scholarly journals Lichen Xanthones as Models for New Antifungal Agents

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2617 ◽  
Author(s):  
Diana Resende ◽  
Patrícia Pereira-Terra ◽  
Ângela Inácio ◽  
Paulo Costa ◽  
Eugénia Pinto ◽  
...  

Due to the emergence of multidrug-resistant pathogenic microorganisms, the search for new antimicrobial compounds plays an important role in current medicinal chemistry research. Inspired by lichen antimicrobial xanthones, a series of novel chlorinated xanthones was prepared using five chlorination methods (Methods A–E) to obtain different patterns of substitution in the xanthone scaffold. All the synthesized compounds were evaluated for their antimicrobial activity. Among them, 3-chloro-4,6-dimethoxy-1-methyl-9H-xanthen-9-one 15 showed promising antibacterial activity against E. faecalis (ATCC 29212 and 29213) and S. aureus ATCC 29213. 2,7-Dichloro-3,4,6-trimethoxy-1-methyl-9H-xanthen-9-one 18 revealed a potent fungistatic and fungicidal activity against dermatophytes clinical strains (T. rubrum, M. canis, and E. floccosum (MIC = 4–8 µg/mL)). Moreover, when evaluated for its synergistic effect for T. rubrum, compound 18 exhibited synergy with fluconazole (ΣFIC = 0.289). These results disclosed new hit xanthones for both antibacterial and antifungal activity.

2009 ◽  
Vol 63 (5) ◽  
Author(s):  
Gülşah Kurt ◽  
Fatih Sevgi ◽  
Bedrettin Mercimek

AbstractIn this study, new benzoylthiourea derivatives, (E)-N-[(2-benzamidomethyleneamino)ethylcarbamothioyl]benzamide H3L′, N-(1-(3-benzoylthioureido)propan-2-ylcarbamothioyl)-benzamide H4L″, (E)-N-[4-(benzamidomethyleneamino)phenylcarbamothioyl]benzamide H3L‴, were synthesized. Structures of the compounds were identified by spectroscopic techniques. In addition, all synthesized compounds were evaluated for in vitro antibacterial and antifungal activity. Compound H3L‴ exhibited antibacterial activity.


2015 ◽  
Vol 80 (7) ◽  
pp. 839-852 ◽  
Author(s):  
Nina Bozinovic ◽  
Irena Novakovic ◽  
Sladjana Kostic-Rajacic ◽  
Igor Opsenica ◽  
Bogdan Solaja

A series of new 5H-pyridobenzazepine and pyridobenzothiepine derivatives was synthesized by Pd-catalyzed formation of C-N and C-S bonds. All synthesized compounds were tested for their in vitro antimicrobial activity. The 5H-pyridobenzazepine derivatives showed better antibacterial and antifungal activity than corresponding 5H-dipyridoazepine analogs. Among the synthesized azepines, derivative 8 displayed potent activity against tested bacteria (MIC = 39-78 ?g/mL), while azepine 12 showed promising antifungal activity (MIC = 156-313 ?g/mL). The synthesized thiepine derivatives exhibited weak antibacterial activity, but showed pronounced antifungal activity.


Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 411
Author(s):  
Maxence Quemener ◽  
Marie Dayras ◽  
Nicolas Frotté ◽  
Stella Debaets ◽  
Christophe Le Meur ◽  
...  

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.


2020 ◽  
Vol 8 (6) ◽  
pp. 179-187
Author(s):  
Titik Taufikurohmah ◽  
Tasha Anandya Tantyani

This Research on the antibacterial and antifungal activity of nanosilver against Neisseria gonorrhoeae and Candida albincas fungi has been carried out. The purpose of this study was to determine antibacterial activity of nanosilver against Neisseria gonorrhoeae and antifungal activity against Candida albincas. Synthesis Nanosilver uses bottom up method and characterized using UV-Vis Spectrophotometer. Nanosliver concentrations used were 30, 40, 50, and 60 ppm. Antibacterial and antifungal activity tests using disk diffusion method. Observations obtained in form of the presence or absence of clear zones formed around paper discs indicate the inhibition of nanosilver on microbial growth. The results of testing the antifungal activity of Candida albicans on nanosilver with concentrations of 30, 40, 50 and 60 ppm resulted in clear zones of 9.73 nm, 11.46 nm, 11.93 nm, and 13 nm with fungal inhibition response categories is medium and strong. The results antibacterial activity test of Neisseria gonorrhoeae on nanosilver with concentrations of 30, 40, 50 and 60 ppm did not show any clear zone around the disc, it showed that nanosilver in this study did not have antibacterial activity against Neisseria gonorrhoeae.


2020 ◽  
Vol 8 (6) ◽  
pp. 188-195
Author(s):  
Titik Taufikurohmah ◽  
Fadlilah Gita Shalli ◽  
Suyatno ◽  
Eka Apriyosa

Background: Alum has many functions in various fields such as an astringent substance has the potential to inhibit the growth of microorganisms. This study aims to know the antifungal and antibacterial activity against C.albicans and N.gonorrheae which can be used as medicine preparation for vaginal discharge. These microbes are pathogenic microorganisms commonly found in the vagina. Method: The method used is the disk diffusion which is based on a clear zone area to determine the inhibition. Variation concentration of alum used is 2.5; 5; 10; 15; 20 and 25%. Results: The results showed that alum has antimicrobial activity against pathogenic microbes, namely C.albicans and N.gonorrhea. This is indicated by the presence of clear zones formed in the area of paper disks. Concentrations of 20% and 25% have moderate antimicrobial activity. An increase in concentration in alum shows that the diameter of the clear zone that is formed is also getting bigger. Conclusions: In this study, it can be concluded that alum is proven to have antifungal and antibacterial activity against pathogenic microbes that live in the vagina. So, it has the potential to become one of the medicine compositions for vaginal discharge.


2021 ◽  
Vol 2 (2) ◽  
pp. 93-103
Author(s):  
Nathaniel Hiwandika ◽  
Susana Elya Sudrajat ◽  
Ika Rahayu

Cloves is one of the native Indonesian plants and is used in many aspects of life. Cloves are used in multiple industries and as detergents, soaps, perfumes, food seasonings, aromatherapy, etc. Cloves are mainly used for ingredients in kretek cigarettes in Indonesia. Various studies of cloves reported they have good pharmacological and therapeutic effects. The main compounds of clove extract are eugenol and β-caryophyllene, which are powerful antibacterial and antifungal agents. The clove ethanolic extract showed the activity to inhibit Gram positive and negative bacteria such as B. cereus, S. aureus, E. coli, P. aeruginosa, S. pneumoniae, S. aureus, S. epidermidis, A. hydrophila, K. pneumoniae, P. gingivalis, and P. mirabilis. Clove essential oil has shown the ability to inhibit the growth of V. inaequalis, C. albicans, C. glabrata, and C. tropicalis. Cloves extract can be used as an essential ingredient of various medicines. However, it requires further research and trials.


2010 ◽  
Vol 76 (15) ◽  
pp. 4969-4976 ◽  
Author(s):  
Kerstin Engelhardt ◽  
Kristin F. Degnes ◽  
Michael Kemmler ◽  
Harald Bredholt ◽  
Espen Fj�rvik ◽  
...  

ABSTRACT Twenty-seven marine sediment- and sponge-derived actinomycetes with a preference for or dependence on seawater for growth were classified at the genus level using molecular taxonomy. Their potential to produce bioactive secondary metabolites was analyzed by PCR screening for genes involved in polyketide and nonribosomal peptide antibiotic synthesis. Using microwell cultures, conditions for the production of antibacterial and antifungal compounds were identified for 15 of the 27 isolates subjected to this screening. Nine of the 15 active extracts were also active against multiresistant Gram-positive bacterial and/or fungal indicator organisms, including vancomycin-resistant Enterococcus faecium and multidrug-resistant Candida albicans. Activity-guided fractionation of fermentation extracts of isolate TFS65-07, showing strong antibacterial activity and classified as a Nocardiopsis species, allowed the identification and purification of the active compound. Structure elucidation revealed this compound to be a new thiopeptide antibiotic with a rare aminoacetone moiety. The in vitro antibacterial activity of this thiopeptide, designated TP-1161, against a panel of bacterial strains was determined.


2018 ◽  
Vol 23 ◽  
pp. 2515690X1775131 ◽  
Author(s):  
Farhad Sharafati Chaleshtori ◽  
Mohamad Saholi ◽  
Reza Sharafati Chaleshtori

This research was aimed at investigating the antioxidant and antibacterial activity of Bunium persicum, Eucalyptus globulus, and rose water on multidrug-resistant Listeria species. The antibiotic resistance of Listeria spp obtained from seafood samples were determined by the Kirby-Bauer method. The antioxidant and antibacterial activity of the essential oils and extracts were evaluated using ferric reducing antioxidant power and microdilution methods, respectively. A total 2 samples (1.88%) were positive for Listeria spp. L monocytogenes was found to be resistant to ampicillin, amoxicillin/clavulanic acid, penicillin, vancomycin, and kanamycin. B persicum essential oil showed the greatest antioxidant activity (248.56 ± 1.09 µM Fe2+/g). The E globulus essential oil showed consistently strong antimicrobial activity against L monocytogenes and L grayi, while rose water showed no antimicrobial activity against any of the tested bacterial strains. The results showed that after adding the B persicum and E globulus essential oils to bacteria, the cell components’ release increased significantly.


Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 47 ◽  
Author(s):  
Phuong-Y Mai ◽  
Marceau Levasseur ◽  
Didier Buisson ◽  
David Touboul ◽  
Véronique Eparvier

The emergence of multidrug resistant bacterial pathogens and the increase of antimicrobial resistance constitutes a major health challenge, leading to intense research efforts being focused on the discovery of novel antimicrobial compounds. In this study, endophytes were isolated from different parts of Sandwithia guyanensis plant (leaves, wood and latex) belonging to the Euphorbiaceae family and known to produce antimicrobial compounds, and chemically characterised using Molecular Network in order to discover novel antimicrobial molecules. One fungal endophyte extract obtained from S. guyanensis latex showed significant antimicrobial activity with Minimal Inhibitory Concentration on methicillin-resistant Staphylococcus aureus at 16 µg/mL. The chemical investigation of this fungus (Lecanicillium genus) extract led to the isolation of 5 stephensiolides compounds, four of which demonstrated antibacterial activity. Stephensiolide I and G showed the highest antibacterial activity on MRSA with a MIC at 4 and 16 µg/mL respectively.


Sign in / Sign up

Export Citation Format

Share Document