Synthesis and biological evaluation of 1-(3-chloro-2-oxo-4-phenylazetidin-1-yl)-3-(2-oxo-2-(10H-phenothiazin-10-yl)ethyl)urea derivatives

A new series of eleven novel 1-(3-chloro-2-oxo-4-phenylazetidin-1yl)-3-(2-oxo-2-(10H-phenothiazin-10-yl)ethyl)urea derivatives were synthesized by cyclocondensation of various Schiff bases of phenothiazine with chloroacetyl chloride in the presence of triethylamine. Various Schiff bases of phenothiazine were synthesized by condensation of 4-(2-oxo-2-(10H-phenothiazin-10-yl)ethyl semicarbazide with various aryl aldehydes. The synthesized compounds were characterized by IR, MASS and ¹H NMR spectral data and evaluated for in vitro antimicrobial, antitubercular, antioxidant and anticancer activities by disc diffusion method, MIC method, REMA, DPPH, FRAP and MTT assay method, respectively. All synthesized compounds showed moderate-to-significant anti-bacterial and anti-fungal activity and compound 4d, 4g, 4h and 4k showed good antioxidant activity with EC₅₀ value of 55, 57, 56 and 47 μg/ml tested by DPPH method. The compounds 4j at a concentration of 10 μg/ml showed inhibition against the growth of Mycobacterium tuberculosis and 4f showed significant activity against human cervical cancer cell line with IC₅₀ values of 18.26 μM.     

Synthesis, in vitro antimicrobial, antiproliferative, and QSAR studies of N-(substituted phenyl)-2/4-(1H-indol-3-ylazo)-benzamides

In this study, N-(substituted phenyl)-2/4-(1H-indol-3-ylazo)-benzamides (1–26) were synthesized and screened for their in vitro antibacterial (Gram positive; S. aureus, B. subtilis and Gram negative; E. coli) and antifungal (C. albicans and A. niger) activities. The antimicrobial activity results indicated that compound, 4-(1H-indol-3-ylazo)-N-(4-nitro-phenyl)-benzamide (12, pMIC_am = 1.61) was the most potent. In general, it was found that the synthesized compounds were bacteriostatic/fungistatic in action except fungicidal for A. niger. The synthesized compounds were also evaluated for their antiproliferative activity against human colon cancer (HCT116), murine leukemia (P388), and breast cancer (MCF7) cell lines. The antiproliferative study results demonstrated 4-(1H-indol-3-ylazo)-N-p-tolyl-benzamide (2, IC₅₀ = 0.0003 μM/mL) and 4-(1H-indol-3-ylazo)-N-p-tolyl-benzamide (21, 0.0003 μM/mL) as lead compounds for the development of novel antiproliferative agents. The QSAR studies indicated the importance of topological parameters, Kier’s alpha second-order shape indice (κα₂) and Wiener index (W) in describing the antimicrobial activity of the synthesized compounds.     

Synthesis and antimicrobial activity of some (3-phenyl-5-(1-phenyl-3-aryl-1H-pyrazol-4-yl)-4,5-dihydro-1H-pyrazol-1-yl)(pyridin-4-yl)methanones: new derivatives of 1,3,5-trisubstituted pyrazolines

A series of (3-phenyl-5-(1-phenyl-3-aryl-1H-pyrazol-4-yl)-4,5-dihydro-1H-pyrazol-1-yl)(pyridin-4-yl)methanones was synthesized by condensing suitably substituted chalcones, i.e., 3-(3-aryl-1-phenyl-1H-pyrazol-4-yl)-1-phenylprop-2-en-1-ones, and isoniazid in acetic acid. The structure of newly synthesized compounds has been established on the basis of analytical and spectral data. The new compounds were screened for antimicrobial activity and most of them showed good activity comparable with that of standard drugs ciprofloxacin and fluconazole. Compounds containing methoxy group showed high antimicrobial activity.     

Synthesis of novel 2-phenyl-3-[2-(substituted amino) ethylamino] quinazolin-4(3H)-ones as a new class of H1-antihistaminic agents

A series of novel 2-phenyl-3-[2-(substituted amino) ethylamino] quinazolin-4(3H)-ones was synthesized by the nucleophilic substitution of 3-(2-bromo ethylamino)-2-phenyl quinazolin-4(3H)-one with various amines. The starting material, 3-(2-bromo ethylamino)-2-phenyl quinazolin-4(3H)-one, was synthesized from anthranilic acid by a multistep synthesis. All the title compounds were tested for their in vivo H₁-antihistaminic activity on conscious guinea pigs at the dose level of 10 mg/kg using chlorpheniramine as the standard drug. The results of the biologic activity revealed that all the test compounds protected the animals from histamine-induced bronchospasm significantly. Compound 2-phenyl-3-[2-(piperazinyl) ethylamino] quinazolin-4(3H)-one (S3) emerged as the most active compound of the series (73.67 % protection) when compared to the standard chlorpheniramine (70.09 % protection). Interestingly, compound S3 shows negligible sedation (8.21 %) compared to chlorpheniramine maleate (29.58 %). Therefore, compound S3 can serve as the lead molecule for further development into a new class of H₁-antihistaminic agents.     

Synthesis of 2-[4,5-dimethyl-1-(phenylamino)-1H-imidazol-2-ylthio]-N-(thiazole-2-yl)acetamide derivatives and their anticancer activities

In this work, 2-(4,5-dimethyl-1-(phenylamino)-1H-imidazol-2-ylthio)-N-(thiazol-2-yl) acetamide derivatives were synthesized by reacting 4,5-dimethyl-1-(phenylamino)-1H-imidazole-2(3H)-thione derivatives with some 2-chloro-N-(thiazol-2-yl)acetamide compounds. The structure of synthesized compounds was confirmed by IR, ¹H NMR, and mass spectra. Anticancer activities of the compounds selected by the National Cancer Institute were investigated by testing against a panel of 60 different human tumor cell lines derived from nine neoplastic cancer types. Compounds 7, 13, and 23 exhibited reasonable anticancer activity against the screened cancer types with relatively low GI₅₀ values. The compounds showed high activity against melanoma-type cell lines.     

Design and synthesis of 3-(4-chlorophenyl)-2-(2-(4-substituted)-2-oxoethylthio)quinazolin-4(3H)-one as antihistamine agents

A series of novel 3-(4-chlorophenyl)-2-(2-(4-substituted)-2-oxoethylthio)quinazolin-4(3H)-one was synthesized by the reaction of 2-(3-(4-chlorophenyl)-4-oxo-3,4-dihydroquinazolin-2-ylthio)acetyl chloride with various amines. The starting material, (3-(4-chlorophenyl)-4-oxo-3,4-dihydroquinazolin-2-ylthio)acetyl chloride was synthesized from 4-chloroaniline by a multistep synthesis. All the title compounds were tested for their in vivo H₁-antihistaminic activity on conscious guinea pigs at the dose level of 10 mg/kg using chlorpheniramine maleate as the reference standard. The results of the biological activity indicate that the test compounds protected the animals from histamine-induced bronchospasm significantly. Compound 3-(4-chlorophenyl)-2-(2-(4-methylpiperazin-1-yl)-2-oxoethylthio)quinazolin-4(3H)-one (1) emerged as the most potent compound of the series (71.13 % protection) when compared to the reference standard chlorpheniramine maleate (70.09 % protection). Interestingly, compound A1 shows negligible sedation (12 %) compared to chlorpheniramine maleate (32 %). Therefore, compound A1 can serve as the lead molecule for further development.     

Synthesis and preliminary evaluation activity studies of novel 4-(aryl/heteroaryl-2-ylmethyl)-6-phenyl-2-[3-(4-substituted-piperazine-1-yl)propyl]pyridazin-3(2H)-one derivatives as anticancer agents

A series of new 4-(aryl/heteroaryl-2-ylmethyl)-6-phenyl-2-[3-(4-substituted piperazine-1-yl)propyl] pyridazin-3(2H)-one derivatives were synthesized. The structures of the compounds were confirmed by IR, ¹H NMR, and mass spectral data. All the compounds were evaluated for their cytotoxicity toward five human cancer cell lines of different origins viz; HeLa (Cervical), SKBR3 (Breast), HCT116 (Colon), A375 (Skin) & H1299 (Lung) at different concentrations and the IC₅₀ values were determined. HCT116 and HeLa are the most sensitive against the compounds studied. One of them displayed moderate cytotoxicity against SKBR3. Majority of the compounds exhibited good to moderate activity.     

Synthesis and evaluation of antibacterial and antifungal activities of new (Z)-3-bromo-4-(1,3-diaryl-1H-pyrazol-4-yl)but-3-en-2-ones and 4-(3-methyl-1-phenyl-1H-pyrazol-5-yl)-1,3-diaryl-1H-pyrazoles

Bromination of 4-(1, 3-diaryl-1H-pyrazol-4-yl) but-3-en-2-ones, triggered by a combination of potassium bromide and cerium(IV) ammonium nitrate in a biphasic system consisting of water and dichloromethane furnishes the corresponding monobromo compounds 2 directly, instead of the expected dibromo compounds. The α-bromo compounds 2 were utilized as efficient precursors for the synthesis of several bipyrazolyl derivatives, 4-(3-methyl-1-phenyl-1H-pyrazol-5-yl)-1, 3-diaryl-1H-pyrazoles (3). All the α-bromoenones 2 and bipyrazoles 3 are new compounds and their identity was established by m.p., spectral and analytical data. The new products 2 and 3 were tested for their in vitro antibacterial activity against Staphylococcus aureus, Bacillus subtilis (Gram positive), Escherichia coli, and Pseudomonas aeruginosa (Gram negative) and antifungal activity against Aspergilus flavus and Aspergillus niger. The antimicrobial activity of the tested compounds is compared with the commercially available antibiotic, ciprofloxacin and antifungal agent, fluconazole.     

新型苯并咪唑类人顶体酶抑制剂的设计、合成及活性研究

目的基于人精子顶体酶活性位点的三维结构设计并合成新型苯并咪唑类衍生物。方法计算机模拟设计及化学合成。结果设计并合成了10个苯并咪唑类化合物,进行了抑酶活性测试。结论所有合成的化合物具有较好的抑酶活性,其中化合物8a是对照物Nα-对甲苯磺酰-L-赖氨酸氯甲基酮(TLCK)的1426倍。     

Synthesis of new 3-aryl-4-(3-aryl-4,5-dihydro-1H-pyrazol-5-yl)-1-phenyl-1H-pyrazole derivatives as potential antimicrobial agents

New (E)-1-aryl-3-(3-aryl-1-phenyl-1H-pyrazol-4-yl)prop-2-en-1-ones 6 (pyrazolic chalcones) were synthesized from Claisen–Schmidt reaction of 3-aryl-1-phenylpyrazol-4-carboxaldehydes 4 with several acetophenone derivatives 5. Subsequently, the cyclocondensation reaction of chalcones 6 with phenylhydrazine in acetic acid medium afforded the new 3-aryl-4-(3-aryl-4,5-dihydro-1H-pyrazol-5-yl)-1-phenyl-1H-pyrazoles 7. The synthesized compounds were characterized by spectral studies and evaluated for their in vitro antibacterial activity against three pathogenic bacterial strains, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, and in vitro antifungal activity against three pathogenic fungal strains Aspergillus flavus, Chrysosporium keratinophilum, and Candida albicans.     

Synthesis, evaluation of antimicrobial activity, and molecular modeling of novel 2-((4-(2H-benzo[d] [1,2,3] triazol-2-yl)piperidin-1-yl)methyl)-5-substituted phenyl-1,3,4-oxadiazoles

A new series of 2-((4-(2H-benzo[d][1,2,3]triazol-2-yl)piperidin-1-yl)methyl)-5-substituted-1-yl)-acetic acid hydrazide (3) with various substituted aromatic carboxylic acids phenyl-1,3,4-oxadiazoles (4a–j) were synthesized by cyclization of 4-benzotriazol-2-yl-piperidin in the presence of POCl₃. The structures were characterized by spectral data. The representative examples were screened invitro antibacterial activity and antifungal activity. The compounds showed significant antibacterial activity and showed moderate antifungal activity as that of standards, respectively. The data were further compared with structure-based investigations using docking studies with the crystal structure of oxidoreductase (1XDQ) protein organism: Escherichia coli for antibacterial activity and oxidoreductase (3QLS) protein, organism: Candida albicans for antifungal activity. The score values estimated by genetic algorithm were found to have a good correlation with the experimental inhibitory potencies.     

7-chloro-3-(substituted benzylidene/phenyl ethylidene amino)-2-phenylquinazolin-4(3H)-ones: synthesis, antimicrobial and antitubercular evaluation

In this study, a series of 7-chloro-3-(substituted benzylidene/phenyl ethylidene amino)-2-phenyl quinazolin-4(3H)-ones (1–10) were prepared and evaluated for antitubercular activity against Mycobacterium tuberculosis (MTB). The antitubercular screening results indicated that 7-chloro-3-(4-(dimethylamino)benzylidene amino)-2-phenylquinazolin-4(3H)-one (10) was the most potent one (MIC?=?0.78?×?10^?3?μM) and exhibited activity equivalent to the standard compound isoniazid (MIC?=?0.80?×?10^?3?μM). Further, the synthesized compounds were tested for their antibacterial activity against Gram positive and Gram negative bacteria. The comparison of antibacterial and antimycobacterial results indicated that different structural requirements are necessary for a compound to be effective against bacterial and mycobacterial targets.     

Synthesis and QSAR modeling 1-[3-methyl-2-(aryldiazenyl)-2H-aziren-2-yl]ethanones as potential antibacterial agents

The present communication deals with the synthesis of a series of 1-[3-methyl-2-(aryldiazenyl)-2H-aziren-2-yl]ethanones. The compounds were synthesized in excellent yields (70–80 %), and the structures were established on the basis of consistent IR, ¹H NMR, and elemental analysis data. The purity has been ascertained by chromatographic resolution using hexane–ethyl acetate (6:4 v/v) as binary eluent. All the compounds have been tested for their antimicrobial activity against a representative panel of bacteria i.e., Bacillus subtilis, Escherichia coli, Pseudomonas diminuta, and Staphylococcus aureus using Chloramphenicol as reference drug. All the synthesized compounds were found to exhibit profound antimicrobial activity.     

Synthesis and in vitro cytotoxicity study of 3-(1H-indol-3-yl)-1,3-diphenylpropan-1-ones

A series of 3-(1H-indol-3-yl)-1,3-diphenylpropan-1-ones 3a–l were synthesized in good to excellent yield by Michael addition of indole 1 with α,β-unsaturated ketones 2a–l in presence of indium(III) sulphate (20 mol%). The structure of the title compounds were established by ¹H NMR, ¹³C NMR, mass and elemental analysis. All the synthesized compounds were evaluated for in vitro cytotoxicity against five different cancer cell lines such as ACHN (human kidney adenocarcinoma), Panc1 (pancreatic), Calu1 (lung), H460 (non small cell lung), HCT116 (human colon cancer cell) and MCF10A (normal breast epithelium) using propidium iodide staining assay protocol. The result showed that the compounds 3e and 3l have excellent cytotoxic activity with the IC₅₀ value ranging from 1.4–2.7 to 2.4–3.4 μM, respectively, in comparison with the other compounds, Flavopiridol and Gemcitabine were employed as a positive control. The findings conferred 3-(1H-indol-3-yl)-1,3-diphenylpropan-1-ones seem to be promising candidates for the development of new anticancer drugs.     

Synthesis of 2-(aryl)-5-(arylidene)-4-thiazolidinone derivatives with potential analgesic and anti-inflammatory activity

A series of novel N-[5-(arylidene)-2-(aryl)-4-oxo-thiazolidin-3-yl]-4-biphenylcarboxamide derivatives was synthesized and evaluated for analgesic and anti-inflammatory activity. In this study, biphenyl-4-carboxylic acid hydrazide was converted to the corresponding aryl hydrazones using aryl aldehydes in the presence of catalytic amount of glacial acetic acid. The aryl hydrazones on reaction with thioglycolic acid in the presence of anhydrous zinc chloride yielded N-[2-(aryl)-4-oxo-thiazolidin-3-yl]-4-biphenylcarboxamide which further on reaction with aromatic aldehydes in the presence of anhydrous sodium acetate and glacial acetic acid furnished the title compounds. All compound exhibited anti-inflammatory activity at the dose 10?mg/kg. The structures of all these newly synthesized compounds were confirmed by their elemental analyses (C, H, N) and spectral data (IR and ¹H NMR).     

Synthesis and antimycobacterial activities of some new N-acylhydrazone and thiosemicarbazide derivatives of 6-methyl-4,5-dihydropyridazin-3(2H)-one

In this study, twenty-five new 6-methyl-4,5-dihydropyridazin-3(2H)-one derivatives having N-acylhydrazone and thiosemicarbazide moieties were synthesized. The target compounds were tested for their antimycobacterial activity in vitro against Mycobacterium tuberculosis H₃₇R_v using the agar dilution method. Among the synthesized compounds, N′-(2,4-dichlorobenzylidene)-2-(3-methyl-6-oxo-5,6-dihydropyridazin-1(4H)-yl)acetohydrazide 4g was found to be the most active compound with minimum inhibitory concentration of 0.78?μM and was more potent than ethambutol and ciprofloxacin.     

Synthesis and In Vitro Evaluation of 3-(1-Azolylmethyl)-1H-indoles and 3-(1-Azolyl-1-phenylmethyl)-1H-indoles as Inhibitors of P450 arom

In the challenge to develop potent inhibitors of aromatase for reducing the levels of estrogens, we found that azolyl-substituted indoles inhibit aromatase activity. 3-(1-Azolylmethyl)-1H-indoles 9–15 and 3-(1-azolyl-1-phenylmethyl)-1H-indoles 22–25 were prepared, and tested on their ability to inhibit P450 arom. Analysis of the inhibitory effect exerted by several derivatives ( 11, 12, 22 , and 23 ) on microsomal aromatase in vitro activity indicates that azolyl-substituted indoles containing an imidazole moiety are more potent inhibitors than triazole derivatives. In the first series, the introduction of the N-benzyl moiety has been found to enhance the inhibitory profile of these 3-(1-azolylmethyl)-1H-indole derivatives. The corresponding 4-fluoro derivative 12 displays the highest inhibitory activity (IC₅₀ = 0.0718 μM) of all investigated compounds; thus, 12 is 258 times as potent as aminoglutethimide (AG). The presence of a chloro grouping in para position of the phenyl ring in compounds 22 and 24 exerts a positive effect only in the triazol-1-yl sub-series: compound 25 is 4-fold more potent than 24 .     

Synthesis and cytotoxicity of novel 4-(4-(substituted)-1H-1,2,3-triazol-1-yl)-N-phenethylbenzenesulfonamides

A new series of 4-(4-(substituted)-1H-1,2,3-triazol-1-yl)-N-phenethylbenzenesulfonamide derivatives 5 were synthesized through the Click approach and evaluated for their cytotoxic activity against four cancer cell lines (HuCCA-1, HepG2, A549, and MOLT-3). Most of the synthesized triazoles 5 displayed cytotoxicity against MOLT-3 cell line, except for analogs 5a–c and 5e. Significantly, 4-phenyltriazoles (5a and 5n), 4-(naphthalen-2-yloxy)methyltriazole 5d, as well as 4-((2-oxo-2H-chromen-7-yl)oxy)methyltriazole 5l showed higher cytotoxic activity against HepG2 cells than the reference drug, etoposide. Interestingly, the 4-phenyltriazole 5a was the most potent and promising compound with IC₅₀ value of 9.07 μM against HepG2 cell line. The analog 5a also exerted the highest cytotoxic activity against HuCCA-1 cells. This finding provides the novel lead molecules for further development.     

Synthesis and biological studies of a novel series of 4-(4-(1H-imidazol-1-yl)phenyl)-6-arylpyrimidin-2-amines

A novel series of eleven 4-(4-(1H-imidazol-1-yl)phenyl)-6-arylpyrimidin-2-amines has been prepared from synthesized 3-[4-(1H-imidazol-1-yl) phenyl]prop-2-en-1-ones and evaluated for phosphodiesterase (PDE) inhibition and antimicrobial activities. N-arylation of imidazole with 4-fluorobenzaldehyde using hexadecyltrimethylammonium bromide as catalyst gave 4-(1H-imidazol-1-yl) benzaldehyde which on treatment with substituted acetophenones yielded corresponding chalcones (1a–1k). Each chalcone on further reaction with guanidine hydrochloride resulted in title compounds (2a–2k). Pyrimidines thus synthesized were subjected to biological studies. Some compounds showed marked activities in PDE inhibition and anti-bacterial and anti-fungal bioassays.