scholarly journals New Relevant Descriptor of Linear QNAR Models for Toxicity Assessment of Silver Nanoparticles

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1459
Author(s):  
Alexey Kudrinskiy ◽  
Pavel Zherebin ◽  
Alexander Gusev ◽  
Olga Shapoval ◽  
Jaeho Pyee ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Biological Activity ◽  
Colloidal Stability ◽  
Chemical Nature ◽  
Equilibrium Concentration ◽  
Toxicity Assessment ◽  
Yeast Cells ◽  
Wide Range ◽  
Silver Nps ◽  
Living Organisms

The use of silver nanoparticles (NPs) in medical, industrial and agricultural fields is becoming more widespread every year. This leads to an increasing number of experimental toxicological and microbiological studies of silver NPs aimed at establishing the risk–benefit ratio for their application. The following key parameters affecting the biological activity of silver dispersions are traditionally taken into consideration: mean diameter of NPs, surface potential of NPs and equilibrium concentration of Ag+. These characteristics are mainly predetermined by the chemical nature of the capping agent used for stabilization. However, the extent to which they influence the biological activity and the toxicity of silver NPs varies greatly. In this work, dispersions of silver NPs stabilized with a wide array of substances of different chemical nature were used for quantitative evaluation of whether the various measurable properties of silver NPs fit as descriptors of linear QNAR (quantitative nanostructure–activity relationship) models for silver NP toxicity evaluation with respect to a model eukaryotic microorganism—Saccharomyces cerevisiae yeast cells. It was shown that among the factors that determine silver NP toxicity, the charge of particles, their colloidal stability and the ability to generate Ag+ ions carry more importance than the descriptors related to the particle size. A significant synergistic effect between the ζ-potential and the colloidal stability of silver NPs on their toxicity was also discovered. Following this, a new descriptor has been proposed for the integral characterization of the silver dispersion colloidal stability. According to the obtained data, it can be considered applicable for building QNAR models of higher efficacy. The validity testing of the proposed model for theoretical prediction of silver NP toxicity using a wide range of living organisms has shown that this new descriptor correlates with toxicity much better compared to most traditionally used descriptors. Consequently, it seems promising in terms of being used not only in situations involving the rather narrow array of the objects tested, but also for the construction of silver NP toxicity models with respect to other living organisms.

Identification of promising objects for the synthesis of thiosulphonate derivatives of benzoquinone and hydroquinone

2021 ◽  
Vol 4 (2) ◽  
pp. 47-53
Author(s):  
N. Y. Monka ◽  
◽  
N. E. Stadnytska ◽  
I. R. Buchkevych ◽  
K. O. Kaplia ◽  
...  
Keyword(s):  
Biological Activity ◽  
Biological Activities ◽  
Experimental Studies ◽  
New Drugs ◽  
Reduced Form ◽  
Free Form ◽  
Wide Range ◽  
On Line ◽  
Living Organisms ◽  
Derivatives Of

Benzoquinone and its reduced form hydroquinone belong to phenolic compounds and are found in living organisms in free form or in glycosides. They are active substances of some medicinal plants and have a pharmacological effect on the human body. Accordingly, their derivatives are important objects for chemical synthesis and development of new drugs. This article presents the findings of the structural design of substances with benzoquinone or hydroquinone fragment and sulfur-containing compound. By use of appropriate on-line programs a predictive screening of the biological activity and cytotoxicity of thiosulfonate derivatives of benzoquinone and hydroquinone has been conducted. It has been found that they have immense methodological potential to be synthesized by substances with a wide range of biological activities and a high value of probable activity, which substantiates the feasibility of conducting experimental studies on their biological activity, particularly anticancer.

scholarly journals Investigating the Role of Shape and Size of Gold Nanoparticles on Their Toxicities to Fungi

2018 ◽  
Author(s):  
Kangze Liu ◽  
Zhonglei He ◽  
Hugh J. Byrne ◽  
James Curtin ◽  
Furong Tian
Keyword(s):  
Gold Nanoparticles ◽  
Penicillium Chrysogenum ◽  
Survival Rates ◽  
Relative Survival ◽  
Toxicity Assessment ◽  
Mucor Hiemalis ◽  
Wide Range ◽  
Living Organisms ◽  
Shape And Size

The possibility of releasing gold nanoparticles (GNP) into the environment has been rapidly increasing with the wide spread and flourishing application of gold nanoparticles (GNPs) in a wide range of areas. Consequently, environmental effects of GNP, especially toxicities to living organisms have drawn great attention. However, their toxicological characteristics still remain unclear. Fungi, as the decomposers of the ecosystem, interact directly with the environment and critically control the overall health of the biosphere. Thus, their sensitivity to GNP toxicity is particularly important. The aim of this study was to evaluate the role of shape and size of GNPs on their toxicities to fungi, which could help reveal the ecotoxicity of GNPs. Aspergillus niger, Mucor hiemalis and Penicillium chrysogenum were chosen for toxicity assessment, and circular and star/flower-shaped GNPs sized from 0.7 nm to large aggregates of 400 nm have been synthesised. After mixed with GNPs and reacting agents of GNPs accordingly and incubated for 48 hours, the relative survival rates of each kind of fungus was calculated and compared. The results indicated that with similar sizes, star/flower-shaped GNPs are more toxic to fungi than circular-shaped GNPs; the toxicity of star/flower-shaped GNPs increases with smaller sizes. The results also showed that different species of fungus reacts differently to same GNPs, and Penicillium chrysogenum was relatively more sensitive under the exposure to GNPs.

scholarly journals Investigating the Role of Shape and Size of Gold Nanoparticles on Their Toxicities to Fungi

2018 ◽  
Author(s):  
Kangze Liu ◽  
Zhonglei He ◽  
Hugh J. Byrne ◽  
James F. Curtin ◽  
Furong Tian
Keyword(s):  
Gold Nanoparticles ◽  
Survival Rates ◽  
Toxicity Assessment ◽  
Fungal Species ◽  
Wide Spread ◽  
Mucor Hiemalis ◽  
Wide Range ◽  
Living Organisms ◽  
Shape And Size

The possibility of releasing gold nanoparticles (GNP) into the environment has been rapidly increasing with the wide spread and flourishing application of gold nanoparticles (GNPs) in a wide range of areas. Consequently, environmental effects of GNP, especially toxicities to living organisms have drawn great attention. However, their toxicological characteristics still remain unclear. Fungi, as the decomposers of the ecosystem, interact directly with the environment and critically control the overall health of the biosphere. Thus, their sensitivity to GNP toxicity is particularly important. The aim of this study was to evaluate the role of shape and size of GNPs on their toxicities to fungi, which could help reveal the ecotoxicity of GNPs. Aspergillus niger, Mucor hiemalis and Penicillium chrysogenum were chosen for toxicity assessment, and spherical and star/flower-shaped GNPs sized from 0.7 nm to large aggregates of 400 nm have been synthesised. After exposure to GNPs and their corresponding reaction agents and incubation for 48 hours, the survival rates of each kind of fungus was calculated and compared. The results indicated that fungal species was the major determinant of the variation of survival rates, whereby A. niger was most sensitive and M. himalis was least sensitive to GNP exposure. Additionally, larger and non-spherical GNPs had relatively stronger toxicities.

scholarly journals Coating-Dependent Effects of Silver Nanoparticles on Tobacco Seed Germination and Early Growth

2020 ◽  
Vol 21 (10) ◽  
pp. 3441 ◽  
Author(s):  
Renata Biba ◽  
Dajana Matić ◽  
Daniel Mark Lyons ◽  
Petra Peharec Štefanić ◽  
Petra Cvjetko ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Growth Parameters ◽  
Antimicrobial Properties ◽  
Chemical Properties ◽  
Early Growth ◽  
Consumer Products ◽  
Negative Effects ◽  
Wide Range ◽  
Living Organisms ◽  
The Stability

Silver nanoparticles (AgNPs) are used in a wide range of consumer products because of their excellent antimicrobial properties. AgNPs released into the environment are prone to transformations such as aggregation, oxidation, or dissolution so they are often stabilised by coatings that affect their physico-chemical properties and change their effect on living organisms. In this study we investigated the stability of polyvinylpyrrolidone (PVP) and cetyltrimethylammonium bromide (CTAB) coated AgNPs in an exposure medium, as well as their effect on tobacco germination and early growth. AgNP-CTAB was found to be more stable in the solid Murashige and Skoog (MS) medium compared to AgNP-PVP. The uptake and accumulation of silver in seedlings was equally efficient after exposure to both types of AgNPs. However, AgNP-PVP induced only mild toxicity on seedlings growth, while AgNP-CTAB caused severe negative effects on all parameters, even compared to AgNO3. Moreover, CTAB coating itself exerted negative effects on growth. Cysteine addition generally alleviated AgNP-PVP-induced negative effects, while it failed to improve germination and growth parameters after exposure to AgNP-CTAB. These results suggest that the toxic effects of AgNP-PVP are mainly a consequence of release of Ag+ ions, while phytotoxicity of AgNP-CTAB can rather be ascribed to surface coating itself.

Green and Simple Synthesis of Silver Nanoparticles by Aqueous Extract of Perovskia abrotanoides: Characterization, Optimization and Antimicrobial Activity

2020 ◽  
Vol 21 (11) ◽  
pp. 1129-1137 ◽  
Author(s):  
Somayeh Mirsadeghi ◽  
Masoumeh F. Koudehi ◽  
Hamid R. Rajabi ◽  
Seied M. Pourmortazavi
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Minimum Inhibitory Concentration ◽  
Plant Extract ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Extraction Temperature ◽  
Silver Particles ◽  
Silver Nps ◽  
Perovskia Abrotanoides

Background: Herein, we report the biosynthesis procedure to prepare silver nanoparticles as reduction and capping agents with the aqueous plant extract of Perovskia abrotanoides. Methods: The therapeutic application of silver nanoparticles entirely depends on the size and shape of the nanoparticles therefore, their control during the synthesis procedure is so important. The effects of synthesis factors, for example, silver ion concentration, the mass of plant extract, reaction time and extraction temperature, on the size of silver particles were considered and optimized. Several analytical methods were used for the characterization of silver NPs including FT-IR and UV–Vis spectrophotometer, XRD and SEM. Results: The results showed that the mean size of the silver particles was about 51 nm. Moreover, the antibacterial properties of biosynthesized silver NPs were investigated by the minimum inhibitory concentration, minimum bactericidal concentration, and Well-diffusion tests. The minimum inhibitory concentration/ minimum bactericidal concentration values of silver NPs and aqueous plant extract versus Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and Gram-negative bacteria (E. coli) were 3.03/0.00, 1.20/0.01, 3.06/0.00, 0.98/1.04, 1.00/0.05 and 1.30/0.03 (mg/mL), respectively. Conclusion: The antimicrobial activity study displayed that the synthesized silver nanoparticles by plant extract have better antimicrobial properties compared to aqueous plant extract of Perovskia abrotanoides.

Enzymes as a Reservoir of Host Defence Peptides

2020 ◽  
Vol 20 (14) ◽  
pp. 1310-1323
Author(s):  
Andrea Bosso ◽  
Antimo Di Maro ◽  
Valeria Cafaro ◽  
Alberto Di Donato ◽  
Eugenio Notomista ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Biological Activity ◽  
Internal Structure ◽  
Catalytic Properties ◽  
Cellular Responses ◽  
Host Defence ◽  
Present Review ◽  
Active Peptides ◽  
Wide Range

Host defence peptides (HDPs) are powerful modulators of cellular responses to various types of insults caused by pathogen agents. To date, a wide range of HDPs, from species of different kingdoms including bacteria, plant and animal with extreme diversity in structure and biological activity, have been described. Apart from a limited number of peptides ribosomally synthesized, a large number of promising and multifunctional HDPs have been identified within protein precursors, with properties not necessarily related to innate immunity, consolidating the fascinating hypothesis that proteins have a second or even multiple biological mission in the form of one or more bio-active peptides. Among these precursors, enzymes constitute certainly an interesting group, because most of them are mainly globular and characterized by a fine specific internal structure closely related to their catalytic properties and also because they are yet little considered as potential HDP releasing proteins. In this regard, the main aim of the present review is to describe a panel of HDPs, identified in all canonical classes of enzymes, and to provide a detailed description on hydrolases and their corresponding HDPs, as there seems to exist a striking link between these structurally sophisticated catalysts and their high content in cationic and amphipathic cryptic peptides.

Studies on the EC50 of Natural Monoterpenes as Fungal Inhibitors with Quantitative Structure-Activity Relationships (QSARs)

2020 ◽  
Vol 10 (1) ◽  
pp. 44-60
Author(s):  
Mohamed E.I. Badawy ◽  
Entsar I. Rabea ◽  
Samir A.M. Abdelgaleil
Keyword(s):  
Biological Activity ◽  
Plant Pathogens ◽  
Molecular Descriptors ◽  
Microbial Pathogens ◽  
Quantitative Structure ◽  
Qsar Study ◽  
Qsar Analysis ◽  
Pharmacophore Modelling ◽  
Structure Activity ◽  
Wide Range

Background:Monoterpenes are the main constituents of the essential oils obtained from plants. These natural products offered wide spectra of biological activity and extensively tested against microbial pathogens and other agricultural pests.Methods:Antifungal activity of 10 monoterpenes, including two hydrocarbons (camphene and (S)- limonene) and eight oxygenated hydrocarbons ((R)-camphor, (R)-carvone, (S)-fenchone, geraniol, (R)-linalool, (+)-menthol, menthone, and thymol), was determined against fungi of Alternaria alternata, Botrytis cinerea, Botryodiplodia theobromae, Fusarium graminearum, Phoma exigua, Phytophthora infestans, and Sclerotinia sclerotiorum by the mycelia radial growth technique. Subsequently, Quantitative Structure-Activity Relationship (QSAR) analysis using different molecular descriptors with multiple regression analysis based on systematic search and LOOCV technique was performed. Moreover, pharmacophore modelling was carried out using LigandScout software to evaluate the common features essential for the activity and the hypothetical geometries adopted by these ligands in their most active forms.Results:The results showed that the antifungal activities were high, but depended on the chemical structure and the type of microorganism. Thymol showed the highest effect against all fungi tested with respective EC50 in the range of 10-86 mg/L. The QSAR study proved that the molecular descriptors HBA, MR, Pz, tPSA, and Vp were correlated positively with the biological activity in all of the best models with a correlation coefficient (r) ≥ 0.98 and cross-validated values (Q2) ≥ 0.77.Conclusion:The results of this work offer the opportunity to choose monoterpenes with preferential antimicrobial activity against a wide range of plant pathogens.

scholarly journals Transformation of Contaminants of Emerging Concern (CECs) during UV-Catalyzed Processes Assisted by Chlorine

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1432
Author(s):  
Edyta Kudlek
Keyword(s):  
Hydrogen Peroxide ◽  
Water Samples ◽  
Water Environment ◽  
Toxicity Assessment ◽  
Contaminants Of Emerging Concern ◽  
Post Processing ◽  
Processing Water ◽  
Living Organisms ◽  
Trace Concentrations ◽  
By Products

Every compound that potentially can be harmful to the environment is called a Contaminant of Emerging Concern (CEC). Compounds classified as CECs may undergo different transformations, especially in the water environment. The intermediates formed in this way are considered to be toxic against living organisms even in trace concentrations. We attempted to identify the intermediates formed during single chlorination and UV-catalyzed processes supported by the action of chlorine and hydrogen peroxide or ozone of selected contaminants of emerging concern. The analysis of post-processing water samples containing benzocaine indicated the formation of seven compound intermediates, while ibuprofen, acridine and β-estradiol samples contained 5, 5, and 3 compound decomposition by-products, respectively. The number and also the concentration of the intermediates decreased with the time of UV irradiation. The toxicity assessment indicated that the UV-catalyzed processes lead to decreased toxicity nature of post-processed water solutions.

Synthesis of N ‐Acetylcysteine Conjugated Cholic Acid Stabilized Gold and Silver Nanoparticles: Evaluation of Their Catalytic Activity and Toxicity Assessment

2021 ◽  
Vol 6 (22) ◽  
pp. 5474-5487
Author(s):  
Nishanthi Ezhumalai ◽  
Manivannan Nanthagopal ◽  
Shanmugam Chandirasekar ◽  
Manikandan Elumalai ◽  
Mathivanan Narayanasamy ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Catalytic Activity ◽  
Cholic Acid ◽  
Toxicity Assessment ◽  
Gold And Silver Nanoparticles
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