100%inhibition against Cercospora arachidicola Hori at the concentration of 50 mg/L.     

Synthesis and evaluation of 3-(benzylthio)-5-(1H-indol-3-yl)-1,2,4-triazol-4-amines as Bcl-2 inhibitory anticancer agents

A series of substituted 3-(benzylthio)-5-(1H-indol-3-yl)-4H-1,2,4-triazol-4-amines has been synthesised and tested in vitro as potential pro-apoptotic Bcl-2-inhibitory anticancer agents. Synthesis of the target compounds was readily accomplished in good yields through a cyclisation reaction between indole-3-carboxylic acid hydrazide and carbon disulfide under basic conditions, followed by S-benzylation. Active compounds, such as the nitrobenzyl analogue 6c, were found to exhibit sub-micromolar IC₅₀ values in Bcl-2 expressing human cancer cell lines. Molecular modelling and ELISA studies further implicated anti-apoptotic Bcl-2 as a candidate molecular target underpinning anticancer activity.     

Synthesis and in vitro activity of 1-(2,3-dichlorophenyl)-N-(pyridin-3-ylmethyl)-1H-1,2,4-triazol-5-amine and 4-(2,3-dichlorophenyl)-N-(pyridin-3-ylmethyl)-4H-1,2,4-triazol-3-amine P2X7 antagonists

A novel series of aminotriazole-based P2X(7) antagonists was synthesized, and their structure-activity relationships (SAR) were investigated for activity at both human and rat P2X(7) receptors. Most compounds showed greater potency at the human receptor although several analogs were discovered with potent activity (pIC(50) > or = 7.5) at both human and rat P2X(7).     

Synthesis of novel pyrazolic analogues of chalcones and their 3-aryl-4-(3-aryl-4,5-dihydro-1H-pyrazol-5-yl)-1-phenyl-1H-pyrazole derivatives as potential antitumor agents

Novel (E)-1-aryl-3-(3-aryl-1-phenyl-1H-pyrazol-4-yl)prop-2-en-1-ones 5/6 (pyrazolic chalcones) were synthesized from a Claisen–Schmidt reaction of 3-aryl-1-phenylpyrazol-4-carboxaldehydes 4 with several acetophenone derivatives 1. Subsequently, the microwave-assisted cyclocondensation reaction of chalcones 5/6 with hydrazine afforded the new racemic 3-aryl-4-(3-aryl-4,5-dihydro-1H-pyrazol-5-yl)-1-phenyl-1H-pyrazoles 7 or their N-acetyl derivatives 8 and 9 when reactions where carried out in DMF or acetic acid, respectively. Several of these compounds were screened by the US National Cancer Institute (NCI) for their ability to inhibit 60 different human tumor cell lines, where 5c and 9g showed remarkable activity mainly against leukemia (K-562 and SR), renal cancer (UO-31) and non-small cell lung cancer (HOP-92) cell lines, with the most important GI₅₀ values ranging from 0.04 to 11.4 μM, from the in vitro assays.     

Synthesis and biological evaluation of 4-(1,2,3-triazol-1-yl)coumarin derivatives as potential antitumor agents

In this research, a series of 4-(1,2,3-triazol-1-yl)coumarin conjugates were synthesized and their anticancer activities were evaluated in vitro against three human cancer cell lines, including human breast carcinoma MCF-7 cell, colon carcinoma SW480 cell and lung carcinoma A549 cell. To increase the biological potency, structural optimization campaign was conducted focusing on the C-4 position of 1,2,3-triazole and the C-6, C-7 positions of coumarin. In addition, to further evaluate the role of 1,2,3-triazole and coumarin for antiproliferative activity, 9 compounds possessing 4-(piperazin-1-yl)coumarin framework and 3 derivatives baring quinoline core were also synthesized. By MTT assay in vitro, most of the compounds display attractive antitumor activities, especially 23. Further flow cytometry assays demonstrate that compound 23 exerts the antiproliferative role through arresting G₂/M cell-cycle and inducing apoptosis.     

Enantioselective synthesis and cytotoxic evaluation of 4,5-dihydro-5-[aryl(hydroxy)methyl]-3-methylidenefuran-2(3H)-ones

A series of enantiomerically enriched 4,5-dihydro-5-[aryl(hydroxy)methyl]-3-methylidenefuran-2(3H)-ones (8) were synthesized by means of asymmetric Sharpless dihydroxylation of the 2-phosphorylated 5-aryl-pent-4-enoic acids 13, followed by Horner-Wadsworth-Emmons reaction of the resulting furanones 15 (Scheme 2). An enantiomeric excess (ee) of 20-95% was achieved for compounds 8, and their absolute configurations were determined by the Mosher ester method. Cytotoxic evaluation against L-1210 and HL-60 leukemia cell lines revealed that the target compounds 8 are active in the micromolar concentration range (Table 2). Thereby, significant differences in activity between the corresponding enantiomers were observed for the HL-60 cell line.     

Synthesis of novel 3-(alkylcarbamoyl)-2-aryl-1,2-dihydro-6,7-(methylenedioxy)-3H-quinazolin-4-ones as anticonvulsant agents

A series of 3-(alkylcarbamoyl)-2-aryl-1,2-dihydro-6,7-(methylenedioxy)-3H-quinazolin-4-ones, compounds 3-6, were synthesized, and screened as anticonvulsant agents in DBA/2 mice against sound-induced seizure (Table). The new compounds were found to display anticonvulsant properties inferior to those of the known dehydro congeners 1 and 2. The binding affinities of 1-6 at the AMPA and NMDA receptors were also evaluated.     

Synthesis of 3-(1-alkyl/aminoalkyl-3-vinyl-piperidin-4-yl)-1-(quinolin-4-yl)-propan-1-ones and their 2-methylene derivatives as potential spermicidal and microbicidal agents

A series of twenty two derivatives of 3-(1-alkyl/aminoalkyl-3-vinyl-piperidin-4-yl)-1-(quinolin-4-yl)-propan-1-one and their 2-methylene derivatives were synthesized from naturally abundant cinchonine (I). Tartarate salts of these compounds were prepared and evaluated for spermicidal activity. The most active compounds (24, 27, 34, 36, and 38) showing potent spermicidal activity were further evaluated against different strains of Trichomonas vaginalis, for antimicrobial activity, in HeLa cell lines for cytotoxicity and against Lactobacillus jensenii for eco-safety. The tartarate of 3-(1-pentyl-3-vinyl-piperidin-4-yl)-1-(quinolin-4-yl)-propan-1-one (27) was found to be more active than N-9 in spermicidal activity.     

Design, synthesis, and evaluation of 1-(N-benzylamino)-2-phenyl-3-(1H-1,2,4-triazol-1-yl)propan-2-ols as antifungal agents

A series of 1-(N-benzylamino)-2-phenyl-3-(1H-1,2,4-triazol-1-yl)propan-2-ols 6a-c, 7a-c, 8a, and 9a were prepared in five steps and evaluated for their antifungal activity. The most active compound 7b was docked into a home-made 3D model of the targeted enzyme confirming the importance of Tyr118, His377, and Ser378 residues in its binding mode.     

Experimental and DFT computational studies on 5-benzyl-4-(3,4-dimethoxyphenethyl)-2H-1,2,4-triazol-3(4H)-one

The triazole compound, 5-benzyl-4-(3,4-dimethoxyphenethyl)-2H-1,2,4-triazol-3(4H)-one, has been synthesized and characterized by ¹H-NMR, ¹³C-NMR, IR, and X-ray single-crystal determination. The compound crystallizes in the monoclinic space group P2₁ with a?=?11.8844(3) Å, b?=?17.5087(4) Å, c?=?17.3648(6) Å, β?=?99.990(2)? and Z?=?8. In addition to the molecular geometry from X-ray experiment, the molecular geometry, vibrational frequencies and gauge including atomic orbital (GIAO) ¹H- and ¹³C-NMR chemical shift values of the title compound in the ground state have been calculated using the density functional method (B3LYP) with 6-31G(d,p) basis set. The calculated results show that the optimized geometries can well reproduce the crystal structure and the theoretical vibrational frequencies and chemical shift values show good agreement with experimental ones. Besides, molecular electrostatic potential (MEP), natural bond orbital (NBO), and frontier molecular orbitals (FMO) analysis of the title compound were performed by the B3LYP/6-31G(d,p) method.     

Synthesis and structure-activity relationships of 3-substituted 1,4-dihydro-4-oxo-1-(2-thiazolyl)-1,8-naphthyridines as novel antitumor agents

In order to obtain clinically useful antitumor agent, we have designed and synthesized various 3-substituted 1,4-dihydro-4-oxo-1-(2-thiazolyl)-1,8-naphthyridines, and evaluated their cytotoxic activity. The series of novel 3-substituted derivatives synthesized in this study showed good antitumor activity against murine P388 leukemia. Particularly, the 3-formyl 1,8-naphthyridine displayed an antitumor activity equal to that of the 3-carboxy 1,8-naphthyridine against murine and human tumor cell lines as well as in vivo test for mouse leukemia. These results demonstrate that the carboxy group at the C-3 position of 1,8-naphthyridine ring is not essential for antitumor activity. In addition, the trend of cytotoxic activity for the 3-substituted 1,8-naphthyridines was different from that of antibacterial activity.     

Synthesis and biological evaluation of (4H-1,2,4-triazol-4-yl)isoquinoline derivatives as selective glycine transporter 1 inhibitors

To identify novel glycine transporter 1(GlyT1) inhibitors with greater selectivity relative to GlyT2 and improved aqueous solubility, we synthesized a series of 4H-1,2,4-triazole derivatives with heteroaromatic rings at the 4-position and investigated their structure-activity relationships. Replacement of the 2-fluorophenyl group of lead compound 5 with various aromatic groups led to the identification of 5-(3-biphenyl-4-yl-5-ethyl-4H-1,2,4-triazol-4-yl)isoquinoline (15) with 38-fold selectivity between GlyT1 and GlyT2. 15 also showed improved aqueous solubility and in vivo efficacy on (+)-HA966-induced hyperlocomotion in mice over the lead compound.     

Synthesis of 5-(4-hydroxy-3-methylphenyl)-5-(substituted phenyl)-4, 5-dihydro-1H-1-pyrazolyl-4-pyridylmethanone derivatives with anti-viral activity

A series of N¹-nicotinoyl-3- (4-hydroxy-3-methyl phenyl)-5-(substituted phenyl)-2-pyrazolines were synthesized by the reaction between isoniazid (INH) and chalcones and were tested for their in vitro anti-viral activity. Among the compounds, the electron withdrawing group substituted analogues 5-(4-chlorophenyl)-3-(4-hydroxy-3-methylphenyl)-4, 5-dihydro-1H-1-pyrazolyl-4-pyridylmethanone (4b), 5-(2-chlorophenyl)-3-(4-hydroxy-3-methylphenyl)-4,5-dihydro-1H-1-pyrazolyl-4-pyridylmethanone (4i), 5-(4-fluorophenyl)-3-(4-hydroxy-3-methylphenyl)-4,5-dihydro-1H-1-pyrazolyl-4-pyridylmethanone (4h) and 5-(2,6-dichlorophenyl)-3-(4-hydroxy-3-methylphenyl)-4,5-dihydro-1H-1-pyrazolyl-4-pyridyl methanone (4j) were the most promising and the halogeno function appeared to be essential for antiviral activity.     

Synthesis of 5-(4-hydroxy-3-methylphenyl) -5- (substituted phenyl)-4, 5-dihydro-1H-1-pyrazolyl-4-pyridylmethanone derivatives with anti-viral activity

A series of N1-nicotinoyl-3- (4-hydroxy-3-methyl phenyl)-5-(substituted phenyl)-2-pyrazolines were synthesized by the reaction between isoniazid (INH) and chalcones and were tested for their in vitro anti-viral activity. Among the compounds, the electron withdrawing group substituted analogues 5-(4-chlorophenyl)-3-(4-hydroxy-3-methylphenyl)-4, 5-dihydro-1H-1- pyrazolyl-4-pyridylmethanone (4b), 5-(2-chlorophenyl)-3-(4-hydroxy-3-methylphenyl)-4,5-dihydro-1H-1-pyrazolyl-4-pyri- dylmethanone (4i), 5-(4-fluorophenyl)-3-(4-hydroxy-3-methylphenyl)-4,5-dihydro- 1H-1-pyrazolyl-4-pyridylmethanone (4h) and 5-(2,6-dichlorophenyl)-3-(4-hydroxy-3-methylphenyl)-4,5-dihydro- 1H-1-pyrazolyl-4-pyridyl methanone (4j) were the most promising and the halogeno function appeared to be essential for antiviral activity.     

Impact of tautomery of 3-(4H-1,2,4-triazol-3-ylthio)-N-phenylpropanamide on the COX-1 inhibitory mechanism

Earlier, we have reported the synthesis and anti-inflammatory evaluation of different 3-(4H-1,2,4-triazol-3-ylthio)-N-substituted propanamide. In this article, we are reporting the various tautomeric forms of the most active anti-inflammatory compound, 3-(4H-1,2,4-triazol-3-ylthio)-N-phenylpropanamide (6a) and their virtual screening by molecular docking using six principle tautomeric forms. Docking analysis suggested that compound 3-(4H-1,2,4-triazol-3-ylthio)-N-phenylpropanamide (6a) bound with COX-1 selectively and drug receptor complex was stabilized by tautomerism. Noticeably, hydroxy group formed by tautomerism appreciably improve the drug receptor interactions. It was also supervised that the compound 3-(4H-1,2,4-triazol-3-ylthio)-N-phenylpropanamide (6a) docked near the gate of COX-1 active site and might block the conversion of arachidonic acid to prostaglandin (PG) H2 in the active site of COXs. Moreover, we have carried out receptor based electrostatic analysis to clarify the electronic, steric and hydrophobic field requirement of 3-(4H-1,2,4-triazol-3-ylthio)-N-phenylpropanamide (6a) to interact with COX -1 receptor.     

Design and synthesis of 2-(3-alkylaminophenyl)-6-(pyrrolidin-1-yl)quinolin-4-ones as potent antitumor agents

2-(3-Alkylaminophenyl)-6-(pyrrolidin-1-yl)quinolin-4-ones 1–3 were synthesized and screened for anti-proliferative activity against three human cancer cell lines, as well as the normal cell line Detroit 551. All of the synthesized target compounds 1–3 demonstrated potent cytotoxic activity against the cancer cell lines, but weak inhibitory activity toward the normal cell line. 2-(3-Methyl aminophenyl)-6-(pyrrolidin-1-yl)quinolin-4-one (1), one of the potent compounds in vitro, was also tested in an in vivo Hep3B xenograft nude mice model, and its significant anticancer activity was reconfirmed. Therefore, compound 1 merits further investigation as an antitumor clinical trial candidate and potential anticancer agent.     

Synthesis,antibacterial and antifungal activities of 3-(1,2,4-triazol-3-yl)-4-thiazolidinones

A new series of 3-(1,2,4-triazol-3-yl)-4-thiazolidinone derivatives has been synthesized by the reaction of Schiff bases of 3-amino-1,2,4-triazoles with mercaptoacetic acid and 2-mercaptopropionic acid. Their antibacterial and antifungal activities were evaluated against S. aureus, S. epidermidis, C. albicans and C. glabrata