Antibacterial activities of plant-derived xanthones

2022 ◽  
Author(s):  
Xiaojia Liu ◽  
Jianzhong Shen ◽  
Kui Zhu

The increasing threat to global health posed by antibiotic resistance remains a serious concern. This troublesome scenario has steered a need for the discovery and evaluation of novel antibacterial agents....

2019 ◽  
Vol 20 (7) ◽  
pp. 756-762 ◽  
Author(s):  
Aditi Kaushik ◽  
Manish Kaushik ◽  
Viney Lather ◽  
J.S. Dua

An emerging crisis of antibiotic resistance for microbial pathogens is alarming all the nations, posing a global threat to human health. The production of the metallo-β-lactamase enzyme is the most powerful strategy of bacteria to produce resistance. An efficient way to combat this global health threat is the development of broad/non-specific type of metallo-β-lactamase inhibitors, which can inhibit the different isoforms of the enzyme. Till date, there are no clinically active drugs against metallo- β-lactamase. The lack of efficient drug molecules against MBLs carrying bacteria requires continuous research efforts to overcome the problem of multidrug-resistance bacteria. The present review will discuss the clinically potent molecules against different variants of B1 metallo-β-lactamase.


Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 321
Author(s):  
Shekh Sabir ◽  
Tsz Tin Yu ◽  
Rajesh Kuppusamy ◽  
Basmah Almohaywi ◽  
George Iskander ◽  
...  

The quorum sensing (QS) system in multi-drug-resistant bacteria such as P. aeruginosa is primarily responsible for the development of antibiotic resistance and is considered an attractive target for antimicrobial drug discovery. In this study, we synthesised a series of novel selenourea and thiourea-containing dihydropyrrol-2-one (DHP) analogues as LasR antagonists. The selenium DHP derivatives displayed significantly better quorum-sensing inhibition (QSI) activities than the corresponding sulphur analogues. The most potent analogue 3e efficiently inhibited the las QS system by 81% at 125 µM and 53% at 31 µM. Additionally, all the compounds were screened for their minimum inhibitory concentration (MIC) against the Gram-positive bacterium S. aureus, and interestingly, only the selenium analogues showed antibacterial activity, with 3c and 3e being the most potent with a MIC of 15.6 µM.


Planta Medica ◽  
2020 ◽  
Author(s):  
Violette Hamers ◽  
Clément Huguet ◽  
Mélanie Bourjot ◽  
Aurélie Urbain

AbstractInfectious diseases are among the greatest threats to global health in the 21st century, and one critical concern is due to antibiotic resistance developed by an increasing number of bacterial strains. New resistance mechanisms are emerging with many infections becoming more and more difficult if not impossible to treat. This growing phenomenon not only is associated with increased mortality but also with longer hospital stays and higher medical costs. For these reasons, there is an urgent need to find new antibiotics targeting pathogenic microorganisms such as ESKAPEE bacteria. Most of currently approved antibiotics are derived from microorganisms, but higher fungi could constitute an alternative and remarkable reservoir of anti-infectious compounds. For instance, pleuromutilins constitute the first class of antibiotics derived from mushrooms. However, macromycetes still represent a largely unexplored source. Publications reporting the antibacterial potential of mushroom extracts are emerging, but few purified compounds have been evaluated for their bioactivity on pathogenic bacterial strains. Therefore, the aim of this review is to compile up-to-date data about natural products isolated from fruiting body fungi, which significantly inhibit the growth of ESKAPEE pathogenic bacteria. When available, data regarding modes of action and cytotoxicity, mandatory when considering a possible drug development, have been discussed in order to highlight the most promising compounds.


Author(s):  
Zohor Mohammad Mahdi Alzhrani ◽  
Mohammad Mahboob Alam ◽  
Syed Nazreen

Background: The frequent uses of antimicrobial agents to treat infections in diabetic patients make them more drug resistance than non diabetic patients which accounts for higher mortality rate of diabetic patients. Therefore, it is a necessity today to synthesize new drugs with dual mode of action as antidiabetic and antibacterial agents. In the present work, new derivatives containing thiazolidinedione and 1,3,4-oxadiaozle have been synthesized and screened for PPAR-γ and antibacterial activities. Methods: Compound 5-12 have been synthesized from 2-methoxy benzaldehyde and thiazolidinedione and characterized using different spectroscopic techniques such as IR, NMR and mass spectrometry. These compounds were tested for in vitro PPAR-γ transactivation, PPAR-γ gene expression and antibacterial activities. Finally molecular docking was carried out to see the binding interactions of molecules with the target protein. Results: All the compounds follow Lipinski rule suggesting the synthesized derivatives have good drug likeness properties. Compound 11 and 12 exhibited promising PPAR-γ transactivation with 73.69% and 76.50%, respectively as well as showed significant antibacterial activity with comparable MIC of 3.12 μg/disc to standard drug amoxicillin. The docking result was found to be in consistent with the in vitro PPAR-γ transactivation results. Conclusion: Compounds 11 and 12 can be further investigated as lead molecules for the development of new and effective antidiabetic and antibacterial agents.


Nanomedicine ◽  
2020 ◽  
Vol 15 (5) ◽  
pp. 527-542
Author(s):  
Qianyu Zhang ◽  
Wen Wu ◽  
Jinqiang Zhang ◽  
Xuefeng Xia

Helicobacter pylori is a pathogen that is considered to cause several gastric disorders such as chronic gastritis, peptic ulcer and even gastric carcinoma. The current therapeutic regimens mainly constitute of a combination of several antimicrobial agents and proton pump inhibitors. However, the prevalence of antibiotic resistance has been significantly lowering the cure rates over the years. Nanocarriers possess unique strengths in this regard owing to the fact that they can protect the drugs (such as antibiotics) from the harsh environment in the stomach, penetrate the mucosal barrier and deliver drugs to the desired site. In this review we summarized recent studies of different antibacterial agents orally delivered by nanosized carriers for the eradication of H. pylori.


2017 ◽  
Vol 23 (3) ◽  
pp. 197-203 ◽  
Author(s):  
Shaikha S. Alneyadi ◽  
Anas A. Abdulqader ◽  
Alaa A. Salem ◽  
Ibrahim M. Abdou

Abstract4-Trifluoromethylpyridine derivatives 4–8 represent good candidates for the discovery of new antibacterial agents. Fluorinated pyridine nucleosides 4–7 and non-nucleoside analogues 8a,b were synthesized and evaluated for their antibacterial activities against Staphylococcus aureus, Bacillus infantis, Escherichia coli and Stenotrophomonas maltophilia. The minimum inhibitory concentrations (MICs) of the new nucleosides 4–7 range from 1.3 to 4.9 μg/mL and MICs of fluoroaryl derivatives 8a,b are in the range of 1.8–5.5 μg/mL. Activity of amoxicillin, the reference drug, is 1.0–2.0 μg/mL under similar conditions.


Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1772
Author(s):  
Hui Lu ◽  
Xia Zhou ◽  
Lei Wang ◽  
Linhong Jin

A series of new N-phenylacetamide derivatives containing 4-arylthiazole moieties was designed and synthesized by introducing the thiazole moiety into the amide scaffold. The structures of the target compounds were confirmed by 1H-NMR, 13C-NMR and HRMS. Their in vitro antibacterial activities were evaluated against three kinds of bacteria—Xanthomonas oryzae pv. Oryzae (Xoo), Xanthomonas axonopodis pv. Citri (Xac) and X.oryzae pv. oryzicola (Xoc)—showing promising results. The minimum 50% effective concentration (EC50) value of N-(4-((4-(4-fluoro-phenyl)thiazol-2-yl)amino)phenyl)acetamide (A1) is 156.7 µM, which is superior to bismerthiazol (230.5 µM) and thiodiazole copper (545.2 µM). A scanning electron microscopy (SEM) investigation has confirmed that compound A1 could cause cell membrane rupture of Xoo. In addition, the nematicidal activity of the compounds against Meloidogyne incognita (M. incognita) was also tested, and compound A23 displayed excellent nematicidal activity, with mortality of 100% and 53.2% at 500 μg/mL and 100 μg/mL after 24 h of treatment, respectively. The preliminary structure-activity relationship (SAR) studies of these compounds are also briefly described. These results demonstrated that phenylacetamide derivatives may be considered as potential leads in the design of antibacterial agents.


Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 714 ◽  
Author(s):  
Zheng Jiang ◽  
Junwei Wei ◽  
Yunxiang Liang ◽  
Nan Peng ◽  
Yingjun Li

Antibiotic resistance is becoming the biggest threat to global health. At the same time, phage therapy is witnessing a return of interest. The therapeutic use of bacteriophages that infect and kill bacteria is a suitable strategy to combat antibiotic resistance. Furthermore, bacteriophages are increasingly used in combination with standard antibiotics against drug-resistant pathogens. Interestingly, we found that the engineered mycobacteriophage phAE159 and natural phage D29 cannot infect the Mycobacterium tuberculosis in the presence of kanamycin, hygromycin or streptomycin, but the phage infection was not affected in the presence of spectinomycin. Based on a series of studies and structural analysis of the above four aminoglycoside antibiotics, it could be speculated that the amino sugar group of aminoglycoside might selectively inhibit mycobacteriophage DNA replication. Our discovery that broad-spectrum antibiotics inhibit phage infection is of great value. This study will provide guidance for people to combine phage and antibiotics to treat M. tuberculosis.


1998 ◽  
Vol 61 (10) ◽  
pp. 1378-1380 ◽  
Author(s):  
AMIN ABRAHIM ◽  
ANNA PAPA ◽  
NIKOLAOS SOULTOS ◽  
IOANNIS AMBROSIADIS ◽  
ANTONIS ANTONIADIS

Sixty-five samples of traditionally made fresh sausages obtained from retail shops and butcher shops in northem Greece were screened for the presence of Salmonella spp. and Listeria spp. Salmonella spp. were found in 20% of the samples tested (54% Salmonella typhimurium and 46% Salmonella enteritidis). The prevalence of Listeria spp. in the samples was 26% (12% Listeria monocytogenes, 76% Listeria innocua, and 12% Listeria welshimeri). Nine of 13 Salmonella isolates were found to be resistant to ampicillin and 4 of 13 showed intermediate sensitivity; 1 of 13 was found to be resistant to chloramphenicol and 1 of 13 to tetracycline. Two strains of Salmonella typhimurum were multiresistant (resistant to ampicillin, chloramphenicol, and norfloxacin). All Listeria isolates were sensitive to the antibacterial agents tested that are commonly used for the treatment of human listeriosis.


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