scholarly journals Oxo-Titanium(IV) Complex/Polymer Composites—Synthesis, Spectroscopic Characterization and Antimicrobial Activity Test

2020 ◽  
Vol 21 (24) ◽  
pp. 9663
Author(s):  
Piotr Piszczek ◽  
Barbara Kubiak ◽  
Patrycja Golińska ◽  
Aleksandra Radtke

The emergence of a large number of bacterial strains resistant to many drugs or disinfectants currently used contributed to the search of new, more effective antimicrobial agents. In the presented paper, we assessed the microbiocidal activity of tri- and tetranuclear oxo-titanium(IV) complexes (TOCs), which were dispersed in the poly(methyl methacrylate) (PMMA) matrix. The TOCs were synthesized in reaction to Ti(OR)4 (R = iPr, iBu) and HO2CR’ (R’ = 4-PhNH2 and 4-PhOH) in a 4:1 molar ratio at room temperature and in Ar atmosphere. The structure of isolated oxo-complexes was confirmed by IR and Raman spectroscopy and mass spectrometry. The antimicrobial activity of the produced composites (PMMA + TOCs) was estimated against Gram-positive (Staphylococcus aureus ATCC 6538 and S. aureus ATCC 25923) and Gram-negative (Escherichia coli ATCC 8739 and E. coli ATCC 25922) bacteria and yeasts of Candida albicans ATCC 10231. All produced composites showed biocidal activity against the bacteria. Composites containing {Ti4O2} cores and the {Ti3O} core stabilized by the 4-hydroxybenzoic ligand showed also high activity against yeasts. The results of investigations carried out suggest that produced (PMMA + TOCs) composites, due to their microbiocidal activity, could find an application in the elimination of microbial contaminations in various fields of our lives.

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.


2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
M. M. El-ajaily ◽  
H. A. Abdullah ◽  
Ahmed Al-janga ◽  
E. E. Saad ◽  
A. A. Maihub

La(III), Zr(IV), and Ce(IV) chelates of 2-[(4-[(Z)-1-(2-hydroxyphenyl)ethylidene]aminobutyl)-ethanimidoyl]phenol were synthesized and characterized by using several physical techniques. The Schiff base was obtained by refluxing of o-hydroxyacetophenone with 1,4-butanediamine in 2 : 1 molar ratio. The CHN elemental analysis results showed the formation of the Schiff base and the chelates has been found to be in 1 : 1 [M : L] ratio. The molar conductance measurements revealed that all the chelates are nonelectrolytes. Structural elucidations of the ligand and its chelates were based on compatible analytical and spectroscopic evidences. The infrared spectral data revealed that the Schiff base coordinates to the metal ions through active sites which are –OH and –C=N groups. According to the electronic spectral data, an octahedral geometry was proposed for the chelates. The synthesized ligand and its metal chelates were screened for their antimicrobial activity against two Gram negative (Escherichia coli, Salmonella kentucky) and two Gram positive (Lactobacillus fermentum, Streptococcus faecalis) bacterial strains, unicellular fungi (Fusarium solani), and filamentous fungi (Aspergillus niger). The activity data showed that the metal chelates have antibacterial and antifungal activity more than the parent Schiff base ligand against one or more bacterial or fungi species. The results also indicated that the metal chelates are higher sensitive antimicrobial agents as compared to the Schiff base ligand.


F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1200
Author(s):  
Cecilia Barba Guevara ◽  
Luis Montaluisa ◽  
María Elena Maldonado Rodriguez

Background: This research was carried out in order to study the antimicrobial effectiveness of crude latex of two varieties of "Sangre de Drago": Croton lechleri Muller Arg. and Croton urucurana Baill and compare that effectiveness to the antimicrobial activity of the alcoholic extracts of its leaves and bark.  Methods: The activity of the alcoholic extracts and latex were evaluated against bacterial strains of Staphylococcus epidermidis, Bacillus subtilis and Escherichia coli. The extraction of the alcoholic extracts (20% Tincture) of the leaves, bark and latex from the two Croton species was carried out by maceration using 70% alcohol as a menstruum, at room temperature, for 2 to 7 days, with shaking at least twice a day.  A 20% tincture was obtained, from which the physical and chemical parameters were determined as indicated by the Ecuadorian Quality Control Standard for natural medicinal products. Results: It was found that both the alcoholic extracts of the plant material and the crude latex indicate antimicrobial activity for S. epidermidis, moderate antimicrobial activity for B. subtilis and no antimicrobial activity for E. coli. The moderate antimicrobial activity against B. subtilis, at doses of 125 p.p.m., is in line with the findings of previous studies by other authors.  Conclusions: he antimicrobial activity of the latex of the two species against S. epidermidis is not registered in literature and, the negative antimicrobial activity for E. coli does not agree with what has been reported by previous studies.


2018 ◽  
Vol 15 (1) ◽  
pp. 21-30
Author(s):  
Deboleena Dhara ◽  
Dhanya Sunil ◽  
Pooja R. Kamath ◽  
K. Ananda ◽  
S. Shrilakshmi ◽  
...  

Introduction: The escalating threat due to dwindling effect of antibiotics and challenge of tackling rising drug-resistant infections has gathered high focus in current medicinal research. Methods: In an attempt to find new molecules that can defeat microbial resistance, two new series of 2-[2-substituted ethenyl]-5-(substituted methoxy)-1,3,4-oxadiazole derivatives were synthesized. Various aromatic hydrazides were allowed to undergo cyclization to substituted oxadiazole-2- amines in the presence of cyanogen bromide and further condensed with different heterocyclic aldehydes to give new oxadiazole derivatives. The synthesized molecules were fully characterized by various spectral techniques and tested for antimicrobial activity. Results: Almost all the newly synthesized compounds especially (5g-5l) displayed remarkable growth inhibition against three bacterial strains: M. smegmatis, S. aureus, E. coli and fungi C. albicans. The antimicrobial activity was further confirmed by MIC assay against the same microorganisms. Oxadiazole 5g displayed promising activity with a MIC value of 0.025 mM for two bacteria and fungi, whereas MIC of this compound for E. coli was 0.1 mM. Other active compounds (5h-5l) also exhibited good MIC ranging between 0.313 to 5.0 mM against the selected microorganisms. Docking simulations were generated to explore the potential binding approaches of ligand 5g at the D-alanine:d-alanine ligase (Ddl) protein of E. coli and S. aureus. Conclusion: Molecule 5g was active even at a lower concentration and could probably act as a prospective lead molecule for targeting the drug resistant microorganisms.


Author(s):  
Bindhu R. Kamath ◽  
Sabeena Kizhedath

Background: Cassia fistula Linn is a plant which is widely grown in India and is used for medicinal purposes. The study was carried out with an objective to demonstrate the antimicrobial activity of leaves of Cassia fistula Linn. The aim of the study is to assess antibacterial and antifungal activity of methanolic leaf extract of Cassia fistula Linn against selected clinical isolates.Methods: The antimicrobial activity of methanolic extract of Cassia fistula was evaluated using agar well diffusion method and to zone of inhibition of extract was determined. Clinical isolates of Staphyloccocus aureus, MRSA, Pseudomonas aeruginosa, E. coli and Proteus were screened.Results: The methanolic extracts exhibited antibacterial activity against Staphylococcus aureus. The extract was not active against E. coli, Proteus, MRSA, Pseudomonas aeruginosa. The extract also failed to demonstrate antifungal activity against Candida albicans and Aspergillus niger.Conclusions: The global emergence of multidrug resistant bacterial strains is increasing, limiting the effectiveness of current drugs and treatment failure of infections. A novel approach to the prevention of antibiotic resistance of pathogenic species is the use of new compounds that are not based on existing synthetic antimicrobial agents.


INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (07) ◽  
pp. 5-9
Author(s):  
R. G Ingle ◽  
◽  
S. J. Wadher

A set of ten new 2,3-diphenyl-6-sulfonamido quinoxaline derivatives was synthesized and screened for antimicrobial activity by disk diffusion method. Test derivatives R3, R5, R’’1 and R’’2 show promising results against bacterial strains S. aureus gram positive and E. coli gram negative organism with the concentration 1000 μg/mL in disk diffusion method. Rest of the derivatives show sensitivity against the same organisms. All the synthesized derivatives were confirmed by their spectral data.


Author(s):  
TAMANNA SULTANA ◽  
ARUP KUMAR MITRA ◽  
SATADAL DAS

Objectives: Due to emerging drug-resistant microorganisms throughout the world, newer antimicrobial agents should be looked for. Plants are enriched with different bioactive chemicals. In this study, we searched antibacterial activities of some mangrove plant extracts against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. Methods: In the present study, the antimicrobial activity of the leaves of Bruguiera gymnorhiza, Excoecaria agallocha, Avicennia alba, and Aegialitis rotundifolia was evaluated against a few reference pathogenic bacterial strains, namely, P. aeruginosa ATCC 27853, E. coli ATCC 25922, S. aureus ATCC 29213, and multidrug-resistant bacterial strains E. coli extended-spectrum beta-lactamases strain. Aqueous, ethanolic, methanolic, and dimethyl sulfoxide (DMSO) extracts were studied. The antimicrobial activities of the organic solvent extracts on the various test microorganisms were investigated using agar well diffusion technique followed by determination of minimum inhibitory concentration values by serial dilution in a microtiter plate. Results: Ethanol and DMSO extracts of B. gymnorhiza exhibited promising antimicrobial activity followed by extracts of A. alba and E. agallocha. Among all microorganisms studied, P. aeruginosa ATCC 27853 showed significant growth inhibition with ethanol and DMSO extracts. Conclusion: Extracts of some mangrove plants, particularly, B. gymnorhiza showed very good antimicrobial activities against common microbial agents causing human infections and in general mangrove plants appear to act better on P. aeruginosa.


Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7119
Author(s):  
Huda R. M. Rashdan ◽  
Aboubakr H. Abdelmonsef ◽  
Mortaga M. Abou-Krisha ◽  
Tarek A. Yousef

2-azido-1H-benzo[d]imidazole derivatives 1a,b were reacted with a β-ketoester such as acetylacetone in the presence of sodium ethoxide to obtain the desired molecules 2a,b. The latter acted as a key molecule for the synthesis of new carbazone derivatives 4a,b that were submitted to react with 2-oxo-N-phenyl-2-(phenylamino)acetohydrazonoyl chloride to obtain the target thiadiazole derivatives 6a,b. The structures of the newly synthesized compounds were inferred from correct spectral and microanalytical data. Moreover, the newly prepared compounds were subjected to molecular docking studies with DNA gyrase B and exhibited binding energy that extended from −9.8 to −6.4 kcal/mol, which confirmed their excellent potency. The compounds 6a,b were found to be with the minimum binding energy (−9.7 and −9.8 kcal/mol) as compared to the standard drug ciprofloxacin (−7.4 kcal/mol) against the target enzyme DNA gyrase B. In addition, the newly synthesized compounds were also examined and screened for their in vitro antimicrobial activity against pathogenic microorganisms Staphylococcus aureus, E. coli, Pseudomonas aeruginosa, Aspergillus niger, and Candida albicans. Among the newly synthesized molecules, significant antimicrobial activity against all the tested microorganisms was obtained for the compounds 6a,b. The in silico and in vitro findings showed that compounds 6a,b were the most active against bacterial strains, and could serve as potential antimicrobial agents.


2014 ◽  
Vol 2 (4) ◽  
pp. 521-524
Author(s):  
RP Praveen ◽  
Ashalantha Nair

The aim of the present study was to compare the antimicrobial efficacy of methanolic extract of root, callus and fruit of Myxopyrum smilacifolium Blume. Antimicrobial activity was tested using agar well diffusion with four bacterial strains viz: Escherechia coli, Enterococcus faecalis, Bacillus subtilis and Staphylococcus aureus of which E. coli alone was gram negative. The fungal strain employed was Candida albicans. Root extracts shown to be effective only against B. subtilis. Fruit extracts showed the maximum antimicrobial activity against all the microbial species considered for the current study except against S. aureus. Highlight of the present study was the antimicrobial activity of callus extracts. DOI: http://dx.doi.org/10.3126/ijasbt.v2i4.11362  Int J Appl Sci Biotechnol, Vol. 2(4): 521-524 


2014 ◽  
Vol 44 (2) ◽  
pp. 287-290 ◽  
Author(s):  
Carolinie Batista Nobre da Cruz ◽  
Fabio Alessandro Pieri ◽  
Gislene Almeida Carvalho-Zilse ◽  
Patrícia Puccinelli Orlandi ◽  
Carlos Gustavo Nunes-Silva ◽  
...  

Honeys are described possessing different properties including antimicrobial. Many studies have presented this activity of honeys produced by Apis mellifera bees, however studies including activities of stingless bees honeys are scarce. The aim of this study was to compare the antimicrobial activity of honeys collected in the Amazonas State from Melipona compressipes, Melipona seminigra and Apis mellifera against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Chromobacterium violaceum, and Candida albicans. Minimum inhibitory concentrations were determined using the agar dilution method with Müller-Hinton agar (for bacteria) or Saboraud agar (for yeast). Staphylococcus aureus and E. faecalis were inhibited by all honeys at concentrations below 12%, while E. coli and C. violaceum were inhibited by stingless bee honeys at concentrations between 10 and 20%. A. mellifera honey inhibited E. coli at a concentration of 7% and Candida violaceum at 0.7%. C. albicans were inhibited only with honey concentrations between 30 and 40%. All examined honey had antimicrobial activity against the tested pathogens, thus serving as potential antimicrobial agents for several therapeutic approaches.


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