Biological activity of synthesized 5-{1-[(4-chlorophenyl)sulfonyl]piperidin-4-yl}-2-mercapto-1, 3, 4-oxadiazole derivatives demonstrated by in silico and BSA binding studies

We synthesized a series of compounds bearing pharmacologically important 1,3,4-oxadiazole and piperidine moieties. Spectral data analysis by 1H-NMR, 13C-NMR, IR and EI-MS was used to elucidate the structures of the synthesized molecules. Docking studies explained the different types of interaction of the compounds with amino acids, while bovine serum albumin (BSA) binding interactions showed their pharmacological effectiveness. Antibacterial screening of these compounds demonstrated moderate to strong activity against Salmonella typhi and Bacillus subtilis but only weak to moderate activity against the other three bacterial strains tested. Seven compounds were the most active members as acetyl cholinesterase inhibitors. All the compounds presented displayed strong inhibitory activity against urease. Compounds 7l, 7m, 7n, 7o, 7p, 7r, 7u, 7v, 7x and 7v were highly active, with respective IC50 values of 2.14±0.003, 0.63±0.001, 2.17±0.006, 1.13±0.003, 1.21±0.005, 6.28±0.003, 2.39±0.005, 2.15±0.002, 2.26±0.003 and 2.14±0.002 µM, compared to thiourea, used as the reference standard (IC50 = 21.25±0.15 µM). These new urease inhibitors could replace existing drugs after their evaluation in comprehensive in vivo studies.

Synthesis of new 2-{2,3-dihydro-1, 4-benzodioxin-6-yl[(4-methylphenyl) sulfonyl]amino}-N-(un/substituted-phenyl)acetamides as α-glucosidase and acetylcholinesterase inhibitors and their in silico study

The aim of the present research work was to investigate the enzyme inhibitory potential of some new sulfonamides having benzodioxane and acetamide moieties. The synthesis was started by the reaction of N-2,3-dihydrobenzo[1,4]-dioxin-6-amine (1) with 4-methylbenzenesulfonyl chloride (2) in the presence of 10% aqueous Na2CO3 to yield N-(2,3-dihydrobenzo[1,4]-dioxin-6-yl)-4-methylbenzenesulfonamide (3), which was then reacted with 2-bromo-N-(un/substituted-phenyl)acetamides (6a-l) in DMF and lithium hydride as a base to afford various 2-{2,3-dihydro-1,4-benzodioxin-6-yl[(4-methylphenyl)sulfonyl]amino}-N-(un/substituted-phenyl)acetamides (7a-l). All the synthesized compounds were characterized by their IR and 1H-NMR spectral data along with CHN analysis data. The enzyme inhibitory activities of these compounds were tested against a-glucosidase and acetylcholinesterase (AChE). Most of the compounds exhibited substantial inhibitory activity against yeast a-glucosidase and weak against AChE. The in silico molecular docking results were also consistent with in vitro enzyme inhibition data.

Synthesis and in silico study of 2-furyl(4-{4-[(substituted)sulfonyl]benzyl}-1-piperazinyl)methanone derivatives as suitable therapeutic agents

Abstract In the study presented here, a new series of 2-furyl(4-{4-[(substituted)sulfonyl]benzyl}-1-piperazinyl)methanone derivatives was targeted. The synthesis was initiated by the treatment of different secondary amines (1a-h) with 4-bromomethylbenzenesulfonyl chloride (2) to obtain various 1-{[4-(bromomethyl)phenyl]sulfonyl}amines (3a-h). 2-Furyl(1-piperazinyl)methanone (2-furoyl-1-piperazine; 4) was then dissolved in acetonitrile, with the addition of K2CO3, and the mixture was refluxed for activation. This activated molecule was further treated with equi-molar amounts of 3a-h to form targeted 2-furyl(4-{4-[(substituted)sulfonyl]benzyl}-1-piperazinyl)methanone derivatives (5a-h) in the same reaction set up. The structure confirmation of all the synthesized compounds was carried out by EI-MS, IR and 1H-NMR spectral analysis. The compounds showed good enzyme inhibitory activity. Compound 5h showed excellent inhibitory effect against acetyl- and butyrylcholinesterase with respective IC50 values of 2.91±0.001 and 4.35±0.004 µM, compared to eserine, a reference standard with IC50 values of 0.04±0.0001 and 0.85±0.001 µM, respectively, against these enzymes. All synthesized molecules were active against almost all Gram-positive and Gram-negative bacterial strains tested. The cytotoxicity of the molecules was also checked to determine their utility as possible therapeutic agents.

Synthesis, spectral analysis and pharmacological study of N'- substituted-2-(5-((2,4-dimethylphenoxy)methyl)-1,3,4-oxadiazol-2-ylthio)acetohydrazides

ABSTRACT A series of molecules bearing multiple functional groups were synthesized to study their antibiotic effect against Gram-positive and Gram-negative bacteria and lipoxygenase activity as well. 2,4-Dimethylcarbolic acid (1) was refluxed with ethyl 2-bromoacetate to synthesize ethyl 2-(2,4-dimethylphenoxy)acetate (2). Compound 2 was converted to the corresponding hydrazide 3, again on refluxing with hydrazine. The compound 5-((2,4-dimethylphenoxy)methyl)-1,3,4-oxadiazol-2-thiol (4) was synthesized by the reaction of 3 and CS2 in the presence of KOH. Compound 4 was further converted to the corresponding ester 5 and then 2-(5-((2,4-dimethylphenoxy)methyl)-1,3,4-oxadiazol-2-ylthio)acetohydrazide (6). The final molecules N'-substituted-2-(5-((2,4-dimethylphenoxy)methyl)-1,3,4-oxadiazol-2-ylthio)acetohydrazide, 8a-m, bearing ether, 1,3,4-oxadiazole, thioether, hydrazone and azomethine functional groups were synthesized by stirring the aryl carboxaldehydes 7a-m with 6 in methanol at room temperature. The depicted structures of all synthesized molecules were corroborated by IR, 1H-NMR and EIMS spectral data analysis. 8m and 8i showed substantial antibacterial activity and lipoxygenase inhibitory activity, respectively.

Synthesis of some novel enzyme inhibitors and antibacterial agents derived from 5-(1-(4-tosyl)piperidin-4-yl)-1, 3, 4-oxadiazol-2-thiol

ABSTRACT Keeping in mind the pharmacological importance of the 1,3,4-oxadiazole moiety, a series of new S-substituted derivatives, 5a-h, of 5-(1-(4-tosyl)piperidin-4-yl)-1,3,4-oxadiazol-2-thiol (3) were synthesized. The reaction of p-toluenesulfonyl chloride (a) and ethyl isonipecotate (b) produced ethyl 1-(4-tosyl)piperidin-4-carboxylate (1) which was further transformed into 1-(4-tosyl)piperidin-4-carbohydrazide (2) by hydrazine hydrate in methanol. Compound 2 was refluxed with CS2 in the presence of KOH to synthesize 5-(1-(4-tosyl)piperidin-4-yl)-1,3,4-oxadiazol-2-thiol (3). The desired compounds, 5a-h, were synthesized by stirring 3 with aralkyl halides, 4a-h, in DMF using NaH as an activator. The structures of synthesized compounds were elucidated by 1H-NMR, IR and EI-MS spectral studies. These compounds were further evaluated for enzyme inhibitory activity against lipoxygenase and alpha-glucosidase, along with antibacterial activity against Gram-negative and Gram-positive bacteria.

RESUMO Tendo em vista a importância farmacológica da porção 1,3,4-oxadiazol, sintetizou-se uma série de novos derivados S-substituídos, 5a-h, de 5-(1-(4-tosi)piperidin-4-il)-1,3,4-oxadiazol-2-tiol (3). A reação do cloreto de p-toluenossulfonila (a), com isonipecotato de (b) etila forneceu 1-(4-tosil)piperidin-4-carboxilato de metila (1), que foi, em seguida, transformado em 1-(4-tosil)piperidin-4-carbo-hidrazida (2) por reação com hidrato de hidrazina em metanol. O composto 2 foi submetido a refluxo com CS2 na presença de KOH para se obter 5-(1-(4-tosil)piperidin-4-il)-1,3,4-oxadiazol-2-tiol (3). Os compostos desejados, 5a-h, foram obtidos por agitação de 3 com haletos de aralquila, 4a-h, em DMF, na presença de NaH. As estruturas dos compostos sintetizados foram elucidadas através de análise dos espectros de 1H-MNR, IR e EI-MS. Estes compostos foram, ainda, avaliados quanto à inibição das enzimas lipoxigenase e alfa-glucosidase, juntamente com a atividade antibacteriana contra bactérias Gram positivas e Gram negativas.

Convergent synthesis of new N -substituted 2-{[5-(1H -indol-3-ylmethyl)-1, 3, 4-oxadiazol-2-yl]sulfanyl}acetamides as suitable therapeutic agents

abstract A series of N-substituted 2-{[5-(1H-indol-3-ylmethyl)-1,3,4-oxadiazol-2-yl]sulfanyl}acetamides (8a-w) was synthesized in three steps. The first step involved the sequential conversion of 2-(1H-indol-3-yl)acetic acid (1) to ester (2) followed by hydrazide (3) formation and finally cyclization in the presence of CS2 and alcoholic KOH yielded 5-(1H-indole-3-yl-methyl)-1,3,4-oxadiazole-2-thiol (4). In the second step, aryl/aralkyl amines (5a-w) were reacted with 2-bromoacetyl bromide (6) in basic medium to yield 2-bromo-N-substituted acetamides (7a-w). In the third step, these electrophiles (7a-w) were reacted with 4 to afford the target compounds (8a-w). Structural elucidation of all the synthesized derivatives was done by 1H-NMR, IR and EI-MS spectral techniques. Moreover, they were screened for antibacterial and hemolytic activity. Enzyme inhibition activity was well supported by molecular docking results, for example, compound 8q exhibited better inhibitory potential against α-glucosidase, while 8g and 8b exhibited comparatively better inhibition against butyrylcholinesterase and lipoxygenase, respectively. Similarly, compounds 8b and 8c showed very good antibacterial activity against Salmonella typhi, which was very close to that of ciprofloxacin, a standard antibiotic used in this study. 8c and 8l also showed very good antibacterial activity against Staphylococcus aureus as well. Almost all compounds showed very slight hemolytic activity, where 8p exhibited the least. Therefore, the molecules synthesized may have utility as suitable therapeutic agents.

resumo Uma série de acetamidas 2-{[5-(1H-indol-3-ilmetil)-1,3,4-oxadiazol-2-il]sulfanila} N-substituídas (8a-w) foi sintetizada em três fases. A primeira etapa envolveu a conversão sequencial de ácido 2-(1H-indol-3-il)acético (1) a éster (2), seguido por hidrazida (3) e, finalmente, a e ciclização na presença de CS2 e KOH alcoólico produziu 5-(1H-indol-3-il- metil)-1,3,4-oxadiazole-2-tiol (4). Na segunda etapa, aminas arílicas/aralquílicas(5a-w) reagiram com brometo de 2-bromoacetila (6​​), em meio básico, para se obter acetamidas 2-bromo-N-substituídas (7a-w). Na terceira etapa, estes eletrófilos (7a- w) reagiram com 4, para se obter os compostos alvo (8a-w). A elucidação estrutural de todos os derivados sintetizados foi realizada por 1H-NMR, IR e técnicas de espectrometria de EI-MS. Além disso, eles foram submetidos a triagem de atividade antibacteriana e hemolítica. Análise da inibição enzimática foi bem apoiada pelos resultados de docking molecular. Por exemplo, o composto 8q exibiu melhor potencial inibitório contra α-glicosidase, e os compostos 8g e 8b exibiram, comparativamente, melhor inibição contra butirilcolinesterase (BChE) elipoxigenase (LOX), respectivamente. Do mesmo modo os compostos 8b e 8c mostraram excelente potencial antibacteriano contra SalmonellaTyphi, semelhante ao do ciprofloxacino, antibiótico padrão usado neste estudo. Os compostos 8c e 8l também mostraram excelente potencial antibacteriano contra Staphylococcus aureus . Quase todos os compostos mostraram pequena atividade hemolítica, sendo que o composto 8p apresentou menor atividade. Assim, as moléculas sintetizadas podem ter a sua utilidade como agentes terapêuticos adequados.

Determination of Antioxidant Activity and Phytoconstituent Screening of Euphorbia heterophylla Linn.

Aim: To carry out qualitative determination of phytochemicals and evaluate antioxidant potential of Euphorbia heterophylla Linn. Place and Duration of Study: Department of Chemistry, Government College University Lahore, Pakistan, between October, 2011 and February, 2012. Material and Method: The methanolic extract of the plant was dissolved in distilled water and partitioned with n-hexane, chloroform, ethyl acetate and n-butanol sequentially. The antioxidant potential of all these fractions and remaining aqueous fraction was analyzed by these methods: 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging activity, total antioxidant activity, Ferric Reducing Antioxidant Power (FRAP) assay, Ferric Thiocyanate (FTC) assay while Folin-Ciocalteu colorimetric method was used to analyse total phenolic content. Phytochemical analysis were performed on the plant extracts to detect the presence of secondary metabolites. Results: Phytochemical screening revealed phenolics and flavonoids in abundance inchloroform soluble fraction, ethyl acetate soluble fraction and n-butanol soluble fraction. Also the ethyl acetate soluble fraction, n-butanol soluble fraction and remaining aqueous fraction contained saponins and sugars. Terpenoids were detected in all other fractions except the aqueous fraction. Alkaloids were determined in ethyl acetate and n-butanol soluble fraction only while tannins and cardiac glycosides were present in n-butanol soluble fraction and ethyl acetate soluble fraction respectively. Antioxidant assays revealed that Ethyl acetate soluble fraction exhibited highest percent inhibition of DPPH radical i.e. 80.09±0.87% at a concentration of 120 μg/ml as compared to other fractions. IC50 value of ethyl acetate fraction was found to be 36.85±1.8 μg/ml relative to ascorbic acid having IC50 value 58.8±0.89 μg/ml. It also showed the highest value of total antioxidant activity i.e. 0.918±0.08 as well as highest FRAP value 200.05±0.4 TE μM/ml, highest amount of total phenolic compounds (190.1±1.21 GAE mg/g) and highest percentage of inhibition of lipid peroxidation (54.23±0.57%). Chloroform soluble fraction showed IC50 value of 149.84±1.02, total antioxidant activity 0.739±0.06; FRAP value115.15±0.2 μM/ml, total phenolic content 137.1±1.4 GAE mg/g and 41.31±0.53% percent inhibition of lipid peroxidation. n-Butanol soluble fraction showed IC50 value of 117.67±0.7, total antioxidant activity 0.532±0.03, FRAP value127.5±0.9 μM/ml, total phenolic content 93.5±0.3 GAE mg/g and 32.15±0.9% percent inhibition of lipid peroxidation. n-Hexane soluble fraction showed IC50 value of 769.7±1.5, antioxidant activity 0.174±0.07, FRAP value 98.26±0.8 μM/ml, total phenolic content 19.5±1.23 GAE mg/g and 12.09±0.8% percent inhibition of lipid peroxidation. Aqueous fraction showed IC50 value of 669.3±1.04, antioxidant activity 0.152±0.041; FRAP value 68.7±0.3 μM/ml, total phenolic content 36.3±0.9 GAE mg/g and 25.01±0.96% percent inhibition of lipid peroxidation. Conclusion: Ethyl acetate soluble fraction was found to be rich in natural antioxidants and a good source of phytochemicals.

2-Phenitidine derivatives as suitable inhibitors of butyrylcholinesterase

This manuscript reports the synthesis of a series of N-substituted derivatives of 2-phenitidine. First, the reaction of 2-phenitidine (1) with benzene sulfonyl chloride (2) yielded N-(2-ethoxyphenyl) benzenesulfonamide (3), which further on treatment with sodium hydride and alkyl halides (4a-g) furnished into new sulfonamides (5a-g). Second, the phenitidine reacted with benzoyl chloride (6) and acetyl chloride (8) to yield the reported N-benzoyl phenitidine (7) and N-acetyl phenitidine (9), respectively. These derivatives were characterized by infrared spectroscopy, ¹H-NMR, and EI-MS, and then screened against acetylcholinesterase, butylcholinesterase, and lipoxygenase enzyme, and were found to be potent inhibitors of butyrylcholinesterase alone.

Este trabalho apresenta a síntese de uma série de derivados da 2-fenetidina N-substituídos. Primeiro, a reação da 2-fenetidina (1) com cloreto de benzenossulfonila (2) conduziu à N-(2-etoxifenil)benzenossulfonamida (3) que, após tratamento com hidreto de sódio e haletos de alquila (4a-g), originou novas sulfonamidas (5a-g). Em segundo lugar, a reação da fenetidina com cloreto de benzoíla (6) e cloreto de acetila (8) conduziu, respectivamente, à N-benzoilfenetidina (7) e N-acetilfenetidina (9). A caracterização destes derivados fez-se por IV, ¹H-RMN e EM-IE. Procedeu-se à avaliação da atividade inibidora destes compostos em relação às enzimas acetilcolinesterase, butirilcolinesterase e lipoxigenase. No entanto, apenas revelaram atividade inibidora da butirilcolinesterase.