scholarly journals SYNTHESIS, MOLECULAR BIOINFORMATICS MODELLING, AND ANTIMICROBIAL EVALUATION OF SOME NOVEL OXADIAZOLE FLUOROQUINOLONE DERIVATIVES

Author(s):  
NAWAZ MOHAMMED KHAN ◽  
PAWAN KUMAR ◽  
HEMANTH SUDHEER KUMAR K ◽  
BHARATH RATHNA KUMAR P

Objective: The present study envisages a series of oxadiazole fluoroquinolone derivatives that were synthesized (D1–D12) with added derivatives such as phenyl, aminophenyl, amino hydroxyphenyl along with cyclopropyl, ethyl, piperazine, and imidazole. Methods: All of the newly produced molecules were characterized by infrared, 1H nuclear magnetic resonance, mass spectrometry, and elemental analysis technique and screened for docking stimulation to find out binding modes of synthesized derivatives with 3FV5, 5IMW, and 5ESE and evaluated for in vitro antimicrobial activity. Results: From this study, it was found that the compound D8 showed good antibacterial activity against Gram-positive (Staphylococcus aureus), compound D9 showed good antibacterial activity against Gram-negative (Escherichia coli), and compound D3 showed good antifungal activity against fungi (Saccharomyces cerevisiae) in comparison with standard drugs (Ciprofloxacin and fluconazole). The zone of inhibition and minimum inhibitory concentration studies was performed on synthesized compounds. Conclusion: The analogs of oxadiazole flouroquinolone are suggested to be potent inhibitors with sufficient scope for further exploration.

Author(s):  
Hemanth K Sudheer Kumar ◽  
Parameshwar H

Objective: The present study envisage a series of sparfloxacin derivatives were synthesized (Q1-Q10) with added derivatives such as aminomethyl benzenesulfenyl, methyl (methylamino)benzenesulfenyl, amino methyl benzoyl chloride, nitromethyl benzoyl chloride, dimethyl phenylamino, methoxymethyl phenylamino, dimethyl oxopyrazol, methyl dioxopyrrolidine, methyl oxopyrrolidine, and N-Boc amino methyl methylpyrrolidine through N-Piperzinyl linkage.Methods: All the newly synthesized compounds were characterized by infrared,1H nuclear magnetic resonance, mass spectrometry, and elemental analysis technique, screened for docking stimulation to find out binding modes of synthesized derivatives with 3FV5 and 3IMW, and evaluated for in vitro antimicrobial activity.Results: From this study, it was found that the compound Q5 showed good antibacterial activity against Gram-positive (Staphylococcus aureus) and compound Q4 showed good antibacterial activity against Gram-negative (Escherichia coli) in comparison with standard drugs (ciprofloxacin and sparfloxacin). The zone of inhibition and minimum inhibitory concentrations studies performed to synthesized compounds. The correlation between experimental data (minimum inhibitory concentrations) and docking score suggests that penetration for docking simulation is good to mild in reproducing experimental orientation of these synthesized compounds.Conclusion: The analogs of sparfloxacin are suggested to be potent inhibitors with sufficient scope for further exploration.


2019 ◽  
Vol 16 (4) ◽  
pp. 392-400 ◽  
Author(s):  
Göknil Pelin Coşkun ◽  
Teodora Djikic ◽  
Sadık Kalaycı ◽  
Kemal Yelekçi ◽  
Fikrettin Şahin ◽  
...  

Background:The main factor for the prolongation of the ulcer treatment in the gastrointestinal system would be Helicobacter pylori infection, which can possibly lead to gastrointestinal cancer. Triple therapy is the treatment of choice by today's standards. However, observed resistance among the bacterial strains can make the situation even worse. Therefore, there is a need to discover new targeted antibacterial therapy in order to make success in the eradication of H. pylori infections.Methods:The targeted therapy rule is to identify the related macromolecules that are responsible for the survival of the bacteria. Thus, 2-[(2',4'-difluoro-4-hydroxybiphenyl-3-yl)carbonyl]-N- (substituted)hydrazinocarbothioamide (3-13) and 5-(2',4'-difluoro-4-hydroxybiphenyl-3-yl)-4- (substituted)-2,4-dihydro-3H-1,2,4-triazole-3-thiones (14-17) were synthesized and evaluated for antibacterial activity in vitro against H. pylori.Results:All of the tested compounds showed remarkable antibacterial activity compared to the standard drugs (Ornidazole, Metronidazole, Nitrimidazin and Clarithromycin). Compounds 4 and 13 showed activity as 2µg/ml MIC value.Conclusion:In addition, we have investigated binding modes and energy of the compounds 4 and 13 on urease enzyme active by using the molecular docking tools.


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.


Author(s):  
TITTY SULIANTI ◽  
NILAKESUMA DJAUHARI ◽  
BAMBANG NURSASONGKO

Objective: The aim is to compare the antimicrobial effects of papain and Papacarie with dilution and diffusion tests.Methods: There were two treatment groups and one Group control. The treatment group received papain and Papacarie, and the control groupreceived chlorhexidine, in five liquids with different concentrations of 0.5%, 0.25%, 0.125%, 0.0625%, and 0.03%. The dilution and diffusion testswere used to determine the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and zone of inhibition for eachtreatment material.Results: MICs of papain and Papacarie were 12.5%, indicating that at a concentration of 12.5%, the material can inhibit the growth of Streptococcusmutans. Papain does not have an MBC value but the Papacarie has an MBC at 25%, which indicating that at a concentration of 25%, Papacarie hasbactericidal effects on S. mutans. The zone of inhibition of papain was lower than Papacarie.Conclusion: Based on chemomechanical caries removal materials, the antimicrobial effects of Papacarie were better than those of papain.


2011 ◽  
Vol 4 (1) ◽  
pp. 22-25 ◽  
Author(s):  
M Bashir ◽  
I Yusuf ◽  
AS Kutama

Five traditional herbal preparations were sampled between May-June, 2009 in Kano. The samples were investigated for invitro antibacterial activities against clinical isolates of Staphylococcus aureus. Likewise, phytochemical screening tests were conducted to determine some of the phytochemicals present in the ethanolic and water extracts of the samples. Various concentrations of the extracts were prepared using serial doubling dilutions (5000=l/ml, 2500=g/ml, 1250=g/ml, 625=g/ml and 312.5=g/ml). All the test extracts showed slight antibacterial activity against the test organism, with ethanolic extract of sample E having the highest zone diameter of inhibition, while sample H had the lowest diameter of inhibition. The standard antibiotic disc (Gentamicin) had demonstrated the highest activity on the test organisms. The results of the Phytochemical screening revealed the presence of steroid in all the samples, tannin in samples A, C, D and E, reducing sugars in sample A, D and E respectively. The result of the minimum inhibitory concentration (MIC) was found to be above 312.5=g/ml for samples C, D and E. Keywords: Staphylococcus aureus, Herbal preparations, antibacterial activity, Phytochemical screening and minimum inhibitory concentration.


2019 ◽  
Vol 10 (2) ◽  
pp. 1049-1053 ◽  
Author(s):  
Geetha RV ◽  
John Rozar Raj B ◽  
Lakshmi Thangavelu

To conduct a study regarding the antibacterial activity of essential oils against bacteria causing Caries. Essential oils are distillates of the volatile compounds of a plant’s secondary metabolism and may act as photoprotective agents. Their curative effect has been known since antiquity. It is based on a variety of pharmacological properties which are specific for each plant species. The mouth contains a variety of oral bacteria, but only a few species of bacteria are believed to cause dental caries. Antibacterial activity of the three essential oils, Rosemary oil, Holy basil oil, Thyme oil was screened against Streptococcus mutans, using disc diffusion technique. The rosemary oil was more effective against Streptococcus mutans with a zone of inhibition of 52 mm diameter (at concentration 200 µl), Rosemary oil showed a zone of inhibition of 44 mm diameter and with thyme oil, the zone diameter was 30 mm. The results of this study showed that the essential oils at different concentrations exhibited antibacterial activity against the bacterial species tested.


2018 ◽  
Vol 7 (4) ◽  
pp. 392-398
Author(s):  
B.T Yunana ◽  
◽  
B. B Bukar ◽  
J. C Aguiyi ◽  
◽  
...  

The ethanol extracts of root, bark and leaf of Bridelia ferruginea was investigated for antibacterial activity against clinical isolate of Staphylococcus aureus and Escherichia coli. The extracts had significant antibacterial activity in vitro at concentration of 25 mg/ml, 50 mg/ml, 100 mg/ml and 200 mg/ml and in vivo at dose of 50 mg/kg and 100 mg/kg. The root extract in vitro had the highest zone of inhibition, followed by the bark extract for both Staphylococcus aureus and Escherichia coli. The concentration of 200 mg/ml had the highest zone of inhibition in vitro. The minimum inhibitory concentration (MIC) showed a decreasing inhibitory effect of the plant extracts for both Staphylococcus aureus and Escherichia coli as the concentration decreases with root having 3.125 mg/ml, bark having 6.25 mg/ml and leaf having 25 mg/ml for Staphylococcus aureus and Escherichia coli. Likewise, the minimum bactericidal concentration (MBC) showed decreasing bactericide effects with decrease concentration with root having 12.5 mg/ml, bark having 12.5 mg/ml and leaf having 25 mg/ml for Escherichia coli while root had 6.25mg/ml, bark had 12.5mg/ml and leaf had 25mg/ml for Staphylococcus aureus. The in vivo investigation showed that the root and bark extract exhibited antibacterial activity on both Staphylococcus aureus and Escherichia coli at doses of 100mg/kg and 50mg/kg; the root extract had higher activity than the bark and root/bark combined. The dose of 100 mg/kg had the highest colonies reduction for Staphylococcus aureus and Escherichia coli in vivo. Preliminary phytochemical screening of root, bark and leaves of Bridelia ferruginea revealed the presence of tannins, flavonoids, carbohydrates, cardiac glycoside (root, bark and leaves), saponins (root and bark). The presence of tannins, saponins, flavonoid, cardiac glycoside and carbohydrate in the bark and root extracts of the plant indicates that the bark and root extracts were pharmacological importance


2021 ◽  
Author(s):  
Smita J. Pawar ◽  
Amol Kale ◽  
Priya Zori ◽  
Rahul Dorugade

Abstract Abstract The new series of 2-(substituted amino)-N-(6- substituted-1,3-benzothiazol-2yl) acetamide BTC(a-t) has been synthesized by appropriate synthetic route from substituted 2-amino benzothiazole. The synthesized compounds were screened experimentally for its antimicrobial property against gram positive, gram negative bacteria and fungi. Zone of inhibition and minimum inhibitory concentration of compounds was determined against selected bacterial and fungal strains. Compound BTC-j N-(6-methoxy-1,3-benzothiazol-2-yl)-2-(pyridine-3-yl amino) acetamide and compound BTC-r N-(6-nitro-1,3-benzothiazol-2-yl)-2-(pyridine-3-yl amino) acetamide found to have good antimicrobial potential. The compound BTC-j has shown good antibacterial activity against S. aureus at MIC of 12.5 µg/ml, B. subtilis at MIC of 6.25µg/ml, E. coli at MIC of 3.125µg/ml and P. aeruginosa at MIC of 6.25µg/ml. No statistical difference in antimicrobial activity of standard and test compounds was found indicating test compounds have comparable activity. Further docking study was carried out to check the probable interactions with the selected protein using V-life MDS 3.5 software. (DNA gyrase, PDB: 3G75). The dock score of compounds and antimicrobial activity found to be consistent.


2021 ◽  
Vol 07 (06) ◽  
Author(s):  
Tulsa Devi ◽  

Antibiotic resistance has become a global concern and hence, the search for other source of antimicrobials initiated to find a way to control infections in future. The main objective of this paper is to screen Giloy (Tinospora cordifolia) for its antibacterial activity. The stem of Tinospora cordifolia is used to prepare extract for determining it’s in vitro antibacterial activity as per the agar well diffusion method. In the agar well diffusion method 100μl of 24 hr broth culture of bacteria was aseptically and evenly swabbed on Mueller Hinton agar plates. Wells of about 8 mm diameter were aseptically cut using sterile cork-borer. 100 μl of plant extracts of different concentrations were then placed into the separate wells. The plates were incubated at 37 oC for 24hr. Antimicrobial activity of the giloy was determined by measuring the diameter of zone of inhibition. The methanolic extract of Tinospora cordifolia showed 13, 11, 9 and 5 mm zone of inhibition in S. aureus cultures by using 100, 75, 50 and 25 mg/ml concentration, respectively while hot water extract of Tinospora cordifolia showed 14, 12, 10 and 8 mm zone of inhibition for S. aureus by using 100, 75, 50 and 25 mg/ml concentration, respectively and the cold extract of Tinospora cordifolia showed 10, 8, 5 and 0 mm zone of inhibition for S. aureus by using 100, 75, 50 and 25mg/ml concentration, respectively. The methanolic extract of Tinospora cordifolia indicated 12, 10, 6 and 4 mm zone of inhibition in cultures of E.coli by using 100, 75, 50 and 25 mg/ml concentration, respectively and the hot water extract of Tinospora cordifolia showed 16, 14, 12 and 10 mm zone of inhibition in cultures of E.coli by using 100, 75, 50 and 25mg/ml concentration, respectively. The cold water extract of Tinospora cordifolia showed 13, 10, 8, and 5 mm zone of inhibition in cultures of E.coli by using 100, 75, 50 and 25 mg/ml concentration, respectively. It has been observed that Tinospora cordifolia showed very promising results as indicated by the zone of inhibition of bacterial culture through agar well diffusion method that varies from few mm to few cm. This study indicates the in-vitro antibacterial effect of Giloy which needs further validation through in-vivo studies.


2021 ◽  
Vol 45 (11-12) ◽  
pp. 1093-1099
Author(s):  
Abdulrhman Alsayari ◽  
Yahya I Asiri ◽  
Abdullatif Bin Muhsinah ◽  
Mohd. Zaheen Hassan

We report the design, synthesis, and in vitro antimicrobial evaluation of functionalized pyrazoles containing a hydrazono/diazenyl moiety. Among these newly synthesized derivatives, 4-[2-(4-chlorophenyl)hydrazono]-5-methyl-2-[2-(naphthalen-2-yloxy)acetyl]-2,4-dihydro-3 H-pyrazol-3-one is a promising antimicrobial agent against Staphylococcus aureus (minimum inhibitory concentration 0.19 μg mL−1). Structure–activity relationship studies reveal that the electronic environment on the distal phenyl ring has a considerable effect on the antimicrobial potential of the hybrid analogues. Molecular docking studies into the active site of S. aureus dihydrofolate reductase also prove the usefulness of hybridizing a pyrazole moiety with azo and hydrazo groups in the design of new antimicrobial agents.


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