scholarly journals Fine-tuning of the hydrophobicity of caffeic acid: studies on the antimicrobial activity against Staphylococcus aureus and Escherichia coli

RSC Advances ◽  
2015 ◽  
Vol 5 (66) ◽  
pp. 53915-53925 ◽  
Author(s):  
Mafalda Andrade ◽  
Sofia Benfeito ◽  
Pedro Soares ◽  
Diogo Magalhães e Silva ◽  
Joana Loureiro ◽  
...  

Caffeic acid derivatives are proposed to act as cell permeabilizers, inducing membrane alterations, causing rupture with potassium leakage, particularly on the Gram positive bacterium, and consequent cell death.

2018 ◽  
Vol 13 (2) ◽  
pp. 1934578X1801300 ◽  
Author(s):  
Ninh The Son ◽  
Masataka Oda ◽  
Naoki Hayashi ◽  
Daiki Yamaguchi ◽  
Yu Kawagishi ◽  
...  

The vulnerable plant Dalbergia tonkinensis Prain, is a rare species, native to Vietnam. Phytochemical investigations and biological evaluations of this species are quite limited. Antimicrobial screening has suggested that, at the low dose of 1.0 mg/mL, the methanol extracts of the leaf, stem bark, and root, as well as chloroform fraction of heartwood can serve as useful sources against seven gram-positive skin microbacteria, Bacillus cereus (ATCC27522), Escherichia coli (JM109), Staphylococcus aureus (ATCC25923), Staphylococcus epidermidis (ATCC14990), Streptococcus pneumonia (ATCC49619), Streptococcus pyogenes (ATCC12344), and Vibrio parahaemolyticus (RIMD2210010), and four oral gram-positive microbacteria Streptococcus mutans (ATCC 25175), Streptococcus mitis (ATCC903), Streptococcus sobrinus (ATCC 33478), and Porphyromonas gingivalis (ATCC33277), with an inhibitory percentage of 60-80% growth for several strains Bacillus cereus, Escherichia coli, and Streptococcus pneumonia. We further assessed antimicrobial activities of the enriched diverse flavonoids from chloroform fraction of its heartwood. Extensive structural activity relationship studies showed structure function closely related to the antimicrobial activity, in which methoxylation at C-2’, and 4’ in isoflavanones, hydroxylation at C-3’ in flavones, substitution at C-5 in isoflavones, and lactone opened ring in neoflavonoids were found to increase the effective inhibitions. In the second antimicrobial assessment, the isolated flavonoid liquiritigenin showed the MIC values of 50, and 100 μg/mL against the microbacterial strains Staphylococcus aureus subsp. aureus (ATCC 11632), and Aspergillus niger (439), respectively, whereas the MIC value of 100 μg/mL was assignable to biochanin A against microbacterium Staphylococcus aureus subsp. aureus.


Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2047 ◽  
Author(s):  
Izabela Przybyłek ◽  
Tomasz M. Karpiński

Researchers are continuing to discover all the properties of propolis due to its complex composition and associated broad spectrum of activities. This review aims to characterize the latest scientific reports in the field of antibacterial activity of this substance. The results of studies on the influence of propolis on more than 600 bacterial strains were analyzed. The greater activity of propolis against Gram-positive bacteria than Gram-negative was confirmed. Moreover, the antimicrobial activity of propolis from different regions of the world was compared. As a result, high activity of propolis from the Middle East was found in relation to both, Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) strains. Simultaneously, the lowest activity was demonstrated for propolis samples from Germany, Ireland and Korea.


2021 ◽  
Vol 11 (1) ◽  
pp. 108-109
Author(s):  
Kinjal H Shah ◽  
Piyush M. Patel

Evaluation of antimicrobial activity was performed by cup-plate method. The test microorganisms used for the antimicrobial activity were four bacterial species (two Gram positive and two Gram negative) – Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeuroginosa,Escherichia coli. The test microorganisms used for the antimicrobial activity were four bacterial species (two Gram +ve and two Gram -ve) Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeuroginosa,Escherichia coli.  


2021 ◽  
Author(s):  
◽  
Hadeel Alhazmi

This thesis describes phytochemical studies on the methanolic extract of Curcuma longa; a medicinally important plant used as indigenous medicine for the treatment of wounds in South Asian and African countries. The crude extract displayed antibacterial activity against the Gram-positive bacterium, Staphylococcus aureus, but was inactive against Gram-positive bacterium Streptococcus agalactiae. This extract also did not show antibacterial activity against Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa. Based on the observed antibacterial activity, it was decided to carry out phytochemical investigation of crude methanolic extract of C. longa to isolate and characterize natural products and evaluate them for antimicrobial activity. These efforts resulted in the identification of three known natural products: curcumin (39) sclareolide (40) and atalantoflavone (41). Structures of these compounds were established with the aid of NMR spectroscopic studies. Compounds (40) and (41) have been isolated for the first time from this plant. Compounds (39-41) were found to be inactive against the Gram-positive bacterium, Staphylococcus aureus, and Gram-negative bacterium, Escherichia coli.


2018 ◽  
Vol 69 (3) ◽  
pp. 720-724 ◽  
Author(s):  
Olimpia Dumitriu Buzia ◽  
Valeria Fasie ◽  
Nela Mardare ◽  
Camelia Diaconu ◽  
Gabriela Gurau ◽  
...  

This paper aimed at the preparation and characterisation of an extractive solution of Kombucha. We have applied the method of water extraction of a species of yeast, Kombucha, grown and proliferated in the pharmaceutical technology laboratory of the Faculty of Pharmacy at Dunarea de Jos University of Galati. Samples of various sugar concentrations have been prepared, as well as samples subject to concentration, thus obtaining extracts of up to 80% concentration. The extract obtained was analysed chemically and microbiologically. The main elements highlighted in the composition of the extractive solution were: iron, zinc, magnesium, calcium and potassium. The antimicrobial activity in strains: Gram-positive: Staphylococcus aureus, Gram-negative: Pseudomonas aeruginosa, Escherichia Coli, fungi: Candida albicans.


Author(s):  
Gani Sharmila Banu ◽  
Ganesan Kumar ◽  
Palaniappan Umamagesh ◽  
Subramanian Karthikeyan

The saponin extract of Trianthema portulacastrum were screened for anti-bacterial activity against three pathogenic microbes; Escherichia coli, Staphylococcus aureus and Candida albicans. The extract inhibited the growth of the S. aureus. It was concluded that the saponins have inhibitory effect on gram-positive organism but not on gram negative organism and the fungi.


2016 ◽  
Vol 1 (01) ◽  
Author(s):  
Vemavarapu Bhaskara Rao ◽  
Kandlagunta Guru Prasad ◽  
Krishna Naragani ◽  
Vijayalakshmi Muvva

The air dried rhizosphere soil samples pretreated with calcium carbonate was employed for the isolation of actinomycete strains. Serial dilution plate technique was used for the isolation of actinomycetes. A total of 20 actinomycete strains designated as BS1-BS20 were isolated from the rhizosphere of medicinal plant Clitoria ternatea. All the 20 strains were subjected to primary screening for antimicrobial activity. Among the 20 strains screened, 10 strains exhibited high antimicrobial spectrum against Staphylococcus aureus, Escherichia coli and Candida albicans.


2019 ◽  
Author(s):  
Chem Int

Novel acyclic and cyclic merocyanine dyes derived from the nucleu of furo [(3,2-d) pyrazole; ( d 2 , 3 )imidazole]were prepared. The electronic visible absorptionspectra of all the synthesized new cyanine dyes were examined in 95% ethanolsolution to evaluate their photosensitization properties. Antibacterial andantifungal activities for some selected dyes were tested against various bacterialand fungal strains (Escherichia coli, Staphylococcus aureus, Aspergillus flavus andCandida albicans) to evaluate their antimicrobial activity. Structural identificationwas carried out via elemental analysis, visible spectra, IR and 1H NMRspectroscopic data.


2019 ◽  
Vol 18 (5) ◽  
pp. 262-274
Author(s):  
E. Benyagoub ◽  
N. Nabbou ◽  
S. Boukhalkhel ◽  
I. Dehini

The medicinal value of the plants is due to their chemical components that bring a definite physiological action on the human body to prevent the diseases. In this work, we investigated the antimicrobial activity of leaves’ extracts of Quercus robur L., collected from the Algerian upper highlands, on ten bacterial strains and one fungal strain known to be pathogenic. First, we performed a qualitative phytochemical analysis, and second, antimicrobial activity tests performed by agar diffusion method (disc and well) with the determination of MIC by broth macro-dilution method. Given the results, it appears that obtained macerates of Quercus robur L. were rich in bioactive phytoconstituents such as alkaloids, anthraquinones, saponins, tannins, and other components. The yield of aqueous and methanolic macerates of leaves was 8.5 ± 1.41 and 22.4 ± 4.36%, respectively. The bacterial resistance was relatively important to several antibiotics, namely, ampicillin, amoxicillin + clavulanic acid for strains of Escherichia coli and Salmonella sp. However, Staphylococcus aureus strains were resistant to fusidic acid, penicillin, and oxacillin; while Enterococcus faecalis was resistant to fusidic acid, penicillin, oxacillin, and ticarcillin. The antibacterial activity of the macerates toward tested microbial strains showed that the aqueous and methanolic macerates of the leaves were proportional to the tested concentration and active not only against Gram-positive and Gram-negative bacteria but also on the fungal species Candida albicans. The estimated MIC for Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus was in the order of 10 mg/mL, which seems more effective than toward Salmonella sp., Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans which were in the order of 30 mg/mL. These preliminary results confirm that the part of the studied plant had a very good antimicrobial activity that was proportional to the serial concentrations of the tested extracts.


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