Synthesis and Reactivity of Dihalofuranones

2021 ◽  
Vol 18 ◽  
Author(s):  
Thérèse A. Lyons ◽  
Cormac G. M. Gahan ◽  
Timothy P. O 'Sullivan
Keyword(s):  
Antimicrobial Activity ◽  
Maleic Anhydride ◽  
Bacterial Species ◽  
Phenylboronic Acid ◽  
Microwave Assisted ◽  
Autoinducer 2 ◽  
Quorum Sensing Inhibitors ◽  
Anti Cancer ◽  
Halogenated Furanones ◽  
High Stereoselectivity

Background: Halogenated furanones have been found to act as potent quorum sensing inhibitors in several bacterial species. It is believed that dihalofuranones covalently bind to the LuxS enzyme, which is necessary for autoinducer-2 synthesis. In addition to their antimicrobial activity, halogenated furanones also possess anti-cancer, antioxidant, and depigmentation properties. However, traditional routes to these compounds are low-yielding and capricious. Objective: This study aimed at investigating higher-yielding preparations of gem-dihalofuranones and comparing their reactivity using Suzuki chemistry. Methods: Ramirez dibromoolefination of maleic anhydride was optimised using a variety of conditions. A similar route was investigated for the preparation of bromofluorofuranones and dichlorofuranones. The conversion of a dichlorofuranone to the corresponding iodofuranone derivatives using microwave-assisted Finkelstein chemistry was also studied. Lastly, the reactivity of the different dihalofuranones was compared by Pd-mediated coupling with phenylboronic acid. Results: A higher-yielding, concise synthesis of dibromofuranones was developed using a modified Ramirez reaction. Additionally, a telescoped preparation of dichlorofuranone proved higher yielding than previous approaches. Bromine- and iodine-substituted dihalofuranones proved more reactive than their chlorine-substituted analogues. Conclusion: Higher yielding routes to bromine-, fluorine-, chlorine- and iodine-containing dihalofuranones were successfully developed. Suzuki couplings of gem-dihalofuranones were found to proceed with high stereoselectivity.

scholarly journals Exploring Phenolic Compounds as Quorum Sensing Inhibitors in Foodborne Bacteria

2021 ◽  
Vol 12 ◽  
Author(s):  
Catarina Angeli Santos ◽  
Emília Maria França Lima ◽  
Bernadette Dora Gombossy de Melo Franco ◽  
Uelinton Manoel Pinto
Keyword(s):  
Antimicrobial Activity ◽  
Phenolic Compounds ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Resistant Bacteria ◽  
Structural Variants ◽  
Quorum Sensing Inhibitors ◽  
Pharmaceutical Industries

The emergence of multidrug-resistant bacteria stimulates the search for new substitutes to traditional antimicrobial agents, especially molecules with antivirulence properties, such as those that interfere with quorum sensing (QS). This study aimed to evaluate the potential of phenolic compounds for QS inhibition in a QS biosensor strain (Chromobacterium violaceum) and three foodborne bacterial species (Aeromonas hydrophila, Salmonella enterica serovar Montevideo, and Serratia marcescens). Initially, an in silico molecular docking study was performed to select the compounds with the greatest potential for QS inhibition, using structural variants of the CviR QS regulator of C. violaceum as target. Curcumin, capsaicin, resveratrol, gallic acid, and phloridizin presented good affinity to at least four CviR structural variants. These phenolic compounds were tested for antimicrobial activity, inhibition of biofilm formation, and anti-QS activity. The antimicrobial activity when combined with kanamycin was also assessed. Curcumin, capsaicin, and resveratrol inhibited up to 50% of violacein production by C. violaceum. Biofilm formation was inhibited by resveratrol up to 80% in A. hydrophila, by capsaicin and curcumin up to 40% in S. Montevideo and by resveratrol and capsaicin up to 60% in S. marcescens. Curcumin completely inhibited swarming motility in S. marcescens. Additionally, curcumin and resveratrol increased the sensitivity of the tested bacteria to kanamycin. These results indicate that curcumin and resveratrol at concentrations as low as 6μM are potential quorum sensing inhibitors besides having antimicrobial properties at higher concentrations, encouraging applications in the food and pharmaceutical industries.

Substituted 6,7-dimethoxy-5-oxo-2,3,5,9b-tetrahydrothiazolo[2,3-a]isoindole- 3-1,1-dioxide Derivatives with Antimicrobial Activity and Docking Assisted Prediction of the Mechanism of their Antibacterial and Antifungal Properties

2020 ◽  
Vol 20 (29) ◽  
pp. 2681-2691
Author(s):  
Athina Geronikaki ◽  
Victor Kartsev ◽  
Phaedra Eleftheriou ◽  
Anthi Petrou ◽  
Jasmina Glamočlija ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antifungal Activity ◽  
Drug Targets ◽  
Bacterial Species ◽  
Pharmaceutical Research ◽  
Docking Studies ◽  
Fungal Species ◽  
Docking Analysis ◽  
E Coli ◽  
Antibacterial And Antifungal

Background: Although a great number of the targets of antimicrobial therapy have been achieved, it remains among the first fields of pharmaceutical research, mainly because of the development of resistant strains. Docking analysis may be an important tool in the research for the development of more effective agents against specific drug targets or multi-target agents 1-3. Methods: In the present study, based on docking analysis, ten tetrahydrothiazolo[2,3-a]isoindole derivatives were chosen for the evaluation of the antimicrobial activity. Results: All compounds showed antibacterial activity against eight Gram-positive and Gram-negative bacterial species being, in some cases, more potent than ampicillin and streptomycin against all species. The most sensitive bacteria appeared to be S. aureus and En. Cloacae, while M. flavus, E. coli and P. aeruginosa were the most resistant ones. The compounds were also tested for their antifungal activity against eight fungal species. All compounds exhibited good antifungal activity better than reference drugs bifonazole (1.4 – 41 folds) and ketoconazole (1.1 – 406 folds) against all fungal species. In order to elucidate the mechanism of action, docking studies on different antimicrobial targets were performed. Conclusion: According to docking analysis, the antifungal activity can be explained by the inhibition of the CYP51 enzyme for most compounds with a better correlation of the results obtained for the P.v.c. strain (linear regression between estimated binding Energy and log(1/MIC) with R 2 =0.867 and p=0.000091 or R 2 = 0.924, p= 0.000036, when compound 3 is excluded.

Co-modification of a lignocellulosic biomass by maleic anhydride and ferric hydroxide for high-efficient biosorption of methylene blue

2021 ◽  
Author(s):  
Youcheng Gao ◽  
Jun Zeng ◽  
Siming Zhu ◽  
Qiang Liu
Keyword(s):  
Methylene Blue ◽  
Maleic Anhydride ◽  
Sugar Beet ◽  
Lignocellulosic Biomass ◽  
Ferric Hydroxide ◽  
Sugar Beet Pulp ◽  
Microwave Assisted ◽  
High Efficient ◽  
Beet Pulp ◽  
Ft Ir

Herein, a novel biosorbent originated from sugar beet pulp (SBP) was synthesized by microwave-assisted esterification with maleic anhydride (MA) and further decoration with ferric hydroxide. Characterized methods including FT-IR, SEM,...

scholarly journals Bystander Phage Therapy: Inducing Host-Associated Bacteria to Produce Antimicrobial Toxins against the Pathogen Using Phages

Antibiotics ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 105 ◽  
Author(s):  
T. Brady ◽  
Christopher Fajardo ◽  
Bryan Merrill ◽  
Jared Hilton ◽  
Kiel Graves ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Causative Agent ◽  
Recovery Rate ◽  
Phage Therapy ◽  
Bacterial Species ◽  
American Foulbrood ◽  
Associated Bacteria ◽  
Field Isolates ◽  
Brevibacillus Laterosporus ◽  
Bystander Killing

Brevibacillus laterosporus is often present in beehives, including presence in hives infected with the causative agent of American Foulbrood (AFB), Paenibacillus larvae. In this work, 12 B. laterosporus bacteriophages induced bactericidal products in their host. Results demonstrate that P. larvae is susceptible to antimicrobials induced from field isolates of the bystander, B. laterosporus. Bystander antimicrobial activity was specific against the pathogen and not other bacterial species, indicating that the production was likely due to natural competition between the two bacteria. Three B. laterosporus phages were combined in a cocktail to treat AFB. Healthy hives treated with B. laterosporus phages experienced no difference in brood generation compared to control hives over 8 weeks. Phage presence in bee larvae after treatment rose to 60.8 ± 3.6% and dropped to 0 ± 0.8% after 72 h. In infected hives the recovery rate was 75% when treated, however AFB spores were not susceptible to the antimicrobials as evidenced by recurrence of AFB. We posit that the effectiveness of this treatment is due to the production of the bactericidal products of B. laterosporus when infected with phages resulting in bystander-killing of P. larvae. Bystander phage therapy may provide a new avenue for antibacterial production and treatment of disease.

scholarly journals Polymeric Nanoparticles Active against Dual-Species Bacterial Biofilms

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4958
Author(s):  
Jessa Marie V. Makabenta ◽  
Jungmi Park ◽  
Cheng-Hsuan Li ◽  
Aritra Nath Chattopadhyay ◽  
Ahmed Nabawy ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Laser Scanning ◽  
Polymeric Nanoparticles ◽  
Bacterial Species ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Bacterial Biofilms ◽  
Global Public Health ◽  
Bacterial Strains

Biofilm infections are a global public health threat, necessitating new treatment strategies. Biofilm formation also contributes to the development and spread of multidrug-resistant (MDR) bacterial strains. Biofilm-associated chronic infections typically involve colonization by more than one bacterial species. The co-existence of multiple species of bacteria in biofilms exacerbates therapeutic challenges and can render traditional antibiotics ineffective. Polymeric nanoparticles offer alternative antimicrobial approaches to antibiotics, owing to their tunable physico-chemical properties. Here, we report the efficacy of poly(oxanorborneneimide) (PONI)-based antimicrobial polymeric nanoparticles (PNPs) against multi-species bacterial biofilms. PNPs showed good dual-species biofilm penetration profiles as confirmed by confocal laser scanning microscopy. Broad-spectrum antimicrobial activity was observed, with reduction in both bacterial viability and overall biofilm mass. Further, PNPs displayed minimal fibroblast toxicity and high antimicrobial activity in an in vitro co-culture model comprising fibroblast cells and dual-species biofilms of Escherichia coli and Pseudomonas aeruginosa. This study highlights a potential clinical application of the presented polymeric platform.

scholarly journals Evaluation of Antibacterial Effects of Fissure Sealants Containing Chitosan Nanoparticles

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Sedighe Sadat Hashemi kamangar ◽  
Houtan Zareian ◽  
Abbas Bahador ◽  
Maryam Pourhajibagher ◽  
Zahra Bashareh ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Effect ◽  
Bacterial Species ◽  
Chitosan Nanoparticles ◽  
Control Group ◽  
Fissure Sealants ◽  
Biofilm Inhibition ◽  
Biofilm Growth ◽  
Fissure Sealant ◽  
Significant Difference

Objectives. The present study evaluated the antimicrobial effects of fissure sealants containing chitosan nanoparticles. Materials and Methods. Antibacterial effect of Master Dent fissure sealant alone and after incorporating chitosan nanoparticles was evaluated on Streptococcus mutans, sanguis, and Lactobacillus acidophilus. Biofilm growth was evaluated by determining colony counts. Antimicrobial effect was determined on days 3, 15, and 30 by counting microbial colonies using eluted components test. One-way ANOVA, Tukey HSD tests, t test, and two-way ANOVA were used for statistical analyses (α = 0.05). Results. Biofilm inhibition test showed that fissure sealant containing 1 wt.% chitosan decreased colony counts significantly ( P < 0.05 ). Eluted components test with S. mutans and sanguis showed significant decrease in colony counts during the first 15 days in chitosan containing group; however, from day 30, antimicrobial activity decreased noticeably, with no significant difference from control group ( P > 0.05 ). Antimicrobial activity against L. acidophilus was maintained in chitosan group up to 30 days, and decrease in colony counts was significant ( P < 0.05 ). Conclusion. According to the results of this study, incorporation of 1 wt.% chitosan into fissure sealant induced an antimicrobial activity. Antibacterial effect on L. acidophilus persisted for longer time (30 days) compared to the two other bacterial species (15 days).

Sign in / Sign up

Export Citation Format

Share Document