scholarly journals Synthesis, Characterization and Antibacterial Activity Evaluation of New Indole-Based Derivatives

Author(s):  
Ahmed T. Sulaiman ◽  
Susan W. Sarsam

A new series of N-acyl hydrazones (4a-g) derived from indole-3-propionic acid (IPA) were synthesized. These N-acyl hydrazones were prepared by the reaction of 3-(1H-indol-3-yl) propane hydrazide and aldehyde in the existence of glacial acetic acid as a catalyst. 1HNMR and FT-IR analyses were used to identify the synthesized compounds and they were in vitro evaluated as antibacterial agents against six different types of microorganisms by using well diffusion method. All the tested N-acyl hydrazones (4a-g) displayed moderate activity against the Gram-negative E.coli, comparable to that of Amoxicillin. Some of the tested N-acyl hydrazones also exhibited intermediate activity against some of the examined Gram-positive and Gram-negative bacteria. While no activity was exhibited by any of the examined compounds against the Gram-positive S. aureus.

Chemotherapy ◽  
2017 ◽  
Vol 62 (3) ◽  
pp. 194-198 ◽  
Author(s):  
Socorro Leyva-Ramos ◽  
Denisse de Loera ◽  
Jaime Cardoso-Ortiz

Background: Fluoroquinolones are widely prescribed synthetic antimicrobial agents. Quinolones act by converting their targets, gyrase and topoisomerase IV, into toxic enzymes that fragment the bacterial chromosome; the irreversible DNA damage eventually causes the killing of bacteria. Thorough knowledge of the structure-activity relationship of quinolones is essential for the development of new drugs with improved activity against resistant strains. Methods: The compounds were screened for their antibacterial activity against 4 representing strains using the Kirby-Bauer disk diffusion method. Minimal inhibitory concentration (MIC) was determined by measuring the diameter of the inhibition zone using concentrations between 250 and 0.004 μg/mL. Results: MIC of derivatives 2, 3, and 4 showed potent antimicrobial activity against gram-positive and gram-negative bacteria. The effective concentrations were 0.860 μg/mL or lower. MIC for compounds 5-11 were between 120 and 515 μg/mL against Escherichia coli and Staphylococcus aureus, and substituted hydrazinoquinolones 7-10 showed poor antibacterial activity against gram-positive and gram-negative bacteria compared with other quinolones. Conclusion: Compounds obtained by modifications on C-7 of norfloxacin with the acetylated piperazinyl, halogen atoms, and substituted hydrazinyl showed good in vitro activity - some even better than the original compound.


2019 ◽  
Vol 4 (2) ◽  
pp. 61-65
Author(s):  
Surahmaida . ◽  
Kinanti Ayu Puji Lestari

ABSTRAKPenelitian ini bertujuan untuk mengetahui kemampuan Kombucha dalam menghambat pertumbuhan bakteri Gram positif dan Gram negatif. Metode yang digunakan dalam penelitian ini meliputi pembuatan Kombucha dengan variasi bahan dasar (teh hitam, teh hijau dan kopi) dengan jenis gula yang berbeda (gula pasir dan gula stevia); dan uji antibakteri menggunakan metode kertas cakram (difusi agar) terhadap bakteri Gram positif dan Gram negatif. Hasil penelitian menunjukkan ke-6 varian Kombucha tidak berpengaruh atau tidak adanya zona bening (zona hambat) yang terbentuk di sekitar kertas cakram uji pada semua bakteri uji.Kata kunci: Kombucha teh dan kopi, bakteri Gram positif dan bakteri Gram negatif, zona hambat ABSTRACTThe aim of this tudy is to determine the ability of Kombucha to inhibit the growth of Gram positive and Gram negative bacteria. The method used in this study included the making of Kombucha with a variety of basic ingredients (black tea, green tea and coffee) with different types of sugar (sugar and stevia sugar); and antibacterial tests using the paper disc (agar diffusion) method against Gram positive and Gram negative bacteria. The results showed that the 6 variants of Kombucha had no effect or absence of a clear zone (inhibition zone) formed around the test disc paper in all test bacteria.Keywords: Tea and coffee Kombucha, Gram positive bacteria and Gram negative bacteria, inhibitory zone


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.  


2007 ◽  
Vol 53 (1) ◽  
pp. 75-81 ◽  
Author(s):  
M Shahid ◽  
Anwar Shahzad ◽  
Abida Malik ◽  
M Anis

Leaves, stem, and flowers of Saraca asoca, an endangered medicinal plant in India, and young explants cultivated on Murashige & Skoog's medium containing 6-benzylaminopurine were analyzed for antibacterial potential. Alcoholic and aqueous extracts from parent explants and their in vitro raised calli were tested by an agar well diffusion method. Minimal inhibitory concentrations (MICs) of the extracts were determined by broth microdilution method. Aqueous extracts showed antibacterial activity against limited bacterial species, whereas alcoholic extracts were active against a wider range of bacteria. Although the alcoholic extracts of all the explants and calli showed antibacterial activity, the extracts derived from flowers and their calli showed better results. Extracts derived from calli showed comparable results to the extracts from explants. Overall, the MICs of the extracts ranged from 0.039 to 1.25 mg/mL. MICs against Gram-positive bacteria ranged from 0.078 to 1.25 mg/mL, whereas they ranged between 0.039 and 0.625 mg/mL against Gram-negative bacteria. A MIC distribution plot showed that Gram-negative bacteria were more susceptible to the extracts than Gram-positive bacteria. It is concluded that extracts of S. asoca contain antibacterial agent, and as the calli gave good results, in vitro cultivation of the explants may be used to obtain antibacterial compounds. This is the first report on antibacterial activity of S. asoca, especially through in vitro raised calli.Key words: Saraca asoca, antibacterial activity, in vitro, callus, minimal inhibitory concentration.


2013 ◽  
Vol 7 (2) ◽  
pp. 17-23
Author(s):  
Dalia Abd Al Kader Al-Salih ◽  
Fitua M. Aziz ◽  
Bahir Abdul Razzaq Mshimesh ◽  
Muhanad T. Jehad

Overuse of antibiotics has become the major factor for the emergence and dissemination of multi-drug resistant strains of several groups of microorganisms and this lead to search for agents that may have antibacterial effects. Vitamin E emerged as an essential, fat-soluble nutrient in the human body and it is essential, because the body cannot manufacture its own vitamin E, so foods and supplements must provide it. The aim of the present study was to evaluate the effect of vitamin E against pathogenic bacteria. Gram positive and gram negative bacteria were selected as the test microorganisms based on their importance in infections. In this study vitamin E used in four concentrations (50,100,200,400) IU/ml. The agar diffusion method was used to determine antibacterial activity. Results showed that gram negative bacteria were shown to be more resistant than gram positive bacteria. The resistance of gram negative bacteria towards antibacterial substances may be related to lipopolysaccharides in their outer membrane.


2021 ◽  
Vol 29 (2) ◽  
pp. 183-190
Author(s):  
I.V. Shipitsyna ◽  
◽  
E.V. Osipova ◽  
A.A. Natalskiy ◽  
A.V. Pavlov ◽  
...  

Objective. To determine the species composition of the associations isolated from osteomyelitis foci and to study the character of associate relationships based on the biofilm-forming ability data. Methods. The microbiological study included clinical isolates (n=184) obtained from associations (n=88) during primary inoculations from wounds and fistulas of patients (n= 88) with chronic osteomyelitis of long tubular bones. In order to obtain an associative biofilm in vitro, the cultures of competing bacterial strains were daily mixed in 1:1 ratio. The biofilms were grown on the surface of polystyrene plates with subsequent determination of the level of biofilm formation in 24 and 48 hours. Thecoefficient of relationship (CR) was calculated to evaluate the synergistic, neutral and antagonistic relationships between bacteria in the biofilms. Results. The associations of staphylococcus with gram-negative bacteria were most frequently recovered from osteomyelitis foci. On the 1st day of the experiment, 38,6 % of associations had a moderate biofilm-forming ability, and besides, associations of gram-positive + gram-negative bacteria were observed in 36,4%; 42,1% of associations had a low biofilm-forming ability; 19,3% - had a high biofilm-forming ability. After 48 hours the percentage of mild adhesive strains remained at the same level - 38,6%, as for the low adhesive ones it decreased to 36,4%, high adhesive - increased up to 25%. Most bacterial associations manifested antagonistic relationships. Synergism in biofilm-formingby the association of S. aureus + P. aeruginosa was observed in 2 cases,while the level of film-forming was high as on the first and the second day of the study. In several associations it transformed from antagonistic to synergistic or neutral relationships. Conclusion. It has ben established that among the identified associations, the largest specific weight falls on the associations of gram-positive + gram-negative bacteria , while S. aureus is one of the most common components. These associations were noted to have high and mild activity of biofilm -forming on the surface of polystyrene plates. Relationships between the microorganisms isolated from osteomyelitis foci in associations, as a rule, are antagonistic. What this paper adds For the first time, the nature of the relationship between microorganisms in the composition of associations isolated from the osteomyelitis focus has been studied on the basis of biofilm-forming ability data. It has been established that in microbiocenosis of the osteomyelitis foci, the greatest specific weight falls on the associations of S. aureus with gram-negative bacteria. These associations have a high and moderate activity of biofilm formation on the surface of polystyrene plates. The relationships between microorganisms isolated from the osteomyelitis focus as part of associations are usually antagonistic.


2019 ◽  
Vol 10 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Maysoon Mohammed Almahdi ◽  
Ahmed Elsadig Mohammed Saeed ◽  
Nadia Hanafy Metwally

In the present study, a series of new pyrazoline derivatives bearing sulfanilamido moiety were synthesized and obtained in good yields. The chemical structures of the compounds were elucidated by spectral data (FT-IR, MS, UV-VIS and NMR). The synthesized compounds 41-70 were screened for their antimicrobial activity and compared with controls. The in vitro antibacterial activity of compounds 41-45 and 48-57 was checked against two Gram positive microorganisms (S. aureus and S. mutans) and three Gram negative microorganisms (E. coli, K. pneumonia and P. aureginosa), their antifungal activity was checked against C. albicans. The preliminary results showed that these compounds had moderate activity against the tested organisms. Compounds 41, 48, 51 and 56 exhibited promising antimicrobial activity against S. aureus compared to standard drug Ampicilin. Final synthesized compounds 58-70 were tested against two Gram positive (S. aureus and B. subtilis) and two Gram negative (E. coli and P. aureginosa) microorganisms, their activity against C. albicans was also checked and they did not exhibit any antimicrobial activity.


Author(s):  
Sushma Vashisht ◽  
Manish Pal Singh ◽  
Viney Chawla

The methanolic extract of the resin of Shorea robusta was subjected to investigate its antioxidant and antibacterial properties its utility in free radical mediated diseases including diabetic, cardiovascular, cancer etc. The methanol extract of the resin was tested for antioxidant activity using scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazil) radical method, reducing power by FeCl3 and antibacterial activity against gram positive and gram negative bacteria using disc diffusion method. The phytochemical screening considered the presence of triterpenoids, tannins and flavoniods. Overall, the plant extract is a source of natural antioxidants which might be helpful in preventing the progress of various oxidative stress mediated diseases including aging. The half inhibition concentration (IC50) of resin extract of Shorea robusta and ascorbic acid were 35.60 µg/ml and 31.91 µg/ml respectively. The resin extract exhibit a significant dose dependent inhibition of DPPH activity. Antibacterial activity was observed against gram positive and gram negative bacteria in dose dependent manner.Key Words: Shorea robusta, antioxidant, antibacterial, Disc-diffusion, DPPH.


Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.


2012 ◽  
Vol 28 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Md Atiar Rahman ◽  
Rumana Sharmin ◽  
Md Nazim Uddin ◽  
Md Sohel Rana ◽  
Nazim Uddin Ahmed

Antibacterial effect of Crinum asiaticum bulb extract (1mg/disc) was tested on four Gram- positive and six Gram-negative bacteria by disc diffusion method using kanamycin (30 ìg/disc) as standard antibiotic disc. The bulb extract (250-1000mg/disc) showed significant zone of inhibition against all Gram-positive and Gram-negative bacteria ranging from 12-14 mm in diameter. Antioxidant potential of the same extract was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. The extract showed remarkable free radical scavenging effect (95.96%) providing the IC50 value of 5.62 for the bulb extract and 5.46 for ascorbic acid (standard antioxidant) at the concentration of 1000 ìg/ml. The bulb extract was found to be (LC50 value 94.06 ?g/ml) in Brine-Shrimp lethality test. DOI: http://dx.doi.org/10.3329/bjm.v28i1.11801 Bangladesh J Microbiol, Volume 28, Number 1, June 2011, pp 1-5


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