Synthesis and evaluation of anticonvulsant and antimicrobial activities of 3-hydroxy-6-methyl-2-substituted 4h-pyran-4-one derivatives

In this study, thirteen 3-hydroxy-6-methyl-2-substituted 4H-pyran-4-one derivatives were synthesized for the evaluation of their potential anticonvulsant activity. Mannich bases were prepared by the reaction of substituted piperazine derivatives with allomaltol and formaline. The structures of the synthesized compounds were confirmed by IR, (1)H-NMR and elemental analysis. Their anticonvulsant activities were determined in vivo by maximal electroshock (MES), sub-cutaneous Metrazol (scMet), and rotorod toxicity tests for neurological deficits. The antimicrobial activities of the synthesized compounds were investigated in vitro against some bacteria and fungi using the microdilution broth method. Ac-cording to the activity studies, 3-hydroxy-6-methyl-2-[4-(2-trifluoromethyl-phenyl)-piperazin-1-ylmethyl]-4H-pyran-4-one (3i) was the compound determined to be most active in the scMet test for all doses at four hours and for the 300 mg/kg dose at half an hour. 2-[4-(4-Chloro-phenyl)-piperazin-1-ylmethyl]-3-hydroxy-6-methyl-4H-pyran-4-one (3f) was found to be protective against MES whereas 2-chlorophenyl derivative (3e) was not. Looking at the antifungal activity results, compounds 3b, 3h, and 3i were determined to have activity against all fungi.     

Design, synthesis, and in vitro antitumor activity evaluation of novel 4-pyrrylamino quinazoline derivatives

Here, we describe the design and synthesis of two series of 4-pyrrylamino quinazolines as new analogs of the epidermal growth factor receptor inhibitor gefitinib. In vitro antitumor activity of these novel compounds against pancreatic (Miapaca2) and prostate (DU145) cancer cell lines was evaluated. Compared with the parental gefitinib, all 18 derivatives show a greatly increased cytotoxicity to cancer cells. In vitro kinase inhibitory activity on epidermal growth factor receptor was also investigated. Among them, compounds GI-6, GII-4, GII-6, GII-8, and GII-9 are more potential receptor tyrosine kinase (RTK) inhibitors. Based on these results, we propose simple structure-activity relationship to provide information for designing and developing more potent antitumor agents.     

Synthesis of some novel substituted purine derivatives as potential anticancer, anti-HIV-1 and antimicrobial agents

In search of novel purine antimetabolites, a series of 8-substituted methylxanthine derivatives was prepared in order to explore their in vitro anticancer, anti-HIV-1 and antimicrobial activities. The target compounds include: 8-[(3-substituted-4-oxo-thiazolidin-2-ylidene)hydrazino]-1,3-dimethyl (or 1,3,7-trimethyl)-3,7-dihydropurine-2,6-diones 5a-e, 8-[(3,4-disubstituted 2,3-dihydrothiazol-2-ylidene)hydrazino]-1,3,7-trimethyl-3,7-dihydropurine-2,6-diones 6a-d and 8-(5-amino-3-arylpyrazol-1-yl)-1,3-dimethyl- (or 1,3,7-trimethyl)-3,7-dihydropurine-2,6-diones 7a-g. The in vitro anticancer results revealed that compound 5d exhibited a super sensitivity profile towards leukemia K-562 with a GI(50) value of <0.01 microM. Compound 7c showed significant activity against colon cancer HCT-15 and renal cancer CAKI-1 (GI(50) values of 0.47 and 0.78 microM, respectively). Compound 7a displayed high activity against colon cancer HCT-15 (GI(50 )= 0.8 microM). The anti-HIV-1 results indicated that compound 6b displayed a good reduction of viral cytopathic effect (56.69%). The antimicrobial results showed that compound 5a was four times more active than ampicillin against P. aerugenosa (MIC =or< 25 microg/mL), compound 5b had twice the activity of ampicillin, while compounds 5d, 7c and 7f were equipotent to ampicillin. On the other hand, compound 7a was equipotent to ampicillin against P. vulgaris (MIC = 50 microg/mL).     

Synthesis antimicrobial and antifungal activity of some new 3 substituted derivatives of 4-(2,4-dichlorophenyl)-5-adamantyl-1H-1,2,4-triazole

The synthesis of a series of substituted hydrazones and thiazolidinones is described, starting from N-[4-(2,4-dichlorophenyl)-5-adamantyl-1H-1,2,4-triazol-3-ylmercaptoacetyl]hydrazine. The new compounds were tested for antimicrobial and antifungal activity and some of them exhibited moderate activity against Candida albicans.     

Synthesis,molecular docking studies,and biological evaluation of novel alkyl bis(4‐amino‐5‐cyanopyrimidine) derivatives

A series of bis(4‐amino‐5‐cyano‐pyrimidines) was synthesized and evaluated as dual inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). To further explore the multifunctional properties of the new derivatives, their antioxidant and antibacterial activities were also tested. The results showed that most of these compounds could effectively inhibit AChE and BChE. Particularly, compound 7c exhibited the best AChE inhibitory activity (IC₅₀ = 5.72 ± 1.53 μM), whereas compound 7h was identified as the most potent BChE inhibitor (IC₅₀ = 12.19 ± 0.57 μM). Molecular modeling study revealed that compounds 7c, 7f , and 7b showed a higher inhibitory activity than that of galantamine against both AChE and BChE. Anticholinesterase activity of compounds 7h, 7b , and 7c was significant in vitro and in silico for both enzymes, since these compounds have hydrophobic rings (Br‐phenyl, dimethyl, and methoxyphenyl), which bind very well in both sites. In addition to cholinesterase inhibitory activities, these compounds showed different levels of antioxidant activities. Indeed, in the superoxide–dimethyl sulfoxide alkaline assay, compound 7j showed very high inhibition (IC₅₀ = 0.37 ± 0.28 μM). Also, compound 7l exhibited strong and good antibacterial activity against Staphylococcus epidermidis and Staphylococcus aureus, respectively. Taking into account the results of biological evaluation, further modifications will be designed to increase potency on different targets. In this study, the obtained results can be a new starting point for further development of multifunctional agents for the treatment of Alzheimer's disease.     

Design,synthesis, and biological evaluation of novel 4‐phenoxypyridine derivatives as potential antitumor agents

A series of novel 4‐phenoxypyridine derivatives containing the 4‐oxo‐1,4‐dihydropyridazine‐3‐carboxamide moiety were synthesized and evaluated for their in vitro cytotoxic activity against the A549 cancer cell line, and some compounds were further examined for their cytotoxic activity against the H460, BGC823, MKN45, and HT‐29 cancer cell lines. Most of the compounds exhibited moderate to significant cytotoxicity. The most promising compound 15b (with VEGFR2 inhibitory concentration [IC₅₀] value of 0.23 μM) showed remarkable cytotoxicity against A549, BGC‐823, MKN45, H460, and HT‐29 cells, with IC₅₀ values of 0.75, 1.68, 2.63, 5.08 and 7.22 μM, respectively. Their preliminary structure‐activity relationship studies indicate that electron‐withdrawing groups on the terminal phenyl rings are beneficial for improving the antitumor activity. Moreover, treatment of A549 cells with compound 15b resulted in cell cycle arrest in the G₀/G₁ phase in a dose‐dependent manner. Further apoptotic studies and acridine orange/ethidium bromide staining were also performed on A549 cells, which showed that compound 15b could induce apoptosis. Wound‐healing assay results indicated that compound 15b strongly inhibited A549 cell motility.     

Synthesis,molecular docking and antimicrobial evaluation of novel benzoxazole derivatives

In this research, previously and newly synthesized 5-amino-2-(4-substitutedphenyl/benzyl)benzoxazoles (3a–3l) and 2-substituted-5-(4-nitro/aminophenylsulfonamido)benzoxazoles (5a–5l, 6a–6l) were evaluated for their antimicrobial activities against Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 29212 and Mycobacterium tuberculosis H37RV ATCC 27294 and their drug-resistant isolates Candida albicans ATCC 10231 and Candida krusei ATCC 6258. The chemical structures of the newly synthesized compounds were characterized by IR, ¹H NMR, ¹³C NMR, LC–MS and elemental analysis. Microbiological results indicated that the compounds possessed a broad spectrum of activity against the tested microorganisms at the minimum inhibitory concentration (MIC) values between 256 and 8 µg/mL. Compounds 3a, 3c and 3f exhibited significant antimycobacterial activity showing MIC value of 8 µg/mL against both M. tuberculosis and its drug-resistant isolate. InhA, the enoyl-acyl carrier protein reductase from M. tuberculosis, is one of the key enzymes in the FASII system involved in mycobacterial fatty acid elongation cycle, which has been validated as an effective antimicrobial target. Molecular docking into active site of InhA was performed on 3FNE.PDB file to understand ligand–protein interactions. The compounds obtained from this research can be used as scaffolds in the design of new potent drugs.     

含异羟肟酸喹唑啉类非可逆EGFR/HDAC双靶点抑制剂的合成及抗肿瘤活性研究

目的 设计、合成含异羟肟酸片段的4-芳氨基喹唑啉类衍生物,评价其体外抗肿瘤活性.方法 以4-芳氨基-6-硝基-7-羟基喹唑啉为起始原料,经取代、还原、酰化、还原、缩合及脱保护6步反应得到目标化合物,采用MTT法测定目标化合物对人表皮癌细胞系A431、人肺腺癌细胞系H1975、人宫颈癌细胞系HeLa和人肝癌细胞系HepG...     

Synthesis and biological evaluation of 6-bromo-6-substituted penicillanic acid derivatives as beta-lactamase inhibitors

The synthesis of a selected set of 6-bromopenicillanic acid derivatives with an additional C6 substituent is reported. All these substances were tested as inhibitors of class A and C beta-lactamase enzymes derived from Escherichia coli (TEM-1) and E. cloacae (P99). As 6-(1-hydroxyethyl) derivatives 4c and 6c were found to be weak beta-lactamase inhibitors, they were further investigated in combination with amoxicillin against a series of beta-lactamase-producing bacterial strains. Some structure-activity relationships are discussed.     

Synthesis and antimicrobial activity of some new N-substituted quinoline derivatives of 1H-pyrazole

A new series of 32 derivatives of 4-pyrazolyl-N-(hetero)arylquinoline 5a-p and 6a-p were synthesized by a one-pot base-catalyzed cyclocondensation reaction of 1-phenyl-3-(hetero)aryl-pyrazole-4-carbaldehyde 1a-h, malononitrile 2, and 3-(hetero)aryl-5,5-disubstitutedcyclohex-2-enone 3a-b or 4a-b, respectively. All the synthesized compounds were characterized by elemental analysis, FT-IR, (1) H-NMR, and (13) C-NMR spectral data. All the synthesized compounds were screened, against six bacterial pathogens, namely Bacillus subtilis, Clostridium tetani, Streptococcus pneumoniae, Salmonella typhi, Vibrio cholerae, Escherichia coli, and antifungal activity, against two fungal pathogens Aspergillus fumigatus and Candida albicans, using broth microdilution MIC method. Some of the compounds were found to be more or equipotent against most of the employed strains than commercially available drugs as evident from the screening data.     

新型4-苯胺基喹唑啉类酪氨酸激酶抑制剂的抗肿瘤活性研究

目的 对合成的新型4-苯胺基喹唑啉类酪氨酸激酶抑制剂TYIG1～TYIG9进行抗肿瘤活性研究,为寻找具有靶向抗肿瘤活性的候选化合物提供依据。方法 采用均相时间分辨荧光（HTRF）法对化合物进行EGFR、VEGFR-2两个靶点的体外活性筛选;采用MTS法对化合物进行肿瘤细胞（A431、A549、H1975、MDA-MB-231）增殖抑制的体外活性评价;采用人肺癌H1975细胞的移植瘤裸鼠模型评价其在动物体内抗肿瘤活性。结果 采用HTRF法从合成的一系列化合物中筛选出化合物TYIG4~TYIG9对EGFR、VEGFR-2激酶的活性较好。MTS法检测得到这6个化合物对4种肿瘤细胞（A431、A549、H1975、MDA-MB-231）均有不同程度的抑制作用,其中TYIG6的增殖抑制作用的选择性更为突出;体内试验结果表明TYIG6能够剂量相关性地抑制肿瘤生长,50、100 mg/kg TYIG6对H1975的相对肿瘤抑制率分别为42.59%、34.92%。结论 TYIG6具有良好的体内外抗肿瘤活性,具有成为新型双靶点酪氨酸激酶抑制剂的潜能,有进一步的研究价值。     

Synthesis,biological evaluation,and docking studies of some 5‐chloro‐2(3H)‐benzoxazolone Mannich bases derivatives as cholinesterase inhibitors

A series of N‐substituted‐5‐chloro‐2(3H)‐benzoxazolone derivatives were synthesized and evaluated for their acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) inhibitory, and antioxidant activities. The structures of the title compounds were confirmed by spectral and elemental analyses. The cholinesterase (ChE) inhibitory activity studies were carried out using Ellman's colorimetric method. The free radical scavenging activity was also determined by in vitro ABTS (2,2‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid)) assay. The biological activity results revealed that all of the title compounds displayed higher AChE inhibitory activity than the reference compound, rivastigmine, and were selective for AChE. Among the tested compounds, compound 7 exhibited the highest inhibition against AChE (IC₅₀ = 7.53 ± 0.17 μM), while compound 11 was found to be the most active compound against BuChE (IC₅₀ = 17.50 ± 0.29 μM). The molecular docking study of compound 7 showed that this compound can interact with the catalytic active site (CAS) of AChE and also has potential metal chelating ability and a proper log P value. On the other hand, compound 2 bearing a methyl substituent at the ortho position on the phenyl ring showed better radical scavenging activity (IC₅₀ = 1.04 ± 0.04 mM) than Trolox (IC₅₀ = 1.50 ± 0.05 mM).

     

Synthesis and evaluation of some novel quinazolinone derivatives as diuretic agents

A new series of quinazolin-4(3H)-one derivatives containing either a thiazole or a 1, 3, 4-thiadiazole moiety were prepared in order to study the effect of such a heterocyclic combination on the expected diuretic activity. Synthesis of the target compounds (2, 4, and 6) has been achieved through an interaction of the starting 7-chloro-2-methyl-4H-3, 1-benzoxazin-4-one 1 with different heterocyclic amines. Alkylation of 3-(2-mercapto-1, 3, 4-thiadiazol-5-yl)quinazolin-4(3H)-one derivative 4 with different alkyl halides or chloroacetic acid afforded the corresponding thioethers 5 while interaction of 2-methyl-3-(1, 3, 4-thiadiazol-5-yl or thiazol-5-yl)quinazolin-4(3H)-ones (2 and 6) with various aromatic aldehydes resulted in the formation of the arylvinyl analogs 3 and 7, respectively. On the other hand, 2-morpholinomethyl-3-(2-sulfamoyl or mercapto-1, 3, 4-thiadiazol-5-yl)quinazolin-4(3H)-one derivatives 10 have also been synthesized through an interaction of the sulfonamide or thiol analog 9 with the appropriate amine. Biological evaluation of some of the target compounds as diuretic agents was carried out. The results showed that 2-[2-(4-chlorophenyl)vinyl]-7-chloro-3-(2-sulfamoyl-1, 3, 4-thiadiazol-5-yl)quinazolin-4(3H)-one 7b exhibited significant diuretic activity. The detailed synthesis, spectroscopic and biological data are reported.     

Synthesis, molecular docking, and biological evaluation of novel triazole derivatives as antifungal agents

Twenty-eight novel triazole derivatives (compounds 1a-v, 2a-f) have been synthesized for structure–activity relationship studies as antifungal agents. The compounds were designed on the basis of the structure of fluconazole and molecular modeling of the active site of the cytochrome P450 14α-demethylase (CYP51). All of them are reported for the first time. Their chemical structures are characterized by ¹H NMR, ¹³C NMR, LC-MS, and elemental analysis. The antifungal activities have been evaluated in vitro by measuring the minimal inhibitory concentrations (MICs). Compounds 1a-v exhibited higher activity against nearly all fungi tested except Aspergillus fumigatus (A. fum) than fluconazole (FCZ). The computational molecular docking experiments indicated that the inhibition of CYP51 involves a coordination bond with iron of the heme group, a hydrophilic H-bonding region, a hydrophobic region, and a narrow hydrophobic binding cleft.     

Synthesis and antimicrobial evaluation of novel platensimycin analogues

Since the isolation of the natural products platensimycin and platencin as new antibiotic lead structures, several total syntheses as well as syntheses of derivatives have been developed. Most of these approaches are very laborious and the target molecules are often produced in only poor overall yields. The following approach describes the synthesis of rather simple platensimycin analogues focussing on some structure elements that have previously been identified as being essential for binding to the Fab F enzyme in fatty acid biosynthesis. Two of the new analogues show significant antimicrobial activities.     

Synthesis and in-vitro antibacterial activity of 5-substituted 1-methyl-4-nitro-1H-imidazoles

A series of 5-substituted 1-methyl-4-nitro-1H-imidazole derivatives were synthesized and evaluated for in-vitro antibacterial activity against a panel of microorganisms including Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli, Klebsiella pneumonia, Enterobacter aerogenes, and Helicobacter pylori using conventional agar dilution method. Among the test compounds, 1-methyl-4-nitro-5-(phenylsulfonyl)-1H-imidazole was the most potent against Gram-positive bacteria, with a MIC value of < or =8 microg/mL. All compounds showed no significant activity against Gram-negative bacteria at concentrations < or =64 microg/mL. The MIC values against 15 clinical isolates of H. pylori indicated that compounds 10 and 11 were the most active compounds in this series in terms of inhibiting the growth of H. pylori (MIC = 2 microg/mL). It was also demonstrated that their corresponding activities were four times larger than that of metronidazole.     

Synthesis and pharmacological evaluation of novel antinociceptive N-substituted-phenylimidazolyl-4-acylhydrazone derivatives

This paper describes recent results of design, synthesis and pharmacological evaluation of new N-heterocyclic functionalized N-acylhydrazone compounds (NAH), belonging to the N-substituted-phenylimidazolyl-4-acylhydrazone class (3a-o). These compounds were planned by applying the molecular hybridization strategy to propose the structural modifications on the previously described functionalized 2-methyl-imidazolyl-3-acylhydrazone class (2), which presented an important analgesic profile. This new series (3) was synthesized in order to investigate the possible pharmacophoric contribution of the N-heteroaromatic ring and N-acylhydrazone moieties to the analgesic activity. Compounds 3g and 3n are the most potent analgesic agents from this series, at the screening dose of 100 mg/kg p.o. and compounds 3e, 3j and 3o presented the best antiinflammatory properties at the same screening concentration.     

Synthesis,characterization, and antimicrobial evaluation of carbostyril derivatives of 1H-pyrazole

A new series of 12 derivatives of 4-pyrazolyl-N-arylquinoline-2,5-dione (4a–l) were synthesized by one pot base catalyzed cyclocondensation reaction of 1-aryl-5-chloro-3-methyl-1H-pyrazole-4-carbaldehyde (1a–c), Meldrum’s acid (2) and 3-arylamino-5,5-disubstitutedcyclohex-2-enone (3a–d). All the compounds were characterized by elemental analysis, FT-IR, ¹H NMR and ¹³C NMR spectral data and were screened, against six bacterial pathogens, namely Bacillus subtilis, Clostridium tetani, Streptococcus pneumoniae, Salmonella typhi, Vibrio cholerae, Escherichia coli and antifungal activity, against two fungal pathogens Aspergillus fumigatus and Candida albicans, using broth microdilution MIC (minimum inhibitory concentration) method. Some of the compounds were found to be equipotent or more potent than commercial drugs, against most of the employed strains, as evident from the screening data.     

Synthesis and antimicrobial activity of some pyridinyliminothiazoline derivatives

The synthesis of some pyridinyliminothiazoline derivatives starting from N-pyridine-N'-phenyl thiourea and alpha-halogenoacetophenones is described. The chemical structures of the compounds were elucidated. The prepared compounds were tested for antimicrobial activity.