scholarly journals Bioactive Ascochlorin Analogues from the Marine-Derived Fungus Stilbella fimetaria

Marine Drugs ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 46
Author(s):  
Karolina Subko ◽  
Sara Kildgaard ◽  
Francisca Vicente ◽  
Fernando Reyes ◽  
Olga Genilloud ◽  
...  

The marine-derived fungus Stilbella fimetaria is a chemically talented fungus producing several classes of bioactive metabolites, including meroterpenoids of the ascochlorin family. The targeted dereplication of fungal extracts by UHPLC-DAD-QTOF-MS revealed the presence of several new along with multiple known ascochlorin analogues (19–22). Their structures and relative configuration were characterized by 1D and 2D NMR. Further targeted dereplication based on a novel 1,4-benzoquinone sesquiterpene derivative, fimetarin A (22), resulted in the identification of three additional fimetarin analogues, fimetarins B–D (23–25), with their tentative structures proposed from detailed MS/HRMS analysis. In total, four new and eight known ascochlorin/fimetarin analogues were tested for their antimicrobial activity, identifying the analogues with a 5-chloroorcylaldehyde moiety to be more active than the benzoquinone analogue. Additionally, the presence of two conjugated double bonds at C-2′/C-3′ and C-4′/C-5′ were found to be essential for the observed antifungal activity, whereas the single, untailored bonds at C-4′/C-5′ and C-8′/C-9′ were suggested to be necessary for the observed antibacterial activity.

2019 ◽  
Vol 70 (10) ◽  
pp. 3603-3610
Author(s):  
Madalina Mihalache ◽  
Cornelia Guran ◽  
Aurelia Meghea ◽  
Vasile Bercu ◽  
Ludmila Motelica ◽  
...  

The three copper complexes having a-ketoglutaric acid (H2A) and 1- (o-tolyl) biguanide (TB) ligands have been synthesized and characterized. The proposed formulas for these complexes are: [Cu(TB)(HA)]Cl (C1), [Cu(TB)(HA)CH3COO]�H2O (C2) and [Cu(TB)(HA)](NO3) (C3) where HA represents deprotonated H2A. The complexes obtained were tested for antibacterial activity against Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853, antifungal activity on Candida albicans ATCC 10231 and antitumor activity on HeLa tumor cells. Due to the antitumor, antifungal, antimicrobial activity and inhibition of inert substrate adhesion, complexes synthesized could be used for potential therapeutic applications.


Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4383
Author(s):  
Barbara Lapinska ◽  
Aleksandra Szram ◽  
Beata Zarzycka ◽  
Janina Grzegorczyk ◽  
Louis Hardan ◽  
...  

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S.mutans and L.acidophilus, as well as antifungal effect on C.albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S.mutans and L.acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S.mutans. All tested EOs exhibited antifungal activity against C.albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S.mutans and C.albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L.acidophilus.


2017 ◽  
Vol 7 (4) ◽  
pp. 420 ◽  
Author(s):  
Adriana Favaretto ◽  
Fabiana Tonial ◽  
Charise Dallazem Bertol ◽  
Simone Meredith Scheffer-Basso

This study aimed to evaluate tough lovegrass leaf and root extracts antimicrobial activity. The extracts (plant material: solvent, 1:10) were prepared by maceration with methanol:water (1:1) during ten days followed by a concentration in a rotary evaporator under reduced pressure. The extracts were resuspended in water containing 1% of dimethylsulfoxide (DMSO) to obtain a final concentration of 100 mg/mL and then filtered through a sterilizing membrane with 0.22μm. The antibacterial activity of the leaf and root extracts were evaluated against pathogenic and phytopathogenic bacteria by agar well diffusion and microdilution broth methods for the minimum inhibitory concentrations (MIC) determination. The antifungal activity of tough lovegrass leaf and root extracts were evaluated by micelial growth inhibition and conidial germination inhibition. The extracts presented low antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, and Xanthomonas translucens, but the leaf extracts presented significant antifungal activity against the phytopathogenic fungus Drechslera tritici-repentis. The results support the continuity of the study in improving the effectiveness of the active extract for a possible use in pharmacology and agronomy and in attempting to determine the probable active antimicrobial compound.


2020 ◽  
Vol 13 (9) ◽  
pp. 229
Author(s):  
Volodymyr Horishny ◽  
Victor Kartsev ◽  
Vasyl Matiychuk ◽  
Athina Geronikaki ◽  
Petrou Anthi ◽  
...  

Herein we report the design, synthesis, computational, and experimental evaluation of the antimicrobial activity of fourteen new 3-amino-5-(indol-3-yl) methylene-4-oxo-2-thioxothiazolidine derivatives. The structures were designed, and their antimicrobial activity and toxicity were predicted in silico. All synthesized compounds exhibited antibacterial activity against eight Gram-positive and Gram-negative bacteria. Their activity exceeded those of ampicillin and (for the majority of compounds) streptomycin. The most sensitive bacterium was S. aureus (American Type Culture Collection ATCC 6538), while L. monocytogenes (NCTC 7973) was the most resistant. The best antibacterial activity was observed for compound 5d (Z)-N-(5-((1H-indol-3-yl)methylene)-4-oxo-2-thioxothiazolidin-3-yl)-4-hydroxybenzamide (Minimal inhibitory concentration, MIC at 37.9–113.8 μM, and Minimal bactericidal concentration MBC at 57.8–118.3 μM). Three most active compounds 5d, 5g, and 5k being evaluated against three resistant strains, Methicillin resistant Staphilococcus aureus (MRSA), P. aeruginosa, and E. coli, were more potent against MRSA than ampicillin (MIC at 248–372 μM, MBC at 372–1240 μM). At the same time, streptomycin (MIC at 43–172 μM, MBC at 86–344 μM) did not show bactericidal activity at all. The compound 5d was also more active than ampicillin towards resistant P. aeruginosa strain. Antifungal activity of all compounds exceeded those of the reference antifungal agents bifonazole (MIC at 480–640 μM, and MFC at 640–800 μM) and ketoconazole (MIC 285–475 μM and MFC 380–950 μM). The best activity was exhibited by compound 5g. The most sensitive fungal was T. viride (IAM 5061), while A. fumigatus (human isolate) was the most resistant. Low cytotoxicity against HEK-293 human embryonic kidney cell line and reasonable selectivity indices were shown for the most active compounds 5d, 5g, 5k, 7c using thiazolyl blue tetrazolium bromide MTT assay. The docking studies indicated a probable involvement of E. coli Mur B inhibition in the antibacterial action, while CYP51 inhibition is likely responsible for the antifungal activity of the tested compounds.


2005 ◽  
Vol 2 (1) ◽  
pp. 1-5 ◽  
Author(s):  
R. U. Roy ◽  
A. R. R. Desai ◽  
K. R. Desai

Several 3-(4'-nitrophenyl)-4-(4"-chloro benzamido)-5-substituted phenyl)-4H-1,2,4-triazole (3a-3e) and 3-(4'-nitrophenyl)-4-(4"-methyl benzenesulphonamido)-5-substituted phenyl)-4H-1,2,4-triazole (4a-4e) have been synthesised. Representative compounds were screened for antibacterial, antifungal activity. Most of them showed significant antibacterial activity.


2019 ◽  
Vol 84 (12) ◽  
pp. 1355-1365 ◽  
Author(s):  
Jovana Stankovic ◽  
Miroslav Novakovic ◽  
Vele Tesevic ◽  
Ana Ciric ◽  
Marina Sokovic ◽  
...  

This study was performed to determine the main antibacterial compounds of the essential oil (??) of saltmarsh plant Artemisia santonicum (Asteraceae). The combination of HPTLC and direct bioautography was used for the activity guided isolation of isogeranic acid as the main antibacterial constituent with remarkable antimicrobial activity, although it was the minor component of the EO, present only in 0.2 %, as calculated from GC/FID. Its structure was determined by 1D- and 2D-NMR and GC?MS techniques. Antibacterial activity of isogeranic acid against all tested bacteria was significantly higher than EO and even than both controls streptomycin and ampicillin. In further investigation of antibiofilm and antiquorum sensing activity EO exhibited the best inhibition of the biofilm formation at 1/8 minimal inhibitory concentration (MIC) and isogeranic acid at 1/2 MIC. Both EO and isogeranic acid possessed pyocyanin inhibitory activity showing the reduction of pigment at 60.6 and 62.8 %, respectively, at 1/2 MIC concentrations.


2020 ◽  
Vol 49 (2) ◽  
Author(s):  
Emir Horozić

Spring saffron (lat. Crocus vernus (L.)Hill) is a perennial from the Iridaceae family. Purple or white coloured flowers bloom in the early spring. Saffron is commonly used in cookery, but because of its healing properties, crocus is also used in medicine for improving blood circulation, treating the cardiovascular diseases, preventing tumour and healing skin diseases. This research aimed to determine the influence of solvents (water, ethanol and acetone) on antioxidative, antimicrobial activity and the content of biologically important compounds, such as phenols and flavonoids in saffron. FRAP and DPPH methods were used to examine antioxidative activity. Antibacterial activity was analysed by using diffusion technique on bacterial strains of Escherichia coli, Enterococcus faecalis, Staphylococcus aureus, Bacillus subtilis, Listeria monocytogenes, and Pseudomonas aeruginosa. Antifungal activity was examined on Candida albicans. The results showed that the ethanol extracts have the highest antioxidant activity and the aqueous extracts have the lowest one. None of the tested extracts showed antibacterial activity, but aqueous extracts and ethanolic extract of saffron, obtained by maceration, showed antifungal activity.


2017 ◽  
Vol 9 (3) ◽  
pp. 297-306 ◽  
Author(s):  
R. Ali ◽  
A. Rahim ◽  
A. Islam

7-Hydroxy-3',4'-methylenedioxy- and 7-benzyloxy-3',4'-methylenedioxy flavanones have been synthesized starting from 2,4-dihydroxyacetophenone. Subsequently biocidal activities of the flavanones have been investigated along with their corresponding chalcones against some bacterial and fungal strains. 2'-Hydroxy-4'-benzyloxy-3,4-methylenedioxy chalcone (5) and its corresponding flavanone (7) showed good antibacterial and antifungal activities against some selected bacterial and fungal strains. On the other hand, 2',4'-dihydroxy-3,4-methylenedioxy chalcone (4) showed no antibacterial and antifungal activities while its corresponding flavanone (6) showed a little antibacterial activity only at higher concentration but did not show antifungal activity. The synthesized chalcones and flavanones have been characterized using UV-Vis, IR and 1H NMRspectral data together with elemental analysis.


2015 ◽  
Vol 51 (4) ◽  
pp. 861-867 ◽  
Author(s):  
Roosevelt Albuquerque Gomes ◽  
Yanna Carolina Ferreira Teles ◽  
Fillipe de Oliveira Pereira ◽  
Luis Alberto de Sousa Rodrigues ◽  
Edeltrudes de Oliveira Lima ◽  
...  

abstract Sidastrum micranthum (A. St.-Hil.) Fryxell, a member of the Malvaceae family, is called malva preta in Brazil. As this species is commonly used to treat bronchitis, cough, and asthma, better knowledge of its chemical compounds is important. The phytochemical study of its hexane extract, using chromatographic techniques, led to isolation of six compounds: the triterpene isoarborinol, a mixture of sitosterol and stigmasterol, sitosterol-3-O-β-D-glucopyranoside, pheophytin a, and 132-hydroxy-(132-S)-pheophytin a. Structural identification of these compounds was carried out using spectroscopic methods such as IR and 1D and 2D NMR (HOMOCOSY, HMQC, HMBC, and NOESY). Compounds isolated from S. micranthum were screened for their in vitro antifungal and antibacterial activity against twenty fungal and bacterial standard strains. Pheophytin a exhibited antimicrobial action against all microorganisms tested.


2021 ◽  
Vol 11 (2) ◽  
pp. 237-240
Author(s):  
Neha Choudhary ◽  
Narinder Singh ◽  
Ajeet Pal Singh ◽  
Amar Pal Singh

Maslinic Acid a characteristic compound of the triterpenoid bunch got from olive which forestalls the age of favorable to fiery cytokines and oxidative pressure, found in an assortment of common sources, going from home grown cures utilized in traditional medicine to consumable vegetables and organic products present in the Mediterranean eating routine. A few investigations have demonstrated that maslinic acid a wide scope of pharmacological effects such as Antimalarial Effect, Anti-Proliferative Activity, Antitumor Activity, Antifungal Activity, Antibacterial Activity, Anti-diabetic Effect, Antioxidant effect, Anti-inflammatory Activity, Cardio protective effect, Neuroprotection effect, Antiviral Activity, Antimicrobial Activity. Keywords:  Maslinic acid, Triterpene, edible source, Pharmacological Effects


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