scholarly journals Synthesis and Evaluation of Some Coumarin Based Schiff's Bases as Potential Antimicrobial Agents'

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.

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.


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):  
Halah A. Sahib ◽  
Mohammed H. Mohammed

A A new series of bases of Schiff (H2-H4) derived from phthalic anhydrideweresynthesized. These Schiff bases were prepared by the reaction of different amines (tyrosine methyl ester, phenylalanine methyl ester, and isoniazid) with the phthalimide derived aldehyde with the aid of glacial acetic acid or triethylamine ascatalysts. All the synthesized compounds were characterized by (FT-IR and 1HNMR) analyses and were in vitro evaluated for their antimicrobial activity against six various kinds of microorganisms. All the synthesized compounds had been screened for their antimicrobial activity against two Gram-positive bacteria “Staph. Aureus, and Bacillus subtilis”, two Gram-negative bacteria “Escherichia coli, and Klebsiella pneumoniae”, and two fungi species “Candida tropicalis and Candida albicans” using concentrations of 62.5, 125 and 250 µg\mLof derivative in dimethyl sulfoxide(DMSO). All the synthesized compounds showed no activity at all against Gram-positive bacteria, for Gram-negative bacteria and fungi they showed moderate or no activity except compound H1revealedhigh antifungal activityagainstCandida tropicalisat concentrations 125 and 250 µg\ mL. Keywords: Schiff base, phthalic anhydride, antimicrobial.  


Author(s):  
Shipra Baluja ◽  
Sumitra Chanda ◽  
Paras Ramavat

A series of oxadiazole derivatives were synthesized and were characterized by IR, 1H NMR and mass spectroscopy. All these synthesized compounds were tested for in vitro antimicrobial against four Gram positive bacteria, four Gram negative bacteria and four fungal strains in DMSO and DMF.


2017 ◽  
Vol 82 (5) ◽  
pp. 495-508 ◽  
Author(s):  
Aleksandra Bozic ◽  
Nenad Filipovic ◽  
Irena Novakovic ◽  
Snezana Bjelogrlic ◽  
Jasmina Nikolic ◽  
...  

Fourteen mono- and bis-carbohydrazone ligands have been synthesized and characterized. Antioxidant activity of the substances was investigated together with possible (E)/(Z) isomerization, and explained on the most active antioxidant compound 4 in various dimethyl sulphoxide?water mixtures. The addition of water to the system was involved in the formation of hydrated molecules which was confirmed in NMR after the addition of D2O. The ligands were tested in vitro against Gram-positive and Gram-negative bacteria and fungi, and their activity was discussed in relation to the structure of investigated carbohydrazone.


2009 ◽  
Vol 59 (2) ◽  
pp. 145-158 ◽  
Author(s):  
Mosaad Mohamed ◽  
Ramdan El-Domany ◽  
Rania Abd El-Hameed

Synthesis of certain pyrrole derivatives as antimicro-bial agentsIn an effort to establish new pyrroles and pyrrolo[2,3-d] pyrimidines with improved antimicrobial activity we report here the synthesis andin vitromicrobiological evaluation of a series of pyrrole derivatives. A series of new 2-aminopyrrole-3-carbonitriles (1a-d) were synthesized from the reaction of benzoin, primary aromatic amines and malononitrile, from which a number of pyrrole derivatives (2a-dto5a-d) and pyrrolo[2,3-d]pyrimidines (6a-dto10a, d) were synthesized. Thein vitroantimicrobial testing of the synthesized compounds was carried out against Gram-positive, Gram-negative bacteria and fungi. Some of the prepared compounds, [2-amino-1-(2-methylphenyl)-4,5-diphenyl-1H-pyrrole-3-carbonitriles (1b), 2-amino-3-carbamoyl-1-(3-methylphenyl)-4,5-diphenyl-1H-pyrroles (2b),N-(3-cyano-1-(2-methylphenyl)-4,5-diphenyl-1H-pyrrol-2-yl)-acetamides (3b),N-(3-cyano-1-(3-methylphenyl)-4,5-diphenyl-1H-pyrrol-2-yl)-acetamides (3c), 2-amino-1-(4-methoxyphenyl)-4,5-diphenyl-3-tetrazolo-1H-pyrroles (5d),7-(4-methoxyphenyl)-5,6-diphenyl-7H-pyrrolo [2,3-d]pyrimidin-4(3H)-ones (7d), 7-(3-methylphenyl)-5,6-diphenyl-7H-pyrrolo[2,3-d]pyrimidin-4(3H)-thione (9b) andN-(7-(2-methylphenyl)-5,6-diphenyl-7H-pyrrolo[2,3-d] pyrimidine)-N-aryl amines (10a)] showed potent antimicrobial activity.


2009 ◽  
Vol 6 (s1) ◽  
pp. S342-S346 ◽  
Author(s):  
Y. S. Chhonker ◽  
B. Veenu ◽  
S. R. Hasim ◽  
Niranjan Kaushik ◽  
Devendra Kumar ◽  
...  

Some new 2- phenyl benzimidazole derivatives were synthesised by cyclocondensation with appropriate reagents. The compounds synthesised were identified by1H NMR, FAB Mass and FT-IR spectroscopic techniques. All compounds studied in this work were screened for theirin vitroantimicrobial activities against the standard strains:Staphylococcus aureusATCC - 25923, ATCC - 441 andBacillus subtilisATCC- 6633 as gram positive,Escherichia coliATCC - 11775 andPseudomonas aeruginosaATCC 10145 as gram negative bacteria. Some of the compounds inhibited the growth of gram-positive bacteria (B. subtilisandS. aureus) at MIC values between 25 and 200 mg/mL. Some of the compounds exhibit antimicrobial activity against gram negative bacteria (E. coliandP. Aeruginosa) MIC values between 25 and 200 mg/mL.


2012 ◽  
Vol 7 (7) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Rajesh K. Joshi ◽  
Vijaylaxmi Badakar

The essential oil of the flowers of Tridax procumbens L. was obtained by hydro-distillation and analyzed by gas chromatography equipped with a flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). Twenty-six compounds were identified, which comprised 90.6% of the total constituents. The most abundant compound was ( Z)-falcarinol (25.9%), followed by α-selinene (15.3%), limonene (8.3%) and zerumbone (4.3%). Antimicrobial activity was tested against six Gram-positive and eight Gram-negative bacteria, and three fungi. The oil was active against the tested Gram-positive bacteria at a concentration range of 0.14 ± 0.03 - 0.57±0.05 mg/mL, while 0.67 ± 0.12 - 4.58 ± 0.41 mg/mL was effective against the studied Gram-negative bacteria. Remarkable antifungal activity was found against the tested fungi at a concentration range of 0.06 ± 0.008 - 0.10 ± 0.01 mg/mL.


Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 451
Author(s):  
Jung-Kil Seo ◽  
Dong-Gyun Kim ◽  
Ji-Eun Lee ◽  
Kwon-Sam Park ◽  
In-Ah Lee ◽  
...  

American oyster defensin (AOD) was previously purified from acidified gill extract of the American oyster, Crassostrea virginica. AOD is composed of 38 amino acids with three disulfide bonds and exhibits strong antimicrobial activity against Gram-positive bacteria as well as significant activity against Gram-negative bacteria. Here, to develop promising peptides into antibiotic candidates, we designed five arginine-rich analogs (A0, A1, A2, A3, and A4), predicted their loop and extended strand/random structures—including nine amino acids and a disulfide bond derived from the C-terminus of AOD—and described their antimicrobial and cytotoxic effects, as well as their modes of action. In our experimental results, the A3 and A4 analogs exhibited potent antimicrobial activity against all test organisms—including four Gram-positive bacteria, six Gram-negative bacteria, and Candida albicans—without cell toxicity. A sequence of experiments, including a membrane permeabilization assay, DNA binding study, and DNA polymerization inhibition test, indicated that the two analogs (A3 and A4) possibly did not act directly on the bacterial membrane but instead interacted with intracellular components such as DNA or DNA amplification reactions. AOD analogs also showed strong bacterial inhibition activity in the plasma environment. In addition, analog-treated microbial cells clearly exhibited membrane disruption, damage, and leakage of cytoplasmic contents. Collectively, our results suggest that two analogs, A3 and A4, have potent antimicrobial activity via DNA interaction and have the potential for development into novel antimicrobial agents.


Sign in / Sign up

Export Citation Format

Share Document