scholarly journals Synthesis and Study of Some Newer Analogues ofQuinolin-8-ol as Potent Antimicrobial Agents

2008 ◽  
Vol 5 (s1) ◽  
pp. S1008-S1014
Author(s):  
Jyoti Sharma ◽  
Sabir Hussain ◽  
Mohammad Amir

New series of 4-(substituted phenyl)-5-[(quinolin-8-yloxy) methyl]-4H-1,2,4-triazole-3-thiol(4a-c),N³-(4-substituted phenyl)-5-[(quinolin-8-yloxy) methyl]-4H-1,2,4-triazole-3,4-diamine(5a-c)andN-(4-substituted phenyl)-5-[(quinolin-8-yloxy) methyl]-1,3,4-thiadiazol-2-amine(6a-g)have been synthesized and the structures of the new compounds were established on the basis of IR,1H NMR spectral data.In vitroantimicrobial activity (MIC activity) was evaluated and compared with standard drugs of loxacin and ketoconazole. Compounds5aand6ein the series have shown interesting antibacterial activity against bothS. aureus(gram-positive) andE. coli(gram-negative) organisms. In this paper, we also describe studies leading to identification of antifungal agents. In the gratifying result, most of the compounds were found to have moderate antimicrobial activity.

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.


2021 ◽  
Vol 33 (7) ◽  
pp. 1525-1529
Author(s):  
Parmesh Kumar Dwivedi ◽  
Devdutt Chaturvedi

A new series of fluorinated sulfur inserted benzimidazole analogues Za-i were synthesized and characterized. The new compounds were screened for their antimicrobial and antioxidant potential. The synthesized compounds were obtained by multiple step synthesis, initiating from the synthesis of 5-(difluoromethoxy)-1H-benzimidazole-2-thiol X. The compounds Ya-i prepared by reacting differently substituted anilines with chloroacetylchloride and triethylamine in DMF. Finally, the compound X was reacted with different derivatives of 2-chloro-N-phenylacetamide resulting in formation of titled compounds Za-i. The synthesized compounds (Za-Zi) were characterized by spectral analysis viz.1H & 13C NMR, mass spectra, elemental analysis and IR. The in vitro antimicrobial potential against Gram-positive (S. aureus and E. faecalis) and Gram-negative bacterial (E. coli and P.aeruginosa) strains as well as fungi (A. niger and C. albicans) was recorded for the obtained compounds. Some of the compounds exhibited encouraging results (in MIC) against Gram-positive and Gram-negative bacterial strains. These studies thus suggest that the designed sulfur inserted fluoro-benzimidazoles scaffold may serve as new promising template for further amplification as antimicrobial agents.


Author(s):  
Jyotindra Mahyavanshi ◽  
Maharshi Shukla ◽  
Kokila Parmar

<p class="Default">A new series of<em> </em><em><span>N-</span></em><span>[4-(3-Oxo-3-phenyl-propenyl)-phenyl]-2-(4-phenyl-5-pyridine-4yl-<em>4H</em>-[1,2,4]triazole-3-ylsulfanyl)-acetamide</span> have been synthesized by the claisen-schimodt condensation of <em>N</em>-(4-Acetyl-phenyl)-2-(4-phenyl-5-pyridin-4-yl-4<em>H-</em>[1,2,4]triazole-3-ylsulfanyl) and various aldehyde. The novel compounds structure has been established on the basis of their substituted aldehyde derivatives. All the compounds were characterized by FT-IR, Mass, and <sup>1</sup>H-NMR spectroscopy. These new compounds were evaluated for their in vitro antibacterial activity and anti-fungal activity.</p>


2015 ◽  
Vol 80 (6) ◽  
pp. 739-747 ◽  
Author(s):  
Hemali Lad ◽  
Rakesh Giri ◽  
Yogita Chovatiya ◽  
Dinkar Brahmbhatt

In search for new antimicrobial agents a series of new modified pyridine and bipyridine substituted coumarins 5a-y was designed and synthesized by adopting molecular hybridization strategy. All the synthesized compounds were evaluated for their in vitro antimicrobial activity using broth dilution method against selected bacterial (Gram-positive and Gram-negative) and fungal strains. Compounds 5a, 5f, 5g, 5n, 5r, 5t, 5w, 5x and 5y demonstrated promising antibacterial activity while other derivatives showed comparable activity to standard drugs used as reference.


2020 ◽  
Vol 32 (10) ◽  
pp. 2601-2605
Author(s):  
K.R. Raghavendra ◽  
P. Sudeep ◽  
K. Ajay Kumar ◽  
H.P. Jayadevappa

A series of novel thiophene conjugated benzothiazepines were synthesized by the reaction of chalcones with 2-aminobenzenethiol in citrus juice medium. The new compounds were characterized by spectroscopic studies. Results of in vitro antimicrobial evaluation of newly synthesized compounds 5a-j shows that the compounds 5a and 5c have excellent antimicrobial inhibition in the range of 12.5-25.0 μg/mL against bacteria S. aureus, E. coli, P. aeruginosa and fungi A. niger, A. flavus organisms comparable to ciprofloxacin and nystatin and therefore these compounds might acts as lead molecules as antimicrobial agents.


2012 ◽  
Vol 9 (4) ◽  
pp. 2493-2500
Author(s):  
Sayali D. Kudale ◽  
Meenakshi N. Deodhar

A series of the Schiff’s bases incorporating coumarin and chalcone moeities, 3-(4-(4-(substituted phenyl)prop-1-ene-3-one) phenylimino) methyl)-4-chloro-2h-chromen-2-one 4(a-g) were synthesized as potential antimicrobial agents. These compounds were characterized on the basis of their spectral (IR,1H NMR) data and evaluated for antimicrobial activity in vitro against gram positive and gram negative bacteria and fungi. Compound 4b was found to be most active with an MIC of 20 µg/mL against all the tested organisms.


2012 ◽  
Vol 9 (4) ◽  
pp. 2079-2088 ◽  
Author(s):  
Vishakha Bansode ◽  
Meenakshi N. Deodhar

A series of the title compounds 3-(4-(4, 5-dihydro-5-(substituted phenyl)-1H-3-pyrazolyl) phenylimino) methyl)-4-chloro-2H-chromen-2-one 5(a-g) have been synthesized. These compounds were characterized on the basis of their spectral (IR,1H NMR) data and evaluated for antimicrobial activityin vitroagainst gram positive bacteria, gram negative bacteria and fungi. The compound (5b) was found to be the most active with MIC of 20 µg/ml against all the tested organisms.


2009 ◽  
Vol 6 (3) ◽  
pp. 759-762 ◽  
Author(s):  
Shriram Bairagi ◽  
Ashok Bhosale ◽  
Meenakshi N. Deodhar

4-Chloro-2-oxo-2H-chromene-3-carbaldehyde(2)was reacted with different anilines in rectified spirit as solvent to yield a series of the title compoundsi.e. 4-chloro-3-((substituted-phenylimino) methyl)-2H-chromen-2-one(3a-i). These compounds were charaterised on the basis of their spectral (IR,1H NMR) data and evaluated for antimicrobial activityin vitroagainst gram positive and gram negative bacteria and fungi. Compound3Cwas found to be most active with an MIC of 15 μg /mL against all the tested organisms.


Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.


Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4383
Author(s):  
Barbara Lapinska ◽  
Aleksandra Szram ◽  
Beata Zarzycka ◽  
Janina Grzegorczyk ◽  
Louis Hardan ◽  
...  

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S.mutans and L.acidophilus, as well as antifungal effect on C.albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S.mutans and L.acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S.mutans. All tested EOs exhibited antifungal activity against C.albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S.mutans and C.albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L.acidophilus.


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