scholarly journals The SYNTHESIS, SCREENING OF NOVEL 1-SUBSTITUTED-3-(4-OXO-2-PHENYLQUINAZOLIN-3(4H)-YL) UREA AND THIOUREA ANALOGUES AS POTENT ANTIBACTERIALS

Author(s):  
SANDHYA R. DHOKALE ◽  
SNEHAL R. THAKAR ◽  
DEEPALI A. BANSODE ◽  
KAKASAHEB R. MAHADIK

Objective: The proposed study is an attempt to determine antibacterial activity of synthesized novel 1-substituted-3-(4-oxo-2-phenylquinazolin-3(4H)-yl) urea and thiourea analogues as potent antibacterials against S. aureus and E. coli bacteria. Methods: The present study reports new series of 1-substituted-3-(4-oxo-2-phenylquinazolin-3(4H)-yl) urea and thiourea derivatives as potent antibacterial agents. Reagents used in the present study were of synthetic grade and solvents were used after distillation. Novel quinazolinone analogues were synthesized by considering substitution pattern, characterization of the synthesized analogues was performed using various techniques like Thin layer chromatography, Melting point, Infrared spectroscopy, Proton NMR spectrometry and Mass spectrometry. TLC of the synthesized analogues was carried out by using (toluene: methanol in the ratio 2:1), melting point was found by open capillary method, IR spectrum was recorded on JASCO V-530, 1H NMR was recorded on Bruker Avance Spectrometer and Mass spectra were obtained from G6460A, triple quadrupole/MS/MS system. In vitro antibacterial activity was performed against S. aureus and E. coli. Results: Six derivatives of quinazolinone analogues were synthesized. The structures of 1-substituted-3-(4-oxo-2-phenylquinazolin-3(4H)-yl) urea and thiourea derivatives were confirmed by physical and spectral analysis. Synthesized molecules showed Rf of 0.45-0.80 in toluene: methanol mobile phase, melting point was carried out by open capillary method and were in range of 90-210 ° C, IR spectrum was recorded in range of 14000-400 cm-1and showed characteristic peaks of NH and of C-O-NH, 1H NMR of the compounds was distinct to confirm structures with delta values in the range of 7.53-11.960, Mass spectra proved parent peaks of synthesized compounds confirming molecular weight. The compounds were assayed for antibacterial activity against S. aureus and E. coli using ciprofloxacin as standard. The synthesized analogues have shown good yield and comparable antibacterial. Conclusion: The present study delivers a convenient and efficient protocol for the quinazolinone analogues synthesis.

2015 ◽  
Vol 12 (3) ◽  
pp. 546-554
Author(s):  
Baghdad Science Journal

New series of Schiff bases 2(a-j) and corresponding beta-lactam derivatives 3(a-j) were synthesized from cefalexin (1) as starting material. The compound (1) was reacted with different aldehydes and ketones to give Schiff bases derivatives 2(a-j). The synthesized Schiff bases were cyclized by chloroacetyl chloride in the presence of triethylamine to form beta-lactam derivatives 3(a-j). The compounds were characterized by deremination melting point, FT-IR and 1H NMR. The beta-lactam derivatives were screened in vitro antibacterial against some bacterial species


2016 ◽  
Vol 5 (04) ◽  
pp. 4512
Author(s):  
Jackie K. Obey ◽  
Anthoney Swamy T* ◽  
Lasiti Timothy ◽  
Makani Rachel

The determination of the antibacterial activity (zone of inhibition) and minimum inhibitory concentration of medicinal plants a crucial step in drug development. In this study, the antibacterial activity and minimum inhibitory concentration of the ethanol extract of Myrsine africana were determined for Escherichia coli, Bacillus cereus, Staphylococcus epidermidis and Streptococcus pneumoniae. The zones of inhibition (mm±S.E) of 500mg/ml of M. africana ethanol extract were 22.00± 0.00 for E. coli,20.33 ±0.33 for B. cereus,25.00± 0.00 for S. epidermidis and 18. 17±0.17 for S. pneumoniae. The minimum inhibitory concentration(MIC) is the minimum dose required to inhibit growth a microorganism. Upon further double dilution of the 500mg/ml of M. africana extract, MIC was obtained for each organism. The MIC for E. coli, B. cereus, S. epidermidis and S. pneumoniae were 7.81mg/ml, 7.81mg/ml, 15.63mg/ml and 15.63mg/ml respectively. Crude extracts are considered active when they inhibit microorganisms with zones of inhibition of 8mm and above. Therefore, this study has shown that the ethanol extract of M. africana can control the growth of the four organisms tested.


2021 ◽  
pp. 0887302X2110094
Author(s):  
V. Mamtha ◽  
H. N. Narasimha Murthy ◽  
V. Pujith Raj ◽  
Prashantha Tejas ◽  
C. S. Puneet ◽  
...  

Antibacterial activity and fire retardation are equally desired for protective clothing. For achieving this, AgNP and MgO are independently researched as nanofillers in Polyurethane based electrospun nanofibers and their synergistic effect is scarcely addressed. This article reports synthesis and characterization of MgO of 70.01 nm and AgNP of 51 to 76 nm by solution combustion and hydrothermal routes respectively and their incorporation in electrospinning of Polyurethane. Flow rate 1 ml/hr, applied voltage 13 kV, tip to collector distance 15 cm were adopted for the electrospinning. Nanofibers of 65 nm were obtained for PU/MgO (3 wt. %) and 106 nm for PU/MgO (3 wt. %)/Ag (1 wt. %). Addition of MgO increased the melting point, after flame time and afterglow time. Incorporation of AgNP improved antibacterial activity. PU/MgO/Ag (2 wt. %) exhibited zone of inhibition of 2.1 cm and 3 cm against E. Coli and S. Aureus, respectively.


2021 ◽  
Vol 74 (9) ◽  
pp. 2109-2111
Author(s):  
Evheniia A. Shtaniuk ◽  
Oleksandra O. Vovk ◽  
Larisa V. Krasnikova ◽  
Yuliia I. Polyvianna ◽  
Tetiana I. Kovalenko

The aim: Study of antibacterial activity of the preparations, containing antiseptic dioxidine and antibiotic levofloxacin in vitro on standard strains of main optional-anaerobic pathogens of purulent-inflammatory processes of surgical wounds S. aureus, E. coli, P. aeruginosa and definition of more effective ones on them. Materials and methods: Solutions of dioxidine 1.2 %, dioxidine 1.2% with decamethaxin, Dioxisole, water soluble ointment with dioxidine 1.2% and levofloxacin 0.1% with decamethaxin were used in experiment. Antibacterial activity was studied on standard strains of S. aureus АТСС 25923, E. coli АТСС 25922, P. aeruginosa АТСС 27853. Distinguishing and identification of pure cultures of bacteria was done according to generally accepted microbiological methods. Determination of purulent-inflammatory processes pathogens sensitivity was done by disco-diffuse method on Mueller-Hinton medium. Antibacterial activity of solutions and ointments was studied with the help of agar diffusion method (“well” method) according to methodic recommendations. Each investigation was repeated 6 times. Method of variation statistics was used for the research results analysis. Results: All antibacterial preparations under study are effective and highly effective on S. aureus АТСС 25923, E. coli АТСС 25922, P. aeruginosa АТСС 27853. Solution with 1.2 % dioxidine with decamethaxin and ointment with 0.1 % levofloxacin and decamethaxin have larger growth retardation zones towards S. aureus and P. aeruginosa. E. coli strains are more sensitive to the solution of Dioxisole and ointment with 1.2 % dioxidine. Conclusions: All strains are sensitive, most of them are highly sensitive, up to 5 antibacterial preparations under study in vitro.


2019 ◽  
Vol 24 ◽  
pp. 2515690X1988627 ◽  
Author(s):  
Mekonnen Sisay ◽  
Negussie Bussa ◽  
Tigist Gashaw ◽  
Getnet Mengistu

Medicinal plants are targeted in the search for new antimicrobial agents. Nowadays, there is an alarmingly increasing antimicrobial resistance to available agents with a very slow development of new antimicrobials. It is, therefore, necessary to extensively search for new agents based on the traditional use of herbal medicines as potential source. The antibacterial activity of 80% methanol extracts of the leaves of Verbena officinalis (Vo-80ME), Myrtus communis (Mc-80ME), and Melilotus elegans (Me-80ME) was tested against 6 bacterial isolates using agar well diffusion technique. In each extract, 3 concentrations of 10, 20, and 40 mg/well were tested for each bacterium. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were also determined. Vo-80ME and Mc-80ME exhibited promising antibacterial activity against Staphylococcus aureus with the highest zone of inhibition being 18.67 and 26.16 mm, respectively at concentration of 40 mg/well. Regarding gram-negative bacteria, Vo-80ME exhibited an appreciable activity against Escherichia coli and Salmonella typhi. Mc-80ME displayed remarkable activity against all isolates including Pseudomonas aeruginosa with the maximum zone of inhibition being 22.83 mm. Me-80ME exhibited better antibacterial activity against E coli, but its secondary metabolites had little or no activity against other gram-negative isolates. The MIC values of Vo-80ME ranged from 0.16 to 4.00 mg/mL. The lowest MIC was observed in Mc-80ME, with the value being 0.032 mg/mL. Mc-80ME had bactericidal activity against all tested bacterial isolates. Mc-80ME showed remarkable zone of inhibitions in all tested bacterial isolates. Besides, Vo-80ME showed good antibacterial activity against S aureus, E coli, and S typhi. Conversely, Me-80ME has shown good activity against E coli only. Generally, M communis L and V officinalis have good MIC and MBC results.


2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Naheed Zafar ◽  
Bushra Uzair ◽  
Muhammad Bilal Khan Niazi ◽  
Shamaila Sajjad ◽  
Ghufrana Samin ◽  
...  

Treatment of pandrug resistant (PDR) Escherichia coli strain is the leading causative agent of bovine mastitis worldwide. Hence, becoming a potential threat to veterinary and public health. Therefore, to control the infection new nontoxic, biocompatible antimicrobial formulation with enhanced antibacterial activity is massively required. Current study was planned to synthesize chitosan coated titanium dioxide nanoparticles (CS-NPs coated TiO2). Coating was being done by chitosan nanoparticles (CS-NPs) using ionic gelation method. Aqueous solution of Moringa concanensis leaf extract was used to synthesize titanium dioxide nanoparticles (TiO2 NPs). The synthesized nanoformulations were characterized by using XRD, SEM, and FTIR. X-ray diffraction (XRD) analysis indicated the crystalline phase of TiO2 NPs and CS-NPs coated TiO2 NPs. Scanning Electron Microscopy (SEM) confirmed spherical shaped nanoparticles size of chitosan NPs ranging from 19–25 nm and TiO2 NPs 35–50 nm. Thesize of CS-NPs coated TiO2 NPs was in the range of 65–75 nm. The UV-Vis Spectra and band gap values illustrated the red shift in CS-NPs coated TiO2 NPs. Fourier transform infrared (FTIR) spectroscopy confirmed the linkages between TiO2 NPs and chitosan biopolymer, Zeta potential confirmed the stability of CS-NPs coated TiO2 NPs by showing 95 mV peak value. In-vitro antibacterial activity of CS-NPs coated TiO2 NPs and Uncoated TiO2 NPs was evaluated by disc diffusion method against PDR strain of E. coli isolated from mastitic milk samples. The antibacterial activity of all the synthesized nanoformulations were noted and highest antibacterial activity was shown by CS-NPs coated TiO2-NPs against pandrug resistant (PDR) E. coli strain with the prominent zone of inhibition of 23 mm. Morphological changes of E. coli cells after the treatment with MIC concentration (0.78 μg/ml) of CS-NPs coated TiO2 NPs were studied by transmission electron microscopy TEM showedrigorous morphological defectand has distorted the general appearance of the E. coli cells. Cytotoxicity (HepG2 cell line) and hemolytic (human blood) studies confirmed nontoxic/biocompatible nature of CS-NPs coated biologically synthesized TiO2 NPs. The results suggested that biologically synthesized and surface modified TiO2 NPs by mucoadhesive polysaccharides (e.g. chitosan) coating would be an effective and non-toxic alternative therapeutic agent to be used in livestock industry to control drug resistant veterinary pathogens.


2020 ◽  
Vol 32 (4) ◽  
pp. 896-900
Author(s):  
M. Idrees ◽  
Y.G. Bodkhe ◽  
N.J. Siddiqui ◽  
S.S. Kola

A series of 5-(benzofuran-2-yl)-N-(3-chloro-4-(2-(p-tolyloxy) substituted quinolin-3-yl)-2-oxoazetidin-1-yl)-1-phenyl-1H-pyrazole-3-carboxamide derivatives (4a-f) were synthesized with excellent yields by cyclocondensation reaction of 5-(benzofuran-2-yl)-N′-(2-(p-tolyloxy) substituted quinolin-3-yl)methylene)-1-phenyl-1H-pyrazole-3-carbohydrazide (3a-f) with chloroacetyl chloride in presence of triethylamine in DMF. One pot condensation of 5-(benzofuran-2-yl)-1-phenyl-1H-pyrazole-3-carbohydrazide (1) with 2-(p-tolyloxy) substituted quinoline-3-carbaldehyde (2a-f) in ethanol solvent in presence of catalytic amount of acetic acid gave intermediate compounds (3a-f). The structures of newly synthesized compounds have been substantiated through elemental analysis and spectral studies viz. 1H NMR, 13C NMR, IR and mass spectra. All the synthesized compounds were screened for their in vitro antibacterial activity against pathogenic bacteria such as S. aureus and E. coli at different concentrations.


Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2766 ◽  
Author(s):  
Heba E. Hashem ◽  
Abd El-Galil E. Amr ◽  
Eman S. Nossier ◽  
Elsayed A. Elsayed ◽  
Eman M. Azmy

To develop new antimicrobial agents, a series of novel thiourea derivatives incorporated with different moieties 2–13 was designed and synthesized and their biological activities were evaluated. Compounds 7a, 7b and 8 exhibited excellent antimicrobial activity against all Gram-positive and Gram-negative bacteria, and the fungal Aspergillus flavus with minimum inhibitory concentration (MIC) values ranged from 0.95 ± 0.22 to 3.25 ± 1.00 μg/mL. Furthermore, cytotoxicity studies against MCF-7 cells revealed that compounds 7a and 7b were the most potent with IC50 values of 10.17 ± 0.65 and 11.59 ± 0.59 μM, respectively. On the other hand, the tested compounds were less toxic against normal kidney epithelial cell lines (Vero cells). The in vitro enzyme inhibition assay of 8 displayed excellent inhibitory activity against Escherichia coli DNA B gyrase and moderate one against E. coli Topoisomerase IV (IC50 = 0.33 ± 1.25 and 19.72 ± 1.00 µM, respectively) in comparison with novobiocin (IC50 values 0.28 ± 1.45 and 10.65 ± 1.02 µM, respectively). Finally, the molecular docking was done to position compound 8 into the E. coli DNA B and Topoisomerase IV active pockets to explore the probable binding conformation. In summary, compound 8 may serve as a potential dual E. coli DNA B and Topoisomerase IV inhibitor.


Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2126 ◽  
Author(s):  
Alla V. Lipeeva ◽  
Danila O. Zakharov ◽  
Liubov G. Burova ◽  
Tatyana S. Frolova ◽  
Dmitry S. Baev ◽  
...  

Synthesis of 1,2,3-triazole-substituted coumarins and also 1,2,3-triazolyl or 1,2,3-triazolylalk-1-inyl-linked coumarin-2,3-furocoumarin hybrids was performed by employing the cross-coupling and copper catalyzed azide-alkyne cycloaddition reaction approaches. The synthesized compounds were evaluated for their in vitro antibacterial activity against Staphylococcus aureus, Bacillius subtilis, Actinomyces viscosus and Escherichia coli bacterial strains. Coumarin-benzoic acid hybrids 4с, 42с and 3-((4-acetylamino-3-(methoxycarbonyl)phenyl)ethynyl)coumarin (29) showed promising activity against S. aureus strains, and the 1,2,3-triazolyloct-1-inyl linked coumarin-2,3-furocoumarin hybrid 37c was endowed with high selectivity against B. subtilis and E. coli species. The in vitro antibacterial activity of 4с, 29, 37c and 42с can potentially be compared with that of a number of modern antibiotic drugs used in the clinic, suggesting promising prospects for further research. A detailed study of the molecular interactions with the targeted protein MurB was performed using docking simulations and the obtained results are quite promising.


1997 ◽  
Vol 41 (5) ◽  
pp. 927-930 ◽  
Author(s):  
L Aguilar ◽  
M J Giménez ◽  
J Costa ◽  
R Dal-Ré ◽  
J Prieto

The prediction of urine antibacterial activity from pharmacological and microbiological parameters was assessed by using experimental urine levels and urine bactericidal titers determined up to 72 h after a 400-mg single dose of two quinolones in a phase I study. The area under the bactericidal curve (AUBC) was accurately predicted for norfloxacin but significantly (P < 0.001) underestimated for rufloxacin (actual value was four times higher than the predicted value against Escherichia coli and two times higher against Staphylococcus aureus). In vitro susceptibility differences between the two strains predicted the ex vivo AUBC differences for norfloxacin but not for rufloxacin, where ex vivo differences were greater than expected. Urine bactericidal titers for up to 72 h were accurately predicted for norfloxacin against E. coli and S. aureus and for rufloxacin against S. aureus, but experimental activity for up to 48 h was four times higher (P < 0.001) than the predicted activity for rufloxacin against E. coli. In the case of norfloxacin, the duration of adequate urine antibacterial activity against S. aureus was overestimated. Inaccurate estimations of ex vivo antibacterial activity of a suspected active metabolite (as with rufloxacin) when an adequate cutoff is not established may have dosing implications.


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