ANTIMICROBIAL ACTIVITY AND IDENTIFICATION OF POTENTIAL ETHANOLIC ANTIMICROBIAL COMPOUNDS FROM THE MEDICINAL PLANT PISONIA GRANDIS R.Br

2017 ◽  
pp. 1686-1700
Author(s):  
G. Pradheesh
Keyword(s):  
Antimicrobial Activity ◽  
Medicinal Plant ◽  
Antimicrobial Compounds ◽  
Pisonia Grandis

ANTIMICROBIAL ACTIVITIES OF METHANOL EXTRACT FROM UNIDENTIFIED SPONGE ASSOCIATED BACTERIA IN LEMUKUTAN ISLAND, KALIMANTAN BARAT

2009 ◽  
Vol 1 (2) ◽  
Author(s):  
Risa Nofiani ◽  
Siti Nurbetty ◽  
Ajuk Sapar
Keyword(s):  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Pathogenic Bacteria ◽  
Methanol Extract ◽  
Agar Medium ◽  
Antimicrobial Activities ◽  
Antimicrobial Compounds ◽  
Associated Bacteria ◽  
Minimum Inhibitory Concentrations ◽  
Sponge Associated Bacteria

<p>The increase of issues on the antibiotics resistant pathogenic bacteria has triggered high exploration for new antimicrobial compounds. One of the potential sources is sponge-associated bacteria. The aim of this study was to get sponge-associated bacteria extract containing antimicrobial activities. On the basis screening of antimicrobial activity using by streaking on agar medium, there were two potential isolates with antimicrobial activities namely LCS1 and LCS2. The two isolates were cultivated,then secondary metabolite product were extracted using methanol as a solvent. Minimum inhibitory concentrations (MICs) of extract LCS 1 were 1,000 μg/well for S. aureus, 950 μg/well for Salmonella sp.and 800 μg/well for Bacillus subtilis. Minimum inhibitory concentrations of extract LCS 2 were 500 μg/well for S. aureus, 1,050 μg/well for Salmonella sp., 750 μg/well for Bacillus subtilis, 350 μg/well for P. aeruginosa, 750 μg/sumur terhadap B. subtilis. Based on the MIC values, the two assay extracts have a relatively low antimicrobial activity.</p> <p>Keywords:Antimicrobial,Sponges associated bacteria,MICs</p>

scholarly journals Comparison of a Short Linear Antimicrobial Peptide with Its Disulfide-Cyclized and Cyclotide-Grafted Variants against Clinically Relevant Pathogens

2021 ◽  
Vol 9 (6) ◽  
pp. 1249
Author(s):  
Johannes Koehbach ◽  
Jurnorain Gani ◽  
Kai Hilpert ◽  
David J Craik
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Peptide ◽  
Human Serum ◽  
World Health ◽  
Resistant Bacteria ◽  
Moderate Activity ◽  
Antimicrobial Compounds ◽  
Strong Activity ◽  
Linear Peptide ◽  
Linear Version

According to the World Health Organization (WHO) the development of resistance against antibiotics by microbes is one of the most pressing health concerns. The situation will intensify since only a few pharmacological companies are currently developing novel antimicrobial compounds. Discovery and development of novel antimicrobial compounds with new modes of action are urgently needed. Antimicrobial peptides (AMPs) are known to be able to kill multidrug-resistant bacteria and, therefore, of interest to be developed into antimicrobial drugs. Proteolytic stability and toxicities of these peptides are challenges to overcome, and one strategy frequently used to address stability is cyclization. Here we introduced a disulfide-bond to cyclize a potent and nontoxic 9mer peptide and, in addition, as a proof-of-concept study, grafted this peptide into loop 6 of the cyclotide MCoTI-II. This is the first time an antimicrobial peptide has been successfully grafted onto the cyclotide scaffold. The disulfide-cyclized and grafted cyclotide showed moderate activity in broth and strong activity in 1/5 broth against clinically relevant resistant pathogens. The linear peptide showed superior activity in both conditions. The half-life time in 100% human serum was determined, for the linear peptide, to be 13 min, for the simple disulfide-cyclized peptide, 9 min, and, for the grafted cyclotide 7 h 15 min. The addition of 10% human serum led to a loss of antimicrobial activity for the different organisms, ranging from 1 to >8-fold for the cyclotide. For the disulfide-cyclized version and the linear version, activity also dropped to different degrees, 2 to 18-fold, and 1 to 30-fold respectively. Despite the massive difference in stability, the linear peptide still showed superior antimicrobial activity. The cyclotide and the disulfide-cyclized version demonstrated a slower bactericidal effect than the linear version. All three peptides were stable at high and low pH, and had very low hemolytic and cytotoxic activity.

Antimicrobial activity of methanolic extracts of indigenous traditional Indian folk Medicinal Plant, Gnaphalium polycaulon

2015 ◽  
Vol 9 (1) ◽  
pp. 39 ◽  
Author(s):  
Thayumanavan Thangavelu ◽  
Jinu Udayabhanu ◽  
SenthilMurugan Thangavel ◽  
Shanmugapriya Kaminidevi
Keyword(s):  
Antimicrobial Activity ◽  
Medicinal Plant ◽  
Methanolic Extracts

scholarly journals Highlighting the Biotechnological Potential of Deep Oceanic Crust Fungi through the Prism of Their Antimicrobial Activity

Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 411
Author(s):  
Maxence Quemener ◽  
Marie Dayras ◽  
Nicolas Frotté ◽  
Stella Debaets ◽  
Christophe Le Meur ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Oceanic Crust ◽  
Gene Clusters ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Antimicrobial Compounds ◽  
Human Pathogens ◽  
Biotechnological Potential ◽  
Fungal Isolates

Among the different tools to address the antibiotic resistance crisis, bioprospecting in complex uncharted habitats to detect novel microorganisms putatively producing original antimicrobial compounds can definitely increase the current therapeutic arsenal of antibiotics. Fungi from numerous habitats have been widely screened for their ability to express specific biosynthetic gene clusters (BGCs) involved in the synthesis of antimicrobial compounds. Here, a collection of unique 75 deep oceanic crust fungi was screened to evaluate their biotechnological potential through the prism of their antimicrobial activity using a polyphasic approach. After a first genetic screening to detect specific BGCs, a second step consisted of an antimicrobial screening that tested the most promising isolates against 11 microbial targets. Here, 12 fungal isolates showed at least one antibacterial and/or antifungal activity (static or lytic) against human pathogens. This analysis also revealed that Staphylococcus aureus ATCC 25923 and Enterococcus faecalis CIP A 186 were the most impacted, followed by Pseudomonas aeruginosa ATCC 27853. A specific focus on three fungal isolates allowed us to detect interesting activity of crude extracts against multidrug-resistant Staphylococcus aureus. Finally, complementary mass spectrometry (MS)-based molecular networking analyses were performed to putatively assign the fungal metabolites and raise hypotheses to link them to the observed antimicrobial activities.

scholarly journals Antimicrobial activity of aqueous and organic extracts of a Saudi medicinal plant: Rumex nervosus

2015 ◽  
Vol 7 (4) ◽  
pp. 300 ◽  
Author(s):  
Abdul RahmanK Al-Asmari ◽  
YunusM Siddiqui ◽  
MdTanwir Athar ◽  
Ahmed Al-Buraidi ◽  
AS Al-Eid ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Medicinal Plant ◽  
Organic Extracts

scholarly journals Correlation between the Antimicrobial Activity and Metabolic Profiles of Cell Free Supernatants and Membrane Vesicles Produced by Lactobacillus reuteri DSM 17938

2020 ◽  
Vol 8 (11) ◽  
pp. 1653
Author(s):  
Alessandro Maccelli ◽  
Simone Carradori ◽  
Valentina Puca ◽  
Francesca Sisto ◽  
Paola Lanuti ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Lactobacillus Reuteri ◽  
Membrane Vesicles ◽  
Metabolic Profiles ◽  
Ion Cyclotron Resonance ◽  
Antimicrobial Compounds ◽  
Ionization Source ◽  
Gram Positive ◽  
Gram Negative ◽  
Broth Microdilution Method

The aim of the work is to assess the antimicrobial activities of Cell Free Supernatants (CFS) and Membrane Vesicles (MVs), produced by Lactobacillus reuteri DSM 17938, versus Gram-positive and Gram-negative bacteria and investigate their metabolic profiles. The Minimum Inhibitory Concentration was determined through the broth microdilution method and cell proliferation assay while the Minimum Bactericidal Concentration was determined by Colony Forming Units counts. The characteristics of the antimicrobial compounds were evaluated by pH adjustments, proteinase treatment, and size fractionation of the CFS. The cytotoxicity of CFS was tested on two human cell lines. A detailed snapshot of the L. reuteri metabolism was attained through an untargeted metabolic profiling by means of high resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) coupled with Electrospray Ionization Source (ESI). The results showed (i) a greater efficacy of CFS and its fractions towards Gram-negative compared to Gram-positive bacteria; (ii) an antimicrobial effect related to pH-dependent compounds but not to MVs; (iii) a molecular weight < 3 KDa as well as an a non-proteinaceous nature of the antimicrobial compounds; and (iv) more than 200 and 500 putative metabolites annotated in MVs and supernatants, covering several classes of metabolites, including amino acids, lipids, fatty and organic acids, polyalcohols, nucleotides, and vitamins. Some putative compounds were proposed not only as characteristic of specific fractions, but also possibly involved in antimicrobial activity.

scholarly journals Phytochemical Screening of Quaking Aspen (Populus tremuloides) Extracts by UPLC-QTOF-MS and Evaluation of their Antimicrobial Activity

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1739 ◽  
Author(s):  
Annabelle St-Pierre ◽  
Dorian Blondeau ◽  
André Lajeunesse ◽  
Julien Bley ◽  
Nathalie Bourdeau ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Populus Tremuloides ◽  
Antimicrobial Agents ◽  
Methanol Extract ◽  
Antimicrobial Properties ◽  
Water Extract ◽  
Pathogen Resistance ◽  
Quaking Aspen ◽  
Antimicrobial Compounds ◽  
Minimal Inhibition Concentration

The continual emergence of pathogen resistance is a recurring challenge and pushes for the development of antimicrobial compounds. Here, we investigated compounds from quaking aspen trees (Populus tremuloides) as potential antimicrobial agents. Several extractions using different solvents were realized, and corresponding antimicrobial activity was tested against eight microorganisms. Results revealed that polar extraction solvents including water, ethanol and methanol gave the best extraction yields (>15.07%). Minimal inhibition concentration (MIC) and minimal bactericidal/fungicidal concentration (MBC/MFC) demonstrated that water extracts had the best antimicrobial activity by a weak to moderate inhibition of growth of all eight tested microorganisms in addition to having a bactericidal effect on three of them. The quaking aspen methanol extract also displayed antimicrobial activity but to a lower level than the water extract. Ultra-performance liquid chromatography quadrupole time-of flight mass spectrometry (UPLC-QTOF-MS) analysis led to the identification of 92 compounds, mainly polyphenols in both extracts, with 22 molecules previously known for their antimicrobial properties. According to the relative abundance, 4-hydroxybenzaldehyde (5.44% in methanol extract) and kaempferol (5.03% in water extract) were the most abundant antimicrobial compounds. Among antimicrobial molecules identified, nine were from the flavonoid family. The results of our study demonstrate the interest of using quaking aspen as source of antimicrobial compounds.

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