Nanoparticles

2014 ◽  
pp. 1071-1089
Author(s):  
Bakhtiyor Rasulev ◽  
Danuta Leszczynska ◽  
Jerzy Leszczynski
Keyword(s):  
Biological Activity ◽  
Quantum Chemical ◽  
Chemical Properties ◽  
Natural Sciences ◽  
Modern Life ◽  
Quantum Chemical Methods ◽  
Physico Chemical ◽  
Structure Of Nanomaterials ◽  
The Subject ◽  
Complicated Task

Nanomaterials are becoming an important component of the modern life and have been the subject of increasing number of investigations involving various areas of natural sciences and technology. However, theoretical modeling of physicochemical and biological activity of these species is still very scarce. The prediction of the properties and activities of ‘classical’ substances via correlating with molecular descriptors is a well known procedure, i.e. QSAR. In spite of this, the application of QSAR for the nanomaterials is a very complicated task, because of “non-classical” structure of nanomaterials. Here, the authors show that an application of the QSAR methods for nanomaterials is nevertheless possible and can be useful in predicting their various properties and activities (toxicity). In the chapter briefly explained how the physico-chemical properties can be predicted for nanomaterials. Furthermore, it was also demonstrated how the biological activity, particularly toxicity, can be modeled and predicted for the series of nanoparticles, by applying the quantum-chemical methods in combination with the nano-QSAR.

Nanoparticles

2011 ◽  
pp. 92-110
Author(s):  
Bakhtiyor Rasulev ◽  
Danuta Leszczynska ◽  
Jerzy Leszczynski
Keyword(s):  
Biological Activity ◽  
Quantum Chemical ◽  
Chemical Properties ◽  
Chemical Methods ◽  
Quantum Chemical Methods ◽  
Physico Chemical

Here, the authors show that an application of the QSAR methods for nanomaterials is nevertheless possible and can be useful in predicting their various properties and activities (toxicity). In the chapter briefly explained how the physico-chemical properties can be predicted for nanomaterials. Furthermore, it was also demonstrated how the biological activity, particularly toxicity, can be modeled and predicted for the series of nanoparticles, by applying the quantum-chemical methods in combination with the nano-QSAR.

scholarly journals Silver Nanoparticles Stabilized with Phosphorus-Containing Heterocyclic Surfactants: Synthesis, Physico-Chemical Properties, and Biological Activity Determination

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1883
Author(s):  
Martin Pisárčik ◽  
Miloš Lukáč ◽  
Josef Jampílek ◽  
František Bilka ◽  
Andrea Bilková ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Biological Activity ◽  
Zeta Potential ◽  
Chain Length ◽  
Alkyl Chain ◽  
Chemical Properties ◽  
Alkyl Chain Length ◽  
Microbial Pathogens ◽  
Physico Chemical ◽  
Phosphorus Containing

Phosphorus-containing heterocyclic cationic surfactants alkyldimethylphenylphospholium bromides with the alkyl chain length 14 to 18 carbon atoms were used for the stabilization of silver nanodispersions. Zeta potential of silver nanodispersions ranges from +35 to +70 mV, which indicates the formation of stable silver nanoparticles (AgNPs). Long-chain heptadecyl and octadecyl homologs of the surfactants series provided the most intensive stabilizing effect to AgNPs, resulting in high positive zeta potential values and smaller diameter of AgNPs in the range 50–60 nm. A comparison with non-heterocyclic alkyltrimethylphosphonium surfactants of the same alkyl chain length showed better stability and more positive zeta potential values for silver nanodispersions stabilized with heterocyclic phospholium surfactants. Investigations of biological activity of phospholium-capped AgNPs are represented by the studies of antimicrobial activity and cytotoxicity. While cytotoxicity results revealed an increased level of HepG2 cell growth inhibition as compared with the cytotoxicity level of silver-free surfactant solutions, no enhanced antimicrobial action of phospholium-capped AgNPs against microbial pathogens was observed. The comparison of cytotoxicity of AgNPs stabilized with various non-heterocyclic ammonium and phosphonium surfactants shows that AgNPs capped with heterocyclic alkyldimethylphenylphospholium and non-heterocyclic triphenyl-substituted phosphonium surfactants have the highest cytotoxicity among silver nanodispersions stabilized by the series of ammonium and phosphonium surfactants.

scholarly journals Neurokinin Receptor Inhibitors: Fermentation, Isolation, Physico-chemical Properties, Structure and Biological Activity.

1997 ◽  
Vol 50 (12) ◽  
pp. 983-991 ◽  
Author(s):  
VINOD R. HEGDE ◽  
PING DAI ◽  
MIN CHU ◽  
MAHESH PATEL ◽  
ROBERT BRYANT ◽  
...  
Keyword(s):  
Biological Activity ◽  
Chemical Properties ◽  
Neurokinin Receptor ◽  
Physico Chemical

scholarly journals FR112123, a new oligopeptide antibiotic from Streptomyces viridochromogenes. Taxonomy, fermentation, isolation, physico-chemical properties, structure and biological activity.

1990 ◽  
Vol 43 (5) ◽  
pp. 449-455 ◽  
Author(s):  
AKIHIKO FUJIE ◽  
TOSHIRO IWAMOTO ◽  
NOBUHARU SHIGEMATSU ◽  
MASAMI EZAKI ◽  
MOTOHIRO HINO ◽  
...  
Keyword(s):  
Biological Activity ◽  
Chemical Properties ◽  
Physico Chemical

scholarly journals Novel Fungal Metabolites as Cell Wall Active Antifungals. Fermentation, Isolation, Physico-chemical Properties, Structure and Biological Activity.

2001 ◽  
Vol 54 (1) ◽  
pp. 74-83 ◽  
Author(s):  
VINOD R. HEGDE ◽  
JACK SILVER ◽  
MAHESH PATEL ◽  
VINCENT P. GULLO ◽  
RAYMOND YARBOROUGH ◽  
...  
Keyword(s):  
Cell Wall ◽  
Biological Activity ◽  
Chemical Properties ◽  
Fungal Metabolites ◽  
Physico Chemical

scholarly journals New antiviral antibiotics, cycloviracins B1 and B2. I. Production, isolation, physico-chemical properties and biological activity.

1992 ◽  
Vol 45 (9) ◽  
pp. 1467-1471 ◽  
Author(s):  
MLTSUAKI TSUNAKAWA ◽  
NOBUJIRO KOMIYAMA ◽  
OSAMU TENMYO ◽  
KOJI TOMITA ◽  
KIMIO KAWANO ◽  
...  
Keyword(s):  
Biological Activity ◽  
Chemical Properties ◽  
Physico Chemical

scholarly journals New QSAR and Solvatochromic Estimation of Molecular Parameters of Chlortetracycline

2020 ◽  
Vol 71 (2) ◽  
pp. 121-127
Author(s):  
Antonina Gritco-Todirascu ◽  
Dorina Emilia Creanga ◽  
Liliana Mihaela Ivan ◽  
Dana Ortansa Dorohoi ◽  
Anamaria Ciubara
Keyword(s):  
Biological Activity ◽  
Chemical Properties ◽  
Basic Structure ◽  
Variation Method ◽  
Absorption Bands ◽  
Spectral Shifts ◽  
Physico Chemical ◽  
Excited State Dipole Moment ◽  
Qsar Parameters

The present paper is focused on determination of the main parameters of Chlortetracycline. Chlortetracycline belongs to one of the most used family of antibiotics worldwide, Tetracyclines. Because of the large spectrum of infections which can be treated with this category of antibiotics there are attempts to find new derivatives from this class. The compounds derived from the same basic structure exhibit same chemical properties, that is why knowing in detail the main physico-chemical properties of Chlortetracycline could be a real help in synthesize new efficient derivatives. In order to evaluate the reactivity and biological activity HyperChem was used to establish the optimized structure, the electro-optical, the energetic and QSAR parameters. The solvatochromic methods allowed determining the intermolecular interactions types and their contribution to the spectral shifts of measured electronic absorption bands. Based on computational and solvatochromic results, the excited state dipole moment of Chlortetracycline was established by variation method.

scholarly journals The use of UniProtKB/BIOPEP for the analysis of oat globulin physicochemical parameters and bioactivity

2018 ◽  
Vol 36 (No. 2) ◽  
pp. 119-125 ◽  
Author(s):  
Szerszunowicz Iwona ◽  
Nałęcz Dorota
Keyword(s):  
Biological Activity ◽  
Ace Inhibitors ◽  
Physicochemical Parameters ◽  
Chemical Properties ◽  
Signal Peptides ◽  
Optimum Conditions ◽  
Physico Chemical ◽  
Functional Peptides ◽  
Chymotrypsin A ◽  
11S Globulins

The physico-chemical properties of oat proteins (globulins) were determined and an analysis was done whether products of in silico proteolysis contain mono- and multi-functional peptides with various biological activity. The MW(s), calculated by the ProtParam program, for precursors of 12S and 11S globulins and proteins without signal peptides were in the range of 50.78–61.86 kDa. The pH at which the solubility of the proteins under analysis was the lowest ranged from 7.29 to 9.44. A simulation of proteolysis with three enzymes (pepsin, trypsin, and chymotrypsin A) in the optimum conditions of the enzyme action can produce 6–8 bi-functional, 5–10 mono-functional biopeptides from oat globulins (12S, 11S globulins), and one tri-functional biopeptide (VY). The mono-functional biopeptides exhibited the activity of DPPIV inhibitors or ACE inhibitors, and the multi-functional biopeptides can exhibit the activity of inhibitors of both enzymes (DPPIV and ACE). Sensory peptides accounted for 43% of all the released mono- and multi-functional biopeptides.

Redox Biotransformation and Delivery of Anthracycline Anticancer Antibiotics: How Interpretable Structure-activity Relationships of Lethality Using Electrophilicity and the London Formula for Dispersion Interaction Work

2018 ◽  
Vol 18 (6) ◽  
pp. 600-607
Author(s):  
Siu-Kwong Pang
Keyword(s):  
Biological Activity ◽  
Drug Metabolism ◽  
Quantum Chemical ◽  
Molecular Descriptors ◽  
Molecular Level ◽  
Dispersion Interaction ◽  
Chemical Methods ◽  
Structure Activity ◽  
Quantum Chemical Methods ◽  
Metabolism Study

Background: Quantum chemical methods and molecular mechanics approaches face a lot of challenges in drug metabolism study because of either insufficient accuracy, huge computational cost, or lack of clear molecular level pictures for building computational models. Low-cost QSAR methods can often be carried out, even though molecular level pictures are not well defined; however, they show difficulty in identifying the mechanisms of drug metabolism and delineating the effects of chemical structures on drug toxicity because a certain amount of molecular descriptors are difficult to be interpreted. Objective: In order to make a breakthrough of QSAR, mechanistically interpretable molecular descriptors were used to correlate with biological activity to establish structure-activity plots. The biological activity is the lethality of anthracycline anticancer antibiotics denoted as log LD50. The mechanistically interpretable molecular descriptors include electrophilicity and the mathematical function in the London formula for dispersion interaction. Method: The descriptors were calculated using quantum chemical methods. Results: The plots for electrophilicity, which is interpreted as redox reactivity of anthracyclines, can describe oxidative degradation for detoxification and reductive bioactivation for toxicity induction. The plots for the dispersion interaction function, which represents the attraction between anthracyclines and biomolecules, can describe efflux from and influx into the target cells of toxicity. The plots can also identify three structural scaffolds of anthracyclines that have different metabolic pathways, resulting in their different toxicity behavior. Conclusion: This structure-dependent toxicity behavior revealed in the plots can provide perspectives on drug design and drug metabolism study.

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