scholarly journals “Smart” Triiodide Compounds: Does Halogen Bonding Influence Antimicrobial Activities?

Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 182 ◽  
Author(s):  
Edis ◽  
Haj Bloukh ◽  
Abu Sara ◽  
Bhakhoa ◽  
Rhyman ◽  
...  

Antimicrobial agents containing symmetrical triiodides complexes with halogen bonding may release free iodine molecules in a controlled manner. This happens due to interactions with the plasma membrane of microorganisms which lead to changes in the structure of the triiodide anion. To verify this hypothesis, the triiodide complex [Na(12-crown-4)2]I3 was prepared by an optimized one-pot synthesis and tested against 18 clinical isolates, 10 reference strains of pathogens and five antibiotics. The antimicrobial activities of this symmetrical triiodide complex were determined by zone of inhibition plate studies through disc- and agar-well-diffusion methods. The triiodide complex proved to be a broad spectrum microbicidal agent. The biological activities were related to the calculated partition coefficient (octanol/water). The microstructural analysis of SEM and EDS undermined the purity of the triiodide complex. The anionic structure consists of isolated, symmetrical triiodide anions [I-I-I]- with halogen bonding. Computational methods were used to calculate the energy required to release iodine from [I-I-I]- and [I-I···I]-. The halogen bonding in the triiodide ion reduces the antibacterial activities in comparison to the inhibitory actions of pure iodine but increases the long term stability of [Na(12-crown-4)2]I3.

Biomimetics ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 45 ◽  
Author(s):  
Zehra Edis ◽  
Samir Haj Bloukh

Antibiotic resistance is an eminent threat for the survival of mankind. Nosocomial infections caused by multidrug resistant microorganisms are a reason for morbidity and mortality worldwide. Plant-based antimicrobial agents are based on synergistic mechanisms which prevent resistance and have been used for centuries against ailments. We suggest the use of cost-effective, eco-friendly Aloe Vera Barbadensis Miller (AV)-iodine biomaterials as a new generation of antimicrobial agents. In a facile, one-pot synthesis, we encapsulated fresh AV gel with polyvinylpyrrolidone (PVP) as a stabilizing agent and incorporated iodine moieties in the form of iodine (I2) and sodium iodide (NaI) into the polymer matrix. Ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), x-ray diffraction (XRD), microstructural analysis by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) verified the composition of AV-PVP-I2, AV-PVP-I2-NaI. AV, AV-PVP, AV-PVP-I2, AV-PVP-I2-NaI, and AV-PVP-NaI were tested in-vitro by disc diffusion assay and dip-coated on polyglycolic acid (PGA) sutures against ten microbial reference strains. All the tested pathogens were more susceptible towards AV-PVP-I2 due to the inclusion of “smart” triiodides with halogen bonding in vitro and on dip-coated sutures. The biocomplexes AV-PVP-I2, AV-PVP-I2-NaI showed remarkable antimicrobial properties. “Smart” biohybrids with triiodide inclusions have excellent antifungal and promising antimicrobial activities, with potential use against surgical site infections (SSI) and as disinfecting agents.


1999 ◽  
Vol 43 (3) ◽  
pp. 582-588 ◽  
Author(s):  
D. E. Mahony ◽  
S. Lim-Morrison ◽  
L. Bryden ◽  
G. Faulkner ◽  
P. S. Hoffman ◽  
...  

Clostridium difficile is a major nosocomial pathogen responsible for pseudomembranous colitis and many cases of antibiotic-associated diarrhea. Because of potential relapse of disease with current antimicrobial therapy protocols, there is a need for additional and/or alternative antimicrobial agents for the treatment of disease caused by C. difficile. We have synthesized a systematic series of 14 structurally simple bismuth compounds and assessed their biological activities against C. difficile and four other gastrointestinal species, includingHelicobacter pylori. Here, we report on the activities of six compounds that exhibit antibacterial activities againstC. difficile, and some of the compounds have MICs of less than 1 μg/ml. Also tested, for comparison, were the activities of bismuth subcitrate and ranitidine bismuth citrate obtained from commercial sources. C. difficile andH. pylori were more sensitive both to the synthetic bismuth compounds and to the commercial products than were Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis, and the last three species were markedly resistant to the commercial bismuth salts. Testing with human foreskin fibroblast cells revealed that some of the synthetic compounds were more cytotoxic than others. Killing curves for C. difficile treated with the more active compounds revealed rapid death, and electron microscopy showed that the bismuth of these compounds was rapidly incorporated by C. difficile. Energy dispersive spectroscopy X-ray microanalysis of C. difficile cells containing electron-dense material confirmed the presence of internalized bismuth. Internalized bismuth was not observed inC. difficile treated with synthetic bismuth compounds that lacked antimicrobial activity, which suggests that the uptake of the metal is required for killing activity. The nature of the carrier would seem to determine whether bismuth is transported into susceptible bacteria like C. difficile.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Mohamed A. Abdelgawad ◽  
Mohammad M. Al-Sanea ◽  
Mohamed A. Zaki ◽  
Enas I. A. Mohamed ◽  
Shabana I. Khan ◽  
...  

Background. Benzoxazole derivatives have different biological activities. In pursuit of designing novel chemical entities with antiprotozoal and antimicrobial activities, benzoxazolyl aniline was utilized as a privileged scaffold of a series of (3-benzoxazole-2-yl) phenylamine derivatives, 3-benzoxazoloyl acetamide, and butyramide derivatives. Methods. These novel analogs were synthesized in straightforward simple chemistry without any quantitative chromatographic separations in reasonable yields. The biological evaluation of all target compounds as potential antimalarial, antileishmanial, antitrypanosomal, and antimicrobial agents was performed by various well-established cell-based methods. Results. Compounds 6d and 5a showed promising biological screening data. The amidation of 3-benzoxazolyl aniline 1 with the chloroacetyl functional group resulted in a good antimalarial activity and showed moderate inhibitory activities against leishmanial and trypanosomal spp. Moreover, chloroacetyl functionalization of benzoxazolyl aniline serves as a good early goal for constructing and synthesizing new antimicrobial and antiprotozoal agents. The molecular docking study rationalizes the relative inhibitory activity of compound 5a as an antimalarial agent with the deregulation of PfPNP activity which has emerged as a major mechanism of these targets.


Author(s):  
Sudip Kumar Mandal

 Objective: The wide variety of biological activities of different indane derivatives makes them an interesting moiety in the field of medicinal chemistry. The objective of the study was to identify and develop novel antimicrobial agents from indanyl analogs.Methods: Recently synthesized indanyl analogs (4a-c and 5a-o) were examined against various pathogenic microorganisms (Gram-positive and Gram-negative bacteria and fungi) using serial dilution method. These analogs were found to possess antibacterial and antifungal activities with minimum inhibitory concentration values ranging between 1.56 and 100 μg/mL.Results: The results revealed that the entire compounds showed mild-to-moderate antibacterial activities and moderate-to-excellent antifungal activities against the pathogenic microorganisms as compared to the standard drugs ciprofloxacin and fluconazole, respectively. Compounds 4a, 5a, 5b, 5d, 5e, 5i, and 5j exhibited antifungal activities superior to the reference drug.Conclusion: Based on the structure-activity relationship, it can conclude that the indan-3-oxo-1-acetic acid moiety is essential for the activities and lipophilic alkoxy substituents on indane ring have enhanced the biological activity. Further, structure-activity relationship studies of the compounds 4a, 5a, and 5b are needful to find the new lead as antimicrobial agent.


Author(s):  
KOSARAJU LAHARI ◽  
RAJA SUNDARARAJAN

Objective: Isatins have emerged as antimicrobial agents due to their broad spectrum of in vitro and in vivo antimicrobial activities. In addition, thiazolidinone also reported to possess various biological activities particularly antimicrobial activity. Due to the importance, we planned to synthesize compounds with isatin functionality coupled with thiazolidinone as possible antitubercular and antimicrobial agents which could furnish better therapeutic results. Methods: In vitro Mycobacterium tuberculosis method and agar streak dilution test are used to estimate antitubercular and antimicrobial potency of title analogs, respectively. Minimum inhibitory concentration of entire title compounds was determined against all tested microorganism such as M. tuberculosis, four Gram-positive, three Gram-negative bacteria, and two fungi. Results: A series of new thiazolidinone substituted Schiff and Mannich bases of 5-nitroisatins were designed and synthesized by a multistep synthesis from isatin. Structures of synthesized compounds are characterized using Fourier-transform infrared, proton nuclear magnetic resonance, mass spectroscopy, and bases of elemental analysis. Mild to good antitubercular and antimicrobial activity was showed by synthesized 5-nitroisatin analogs. The relationship between the biological activity and the functional group variation of the tested compounds was discussed. Conclusion: 3-(4-(3-(4-Aminophenyl)-4-oxothiazolidin-2-yl)phenylimino)-1-((dimethyl amino)methyl)-5-nitroindolin-2-one 6 and 3-(4-(3- (2-aminophenyl)-4-oxothiazolidin-2-yl)phenylimino)-1-((dimethylamino)methyl)-5-nitroindolin-2-one 13 were found to be the most potent compounds of this series which might be extended as a novel class of antimicrobial agents.


2016 ◽  
Vol 6 (12) ◽  
pp. 4616-4631 ◽  
Author(s):  
K. Jabbour ◽  
N. El Hassan ◽  
A. Davidson ◽  
S. Casale ◽  
P. Massiani

Direct “one-pot” synthesis is highly efficient to obtain performing mesoporous Ni–Al2O3catalysts able to resist deactivation by sintering and coke deposition during CH4reforming by CO2and H2O to produce “metgas”.


2017 ◽  
Vol 13 (1) ◽  
pp. 49-55
Author(s):  
Sevil Albayrak ◽  
Ahmet Aksoy ◽  
Abit Yasar ◽  
Lutfiye Yurtseven ◽  
Umit Budak

Objectives: In vitro biological activities of methanolic extracts of five Turanecio species have been studied. Materials and Methods: The phenolic compositions of the extracts were evaluated by the Folin- Ciocalteu assay and by HPLC analysis. Antioxidant activities were determined with two in vitro assays namely, DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging assay and phosphomolybdenum assay. The antimicrobial activities of the extracts were evaluated against 13 microorganisms. Results: T. hypochionaeus var. hypochionaeus was showed the highest DPPH inhibition with 88.84% at 100 μg·mL-1. All of the extracts were exerted high total antioxidant activities 128.00- 243.13 mg AAE g-1) and seem to be a promising source of natural antioxidants. The phenolic contents in the extracts varied from 26.17 to 60.99 mg·g-1 as gallic acid equivalent. Chlorogenic acid, caffeic acid and p- coumaric acid were the predominant constituents. The methanolic extracts revealed promising antibacterial activities against most bacteria. No activity was recorded against yeasts tested. Conclusion: The polyphenolic constituents appear to be responsible, at least in part, for the extract’s activities. The present study confirms that tested Turanecio species contains significant source of phenolics have antioxidant and antimicrobial activities and may have therapeutic potential.


Author(s):  
Praveen Kumar Sharma ◽  
Reena Makkar

ABSTRACTIn recent days, heterocycles and their derivatives have become strong reflection in medicinal research and pharmaceutical fields because of theirpractical pharmacological and biological activities. Organic compounds; mainly heterocyclic compounds are wealthy in natural world and containextra value because their structural subunits are established in many natural products such as enzymes, vitamins, antibiotics, acids, and hormones.Thiazine nucleuses found in compounds have variety of pharmacological activities such as antitumor, antimicrobial, antibacterial, antifungal, antiviral,and anti-inflammatory. This review spotlight on the substituted thiazines with possible antimicrobial activities that are at the present in development.Keywords: Antibacterial, Substituted thiazines, Antimicrobial agents.


2021 ◽  
Author(s):  
Venkataramanan Mahalingam ◽  
Gouri Tudu ◽  
Sourav Ghosh ◽  
Sagar Ganguli ◽  
Murthy Koppsetti ◽  
...  

Sustainable electrocatalytic water splitting stipulates development of cheap, efficient and stable electrocatalysts to promote comparatively sluggish oxygen evolution reaction. We have synthesized iron incorporated pure phase α-nickel hydroxide, Ni0.8Fe0.2(OH)2 electrocatalyst...


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1568
Author(s):  
Arinao Murei ◽  
Karen Pillay ◽  
Patrick Govender ◽  
Ntevheleni Thovhogi ◽  
Wilson M. Gitari ◽  
...  

In the present study, silver nanoparticles (AgNPs) were synthesized using both the chemical and biological methods and conjugated with Pyrenacantha grandiflora extracts. These were then characterized and evaluated for antimicrobial activities against multi-drug resistant pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumonia, and Escherichia coli. Nanoparticles were analyzed with UV-visible spectrophotometer, transmission electron microscopy (TEM), and energy dispersive X-ray analysis (EDX). Silver nanoparticles, P. grandiflora extracts, and the conjugates were also analyzed with Fourier transform infrared spectroscopy (FTIR). As a result, quasi-sphere-shaped AgNPs with sizes ranging from 5 to 33 nm and spherically shaped AgNPs with sizes ranging from 3 to 25 nm were formed from chemical and biological synthesis, respectively. A well diffusion assay showed that the activity of silver nanoparticles was most improved with acetone extract against all tested bacteria with diameters in the range of 19–24 mm. The lowest MIC value of 0.0063 mg/mL against MRSA was observed when biologically synthesized AgNPs were conjugated with acetone and water extracts. Chemically synthesized silver nanoparticles showed the lowest MIC value of 0.0063 mg/mL against E. coli when conjugated with acetone and methanol extracts. This study indicates that silver nanoparticles conjugated with P. gandiflora tubers extracts exhibit strong antibacterial activities against multi-drug resistant bacterial pathogens. Therefore, biosynthesized conjugates could be utilized as antimicrobial agents for effective disease management due to the synergistic antibacterial activity that was observed.


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