scholarly journals Polyphenol-Rich Larix decidua Bark Extract with Antimicrobial Activity against Respiratory-Tract Pathogens: A Novel Bioactive Ingredient with Potential Pharmaceutical and Nutraceutical Applications

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 789
Author(s):  
Marta Faggian ◽  
Giulia Bernabè ◽  
Sara Ferrari ◽  
Stefano Francescato ◽  
Gianni Baratto ◽  
...  

Larch (Larix decidua) bark is a sawmill waste, traditionally used for antiseptic, expectorant and dermatological (wound healing, eczema, psoriasis) purposes. In this work, we developed a food-grade dry larch bark extract (LBE) from sawmill by-products using hydro-alcoholic extraction. The antibacterial activity of LBE was evaluated against respiratory-tract pathogens, i.e. Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Klebsiella pneumoniae, Pseudomonas aeruginosa and Haemophilus influenza, and it was compared to that of grapefruit seed extract (GSE), a commercially available raw material commonly proposed as antibacterial ingredient for over-the-counter products. Procyanidins (PACs) and other polyphenols contents in LBE were determined by HPLC-FLD-MS and HPLC-DAD-MSn, respectively. The antimicrobial activity of LBE and GSE was assessed using the micro-plate dilution technique in concentration range of 2–200 µg/mL, and the safety of these dosages was assessed in cellular and animal models. LBE showed considerable contents of PACs (15% w/w; especially B-type) and other polyphenols (3.8% w/w), among which the characteristic spiropolyphenols larixinol and epilarixinol were identified, together with the flavonoids isoquercitrin and rutin, already reported as growth inhibitors of different respiratory-tract pathogens. LBE showed higher antimicrobial activity compared to GSE, demonstrated by a growth inhibition range of 10–40% towards five of six strains tested, compared to 10–15% of GSE. These results suggest that LBE may represent a natural and sustainable source of active compounds with antibacterial activity for pharmaceutical and nutraceutical applications.

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.


2018 ◽  
Vol 69 (4) ◽  
pp. 815-822 ◽  
Author(s):  
Lucia Pintilie ◽  
Amalia Stefaniu ◽  
Alina Ioana Nicu ◽  
Maria Maganu ◽  
Miron Teodor Caproiu

A new series of fluoroquinolone compounds have been obtained by Gould-Jacobs method. The compounds have been characterized by physic-chemical methods (elemental analysis, FTIR, NMR, UV-Vis) and by antimicrobial activity against Gram-positive and Gram-negative microorganisms. For the synthesized compounds have been performed calculations of characteristics and molecular properties, using Spartan�14 Software from Wavefunction, Inc. Irvine, CA. and molecular docking studies using CLC Drug Discovery Workbench 2.4 software, to identify and visualize the most likely interaction ligand (fluoroquinolone) with the receptor protein.


2020 ◽  
Vol 17 (5) ◽  
pp. 396-403
Author(s):  
Nalla Krishna Rao ◽  
Tentu Nageswara Rao ◽  
Botsa Parvatamma ◽  
Y. Prashanthi ◽  
Ravi Kumar Cheedarala

Aims: A series of six 4-benzylidene-2-((1-phenyl-3,4-dihydro isoquinoline-2(1H)-yl)methyloxazol- 5(4H)-one derivatives were synthesized by condensation of substituted aryl aldehydes with 2-(2-(1-phenyl-3,4- dihydro isoquinoline-2(1H)-acetamido)acetic acid in the presence of sodium acetate, acetic anhydride and zinc oxide as catalysts. Background: Novel Synthesis of 4-Benzylidene-2-((1-phenyl-3,4-dihy droisoquinoline-2(1H)-yl)methyl)oxazol- 5(4H)-one derivatives using 1,2,3,Tetrahydroisoquinoline and their antimicrobial activity. Objective: The title compounds can be synthesized from 1,2,3,4-tetrahydroisoquinoline. Methods: The target molecules, i.e., 4-benzylidene-2-((1-phenyl-3, 4-dihydro isoquinoline-2(1H)-yl) methyl) oxazol-5(4H)-one derivatives (8a-8f) have been synthesized from 1,2,3,4-tetrahydroisoquinoline which was prepared from benzoic acid in few steps. Results: All the six compounds were evaluated based on advanced spectral data (1H NMR, 13C NMR & LCMS), and the chemical structures of all compounds were determined by elemental analysis. Conclusion: Antibacterial activity of the derivatives was examined for the synthesized compounds and results indicate that compound with bromine substitution has a good activity profile.


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.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ram Prasad ◽  
Vyshnava Satyanarayana Swamy

The unique property of the silver nanoparticles having the antimicrobial activity drags the major attention towards the present nanotechnology. The environmentally nontoxic, ecofriendly, and cost-effective method that has been developed for the synthesis of silver nanoparticles using plant extracts creates the major research interest in the field of nanobiotechnology. The synthesized silver nanoparticles have been characterized by the UV-visible spectroscopy, atomic force microscopy (AFM), and scanning electron microscopy (SEM). Further, the antibacterial activity of silver nanoparticles was evaluated by well diffusion method, and it was found that the biogenic silver nanoparticles have antibacterial activity against Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 29213), Pseudomonas aeruginosa (ATCC 27853), Azotobacter chroococcum WR 9, and Bacillus licheniformis (MTCC 9555).


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.


2005 ◽  
Vol 60 (5-6) ◽  
pp. 385-388 ◽  
Author(s):  
Rubén García ◽  
Cesia Cayunao ◽  
Ronny Bocic ◽  
Nadine Backhouse ◽  
Carla Delporte ◽  
...  

Bioassay-directed fractionation for the determination of antimicrobial activity of Uncaria tomentosa, has led to the isolation of isopteropodine (0.3%), a known Uncaria pentacyclic oxindol alkaloid that exhibited antibacterial activity against Gram positive bacteria.


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