Synthesis, Structure, and Antibacterial Activity of Novel 5-Arylpyrazole Derivatives

2008 ◽  
Vol 61 (3) ◽  
pp. 223 ◽  
Author(s):  
Xin-Hua Liu ◽  
Peng-Cheng Lv ◽  
Bo Li ◽  
Hai-Liang Zhu ◽  
Bao-An Song

A series of novel 1-(acetyl,carboxamide,carbothioamide)substituted-5-(substituted-phenyl)-3-methy-4,5-dihydropyrazole derivatives have been synthesized and characterized by 1H NMR, IR, ESI-MS, and elemental analysis. Compounds 6h and 6q were further characterized by single crystal X-ray structural analysis. All of the compounds have been screened for their antibacterial potential in vitro against Bacillus subtilis ATCC 6633, Escherichia coli ATCC 35218, Pseudomonas fluorescens ATCC 13525, and Staphylococcus aureus ATCC 6538. Among the tested compounds, some of them display significant activity against the tested strains, and compounds 5ac and 6h show potent activity with a minimum inhibitory concentration value of 1.562 μg mL–1 against B. subtilis ATCC 6633, which is comparable to the positive control penicillin. Structure–effect relationships are also discussed based on the experimental data.

Author(s):  
Dilek Demirezen-Yilmaz ◽  
Fatih Doğan Koca ◽  
Nurhan Ertaş-Onmaz

In this study, the powder of Allcemilla vulgaris was used in the sythesis of silver and zinc nanoparticle. Biologically synthesized nanoparticles were characterized using Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, X-ray diffraction (XRD) and Zeta potential and then evaluated for antibacterial potential using micro dilution broth method. The minimum inhibitory concentration values of AgNP were 4.25 µg/mL and 6.64 µg/ mL for Escherichia coli O157:H7 and Staphylococcus aureus, respectively. Similarly, the MIC values of ZnNP were 3.32 µg/mL and 6.25 µg/mL, respectively for Escherichia coli O157:H7 and Staphylococcus aureus.


2014 ◽  
Vol 58 (10) ◽  
pp. 6044-6055 ◽  
Author(s):  
Tanira M. Bastos ◽  
Marília I. F. Barbosa ◽  
Monize M. da Silva ◽  
José W. da C. Júnior ◽  
Cássio S. Meira ◽  
...  

ABSTRACTcis-[RuCl(NO2)(dppb)(5,5′-mebipy)] (complex 1),cis-[Ru(NO2)2(dppb)(5,5′-mebipy)] (complex 2),ct-[RuCl(NO)(dppb)(5,5′-mebipy)](PF6)2(complex 3), andcc-[RuCl(NO)(dppb)(5,5′-mebipy)](PF6)2(complex 4), where 5,5′-mebipy is 5,5′-dimethyl-2,2′-bipyridine and dppb is 1,4-bis(diphenylphosphino)butane, were synthesized and characterized. The structure of complex 2 was determined by X-ray crystallography. These complexes exhibited a higher anti-Trypanosoma cruziactivity than benznidazole, the current antiparasitic drug. Complex 3 was the most potent, displaying a 50% effective concentration (EC50) of 2.1 ± 0.6 μM against trypomastigotes and a 50% inhibitory concentration (IC50) of 1.3 ± 0.2 μM against amastigotes, while it displayed a 50% cytotoxic concentration (CC50) of 51.4 ± 0.2 μM in macrophages. It was observed that the nitrosyl complex 3, but not its analog lacking the nitrosyl group, releases nitric oxide into parasite cells. This release has a diminished effect on the trypanosomal protease cruzain but induces substantial parasite autophagy, which is followed by a series of irreversible morphological impairments to the parasites and finally results in cell death by necrosis. In infected mice, orally administered complex 3 (five times at a dose of 75 μmol/kg of body weight) reduced blood parasitemia and increased the survival rate of the mice. Combination index analysis of complex 3 indicated that itsin vitroactivity against trypomastigotes is synergic with benznidazole. In addition, drug combination enhanced efficacy in infected mice, suggesting that ruthenium-nitrosyl complexes are potential constituents for drug combinations.


2021 ◽  
Vol 50 (2) ◽  
pp. 219-226
Author(s):  
Abdul Haq ◽  
Alam Khan ◽  
Zulfiqar Ali Malik ◽  
Mushtaq Ahmed ◽  
Samiullah Khan ◽  
...  

Antimicrobial activities of deoiled seed kernel (mechanically pressed), fruit coat and seed coat of Jatropha curcas Linn. collected from two regions (Bannu and Peshawar) of Pakistan were investigated. The antimicrobial activities were carried out against Klebsiella pneumoniae (ATCC 43816), Escherichia coli (ATCC 10536), Staphylococcus aureus (ATCC 6538), Bacillus subtilis (ATCC 6633) and two clinical fungal isolates Aspergillus fumigatus and Candida albicans using agar well diffusion method. The antibacterial activities of Peshawar sample were found to be higher than Bannu, against selected strains. While antifungal activities of both samples were similar. Highest zone of inhibition 31.5 ± 0.7 mm was exhibited by n-hexane extract of deoiled seed kernel of Peshawar sample against Bacillus subtilis (ATCC 6633). The minimum inhibitory concentration of ethanolic extracts of deoiled seed kernel and seed coat of Peshawar sample was 31.25 - 25 mg/ml. Whereas, minimum inhibitory concentration of ethanolic and n-hexane extracts of Bannu sample was 62.5 - 125 mg/ml. The results suggested that antimicrobial potential of J. curcas Linn. varied with geographical distribution. The investigation of different varieties of medicinal plants belonging to the same species will greatly enhance the chances of best pharmaceuticals discovery. Bangladesh J. Bot. 50(2): 219-226, 2021 (June)


Author(s):  
Gautam Shiv Shankar ◽  
M Navneet ◽  
Kumar Sanjay ◽  
M Prabhat

The aim of present study was to evaluate the antibacterial potential of various extracts (petroleum ether, acetone, methanol and aqueous) of Nepeta ciliaris against selected respiratory tract pathogens. The extracts from the aerial parts of N. ciliaris at concentration of 200 mg/ml were screened against three gram-positive (Staphylococcus aureus MTCC 1144, Streptococcus pneumoniae MTCC 655 and Streptococcus pyogenes MTCC 442) and one gram-negative (Pseudomonas aeruginosa MTCC 2474) bacterial pathogens. The agar well diffusion method was adopted to examine antibacterial and minimum inhibitory concentration (MIC) values of most effective extracts against the susceptible bacteria. Erythromycin was used as positive control to determine the sensitivity of the strains. Out of the four bacterial species tested, S. pneumoniae was the most susceptible. The acetone extract exhibited maximum activity against all the tested microorganisms while methanol extract showed activity against P. aeruginosa. The MIC values ranged from 40 to 50 mg/ml for all the organisms. The N. ciliaris is potentially a good source of antimicrobial agents. DOI: http://dx.doi.org/10.3126/kuset.v8i1.6049 KUSET 2012; 8(1): 100-103


Author(s):  
Mihaela DUMITRU ◽  
Mihaela HĂBEANU ◽  
Cristina TABUC ◽  
Ștefana JURCOANE

This study aimed to evaluate some probiotic properties of Bacillus subtilis ATCC 6051a. The phenotypic profile, resistance to pH by simulated gastric juice (pH 2 and 3), bile salts by simulated intestinal fluid, survivability (%), heat and antibiotics tolerance were investigated. The strain is a Gram-positive, rod-shaped bacteria, arranged in short chains or in small irregular pairs with the ability to produce spores. Good viability at pH 2 and 3, with a survival of more than ≥80%, was found. In the presence of bile salts 0.3%, over 4 h, the strain exhibited a survival ≥85%. At 80°C, for 120 min., the strain showed good growth (9.04 log CFU/ml). Results were sensitive to most antibiotics, with a highly susceptible (between 16 – 25 mm) to erythromycin, clindamycin, amoxicillin, chloramphenicol, ciprofloxacin, amikacin and kanamycin. The strain was found to be sensitive to vancomycin, gentamicin, and tetracycline. The present research demonstrated that Bacillus subtilis ATCC 6051a can survive under gastrointestinal conditions, which involves them to future in vitro and in vivo probiotic studies.


2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Karen Tatiana Chávez Arteaga ◽  
Jefferson Javier Guato Molina ◽  
Jorge Luis Rodríguez Acosta ◽  
Ángel Virgilio Cedeño Moreira ◽  
Ricardo Fernando Romero Meza ◽  
...  

El empleo de bio-controladores en la agricultura beneficia los aspectos fisiológicos en plantas, a diferencia de la constante aplicación de pesticidas en el cultivo del banano ha ocasionado la pérdida de la sensibilidad en M. fijiensis, reduciendo la microbiota del suelo. El objetivo se enfocó en caracterizar el potencial antagónico de las PGPR en inhibición de germinación de ascósporas y desarrollo micelial de M. fijiensis. Se realizaron cultivos monospóricos de M. fijiensis e identificado por PCR. Se evaluaron los extractos celulares de Pseudomonas putida PB3-6, Klebsiella variicola BO3-4, Enterobacter asburiae BA4-19, Serratia marcescens PM3-8, Enterobacter asburiae PM3-14, Pseudomonas protegens CHA0, Pseudomonas fluorescens WCS417, Pseudomonas veronii R4 y Bacillus subtilis ATCC 5540 para sus evaluaciones antagonistas: a) Inhibición del tubo germinativo de las ascósporas al 2% y b) Desarrollo micelial al (2 y 10 %). La PCR empleado en la identificación de M. fijiensis se confirma el producto de amplificación de 1018 pb. El factor antagónico de los extractos celulares al 2 % de PM3-14 y CHA0 inhibe sobre el 80 % al desarrollo de los tubos germinativos. La inhibición al desarrollo micelial del extracto celular al 2 %, de CHA0 logró una efectividad del 54 % y las cepas (PM3-8, PM3-14 y BA4-19) con (32, 26 y 26 %). Al 10 % del extracto de la cepa PM3-8 inhibe el desarrollo micelial con niveles de turbidez de 0,47 (OD600nm). El empleo de estos bio-controladores en la agricultura ofrecerá una alternativa para beneficiar en la reducción del uso de agroquímicos


Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1339 ◽  
Author(s):  
Islam H. El Azab ◽  
Nadia A.A. Elkanzi

A series of 34 new pyrimido[2,1-c][1,2,4]triazine-3,4-diones were synthesized and fully characterized using IR, NMR, MS, and microanalytical analysis. In vitro investigation of 12 compounds of this series revealed promising antimicrobial activity of the conjugates 15a and 15f–j that were tagged with electron-withdrawing groups, with sensitivities ranging from 77% to as high as 100% of the positive control. The investigation of antimicrobial activity included Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 6535, Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 8739 (EC), and fungal strains Candida albicans ATCC 10231 and Aspergillus brasiliensis ATCC 16404.


Marine Drugs ◽  
2019 ◽  
Vol 17 (6) ◽  
pp. 322 ◽  
Author(s):  
Yao-Yao Zheng ◽  
Zhao-Yang Liang ◽  
Nan-Xing Shen ◽  
Wen-Long Liu ◽  
Xiao-Jian Zhou ◽  
...  

Three novel monomeric naphtho-γ-pyrones, peninaphones A–C (compounds 1–3), along with two known bis-naphtho-γ-pyrones (compounds 4 and 5) were isolated from mangrove rhizosphere soil-derived fungus Penicillium sp. HK1-22. The absolute configurations of compounds 1 and 2 were determined by electronic circular dichroism (ECD) spectra, and the structure of compound 3 was confirmed by single-crystal X-ray diffraction analysis. Compounds 4 and 5 are a pair of hindered rotation isomers. A hypothetical biosynthetic pathway for the isolated monomeric and dimeric naphtho-γ-pyrones is also discussed in this study. Compounds 1–3 showed antibacterial activity against Staphylococcus aureus (ATCC 43300, 33591, 29213, and 25923) with minimum inhibitory concentration (MIC) values in the range of 12.5–50 μg/mL. Compound 3 exhibited significant activity against the rice sheath blight pathogen Rhizoctonia solani.


2002 ◽  
Vol 55 (3) ◽  
pp. 229 ◽  
Author(s):  
Dachriyanus Salni ◽  
M. V. Sargent ◽  
B. W. Skelton ◽  
I. Soediro ◽  
M. Sutisna ◽  
...  

The ethyl acetate extract of the leaves of Rhodomyrtus tomentosa (Ait.) Hassk. yielded rhodomyrtone (5) [6,8-dihydroxy-2,2,4,4-tetramethyl-7-(3-methyl-1-oxobutyl)-9-(2-methylpropyl)-4,9-dihydro-1H-xanthene-1,3(2H)-di-one] which had significant activity against Escherichia coli and Staphylococcus aureus. The structural elucidation followed from spectroscopic evidence and from a single-crystal X-ray structural determination.


Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3608 ◽  
Author(s):  
Pedro Fong ◽  
Chon-Hou Hao ◽  
Chi-Cheng Io ◽  
Pou-Io Sin ◽  
Li-Rong Meng

Helicobacter pylori infection is a WHO class 1 carcinogenic factor of gastric adenocarcinoma. In the past decades, many studies have demonstrated the increasing trend of antibiotic resistance and pointed out the necessity of new effective treatment. This study was aimed at identifying phytochemicals that can inhibit H. pylori and possibly serve as adjuvant treatments. Here, in silico molecular docking and drug-like properties analyses were performed to identify potential inhibitors of urease, shikimate kinase and aspartate-semialdehyde dehydrogenase. These three enzymes are targets of the treatment of H. pylori. Susceptibility and synergistic testing were performed on the selected phytochemicals and the positive control antibiotic, amoxicillin. The in-silico study revealed that oroxindin, rosmarinic acid and verbascoside are inhibitors of urease, shikimate kinase and aspartate-semialdehyde dehydrogenase, respectively, in which, oroxindin has the highest potency against H. pylori, indicated by a minimum inhibitory concentration (MIC) value of 50 μg/mL. A combination of oroxindin and amoxicillin demonstrated additive effects against H. pylori, as indicated by a fractional inhibitory concentration (FIC) value of 0.75. This study identified phytochemicals that deserve further investigation for the development of adjuvant therapeutic agents to current antibiotics against H. pylori.


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