Bioactive Nanoparticles The Complexation of Odorant Compounds with a-and b-Cyclodextrin

2008 ◽  
Vol 59 (2) ◽  
pp. 149-153 ◽  
Author(s):  
Adrian Rivis ◽  
Nicoleta Gabriela Hadaruga ◽  
Daniel Ioan Hadaruga ◽  
Teodor Trasca ◽  
Marioara Druga ◽  
...  
Keyword(s):  
Thermogravimetric Analysis ◽  
Environmental Factors ◽  
Water Solution ◽  
Point Of View ◽  
Water Soluble ◽  
Linalyl Acetate ◽  
Molecular Encapsulation ◽  
Hydrophobic Compounds ◽  
Bioactive Properties ◽  
Long Life

This paper presents the molecular encapsulation of some odorant compounds in a- or b-cyclodextrin. The molecular encapsulation of hydrophobic compounds in these natural cyclic oligosaccharides provides powders at nano scale with very good protection against degradative environmental factors (temperature, light, moisture, air/oxygen), controlled release of the bioactive compounds (long life bio-action), easy handling of powdery complexes (containing bioactive liquid compounds), higher water soluble bioactive specialties (containing hydrophobic biocompounds). From this point of view, some odorant bionanoparticles with enhanced bioactive properties (protection against oxidation, enhanced olfactive and long life smelling properties) and possible applications in cosmetic and toiletries were obtained and characterized. Both limonene and linalool enantiomers (d and l), dl-linalyl acetate, b-caryophyllene, benzaldehyde, g-decalactone, a-ionone, menthol, vanillin, and hydroxycitronellal were used as guest compounds. The encapsulation was achieved by crystallization from the ethanol-water solution. The GC-MS was used for odorant compound analysis and TG for nanoparticle analysis. a- Cyclodextrin release the odorant compounds earlier then the b-cyclodextrin, as indicated by thermogravimetric analysis. The benzaldehyde, menthol and vanillin were decomplexed at lower temperatures then 70�C and the majority of compounds were complexed at 1:1 stoichiometry ratio.

scholarly journals Silica Monolith for the Removal of Pollutants from Gas and Aqueous Phases

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1316
Author(s):  
Vanessa Miglio ◽  
Chiara Zaccone ◽  
Chiara Vittoni ◽  
Ilaria Braschi ◽  
Enrico Buscaroli ◽  
...  
Keyword(s):  
Rhodamine B ◽  
Water Solution ◽  
Synthesis Method ◽  
Textural Properties ◽  
Adsorption Properties ◽  
Water Soluble ◽  
Silica Monoliths ◽  
Physico Chemical ◽  
Gaseous Toluene ◽  
Mcm 41

This study focused on the application of mesoporous silica monoliths for the removal of organic pollutants. The physico-chemical textural and surface properties of the monoliths were investigated. The homogeneity of the textural properties along the entire length of the monoliths was assessed, as well as the reproducibility of the synthesis method. The adsorption properties of the monoliths for gaseous toluene, as a model of Volatile Organic Compounds (VOCs), were evaluated and compared to those of a reference meso-structured silica powder (MCM-41) of commercial origin. Silica monoliths adsorbed comparable amounts of toluene with respect to MCM-41, with better performances at low pressure. Finally, considering their potential application in water phase, the adsorption properties of monoliths toward Rhodamine B, selected as a model molecule of water soluble pollutants, were studied together with their stability in water. After 24 h of contact, the silica monoliths were able to adsorb up to the 70% of 1.5 × 10−2 mM Rhodamine B in water solution.

scholarly journals A Review on Coordination Properties of Al(III) and Fe(III) toward Natural Antioxidant Molecules: Experimental and Theoretical Insights

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2603
Author(s):  
Luana Malacaria ◽  
Giuseppina Anna Corrente ◽  
Amerigo Beneduci ◽  
Emilia Furia ◽  
Tiziana Marino ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Natural Antioxidants ◽  
Point Of View ◽  
Water Soluble ◽  
Natural Antioxidant ◽  
Theoretical Point ◽  
Structure And Properties ◽  
Coordination Properties ◽  
Soluble Molecule ◽  
Living Organisms

This review focuses on the ability of some natural antioxidant molecules (i.e., hydroxycinnamic acids, coumarin-3-carboxylic acid, quercetin, luteolin and curcumin) to form Al(III)- and Fe(III)-complexes with the aim of evaluating the coordination properties from a combined experimental and theoretical point of view. Despite the contributions of previous studies on the chemical properties and biological activity of these metal complexes involving such natural antioxidants, further detailed relationships between the structure and properties are still required. In this context, the investigation on the coordination properties of Al(III) and Fe(III) toward these natural antioxidant molecules might deserve high interest to design water soluble molecule-based metal carriers that can improve the metal’s intake and/or its removal in living organisms.

Theoretical Evaluation of Rheological State of Sand Cement Composite Systems with Polyoxyethylene Additive Using Topological Dynamics Concept

2016 ◽  
Vol 871 ◽  
pp. 96-103 ◽  
Author(s):  
Vladimir Erofeev ◽  
Aleksandr Bobryshev ◽  
Aleksandr Lakhno ◽  
Lenar Shafigullin ◽  
Ilnaz Khalilov ◽  
...  
Keyword(s):  
Water Solution ◽  
Cement Composite ◽  
Water Soluble ◽  
Viscosity Data ◽  
Active Components ◽  
Theoretical Evaluation ◽  
Composite Systems ◽  
Polymer Powder ◽  
Cement System ◽  
Phase Water

Presents the results of studies of contemporary materials in the field of rheological state. The topological mortar structure has been provided by theoretical evaluation of the rheological state of the cross-linked solutions and the experimental viscosity data of the sand cement mortar which has been modified by water-soluble additive – polyoxyethylene. The general model has been made for the structure of non-Newtonian liquideous systems including dilatant, pseudoplastic bodies with two main rheological active components in their structure – rigid and viscous phases. It is shown that in pseudoplastic systems, as the shear stress increases, the viscous phase grows because of the reduction of rigid phase content. In dilatant systems the converse situation has been observed. Furthermore, these phases are not clearly distinguishable, but to the contrary they are spatially interconnected in a complex way. The structure modeling has been made for non-Newtonian bodies using the Shklovskii-de Gennes model. The studies have found that the construction composite sand cement system is defined as the pseudoplastic body where cement and sand act as the rigid phase, water solution of polyoxyethylene – as the viscous phase. These findings can be used to prove the influence of polymer powder on the workability of dry mortar.

scholarly journals Analysis of Energy Characteristics of Rice and Coffee Husks Blends

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Cuthbert F. Mhilu
Keyword(s):  
Thermogravimetric Analysis ◽  
First Generation ◽  
Point Of View ◽  
Rice Husks ◽  
Material Degradation ◽  
Energy Characteristics ◽  
Hemicellulose Degradation ◽  
Active Interest ◽  
Retention Characteristics ◽  
Work Done

Production of first generation biofuels using food crops is under criticism over sustainability issues on food security. Tanzania is showing active interest in developing second generation biofuels to deal with some of such issues, especially from the feedstock point of view. This paper reports work done to determine energy characteristics of rice and coffee husks. The results show that coffee husks have better energy quality than rice husks, while heating values of coffee are 18.34 MJ/kg and 13.24 MJ/kg for rice husk. Thermogravimetric analysis made for coffee husks blended rice husks at a ratio of 75 : 25% vol. show better material degradation characteristics yielding low residual mass of 23.65%, compared to 26.50% of char and ash remaining in pure rice husks. Derivative thermogravimetric analysis shows comparable hemicellulose degradation peak values of −11.5 and −11.2 and cellulose −3.20 and −2.90 in pure coffee and rice husks, respectively. In coffee and rice husks blends, substantial reductions of hemicellulose and cellulose peaks were observed. Use of coffee and rice husks blends applying high temperature gasification would reduce the latter’s flammability, while increasing its flame retention characteristics, hence offering opportunities for production of clean syngas in a sustainable manner.

scholarly journals How the Chemical Properties of GBCAs Influence Their Safety Profiles In Vivo

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 58
Author(s):  
Quyen N. Do ◽  
Robert E. Lenkinski ◽  
Gyula Tircso ◽  
Zoltan Kovacs
Keyword(s):  
Human Brain ◽  
Chemical Properties ◽  
Point Of View ◽  
Water Soluble ◽  
Soluble Form ◽  
Clinical Implications ◽  
Kinetic Properties ◽  
Gadolinium Retention ◽  
Open Question

The extracellular class of gadolinium-based contrast agents (GBCAs) is an essential tool for clinical diagnosis and disease management. In order to better understand the issues associated with GBCA administration and gadolinium retention and deposition in the human brain, the chemical properties of GBCAs such as relative thermodynamic and kinetic stabilities and their likelihood of forming gadolinium deposits in vivo will be reviewed. The chemical form of gadolinium causing the hyperintensity is an open question. On the basis of estimates of total gadolinium concentration present, it is highly unlikely that the intact chelate is causing the T1 hyperintensities observed in the human brain. Although it is possible that there is a water-soluble form of gadolinium that has high relaxitvity present, our experience indicates that the insoluble gadolinium-based agents/salts could have high relaxivities on the surface of the solid due to higher water access. This review assesses the safety of GBCAs from a chemical point of view based on their thermodynamic and kinetic properties, discusses how these properties influence in vivo behavior, and highlights some clinical implications regarding the development of future imaging agents.

Effects of Cathodic Protection on Cracking of High-Strength Pipeline Steels

2010 ◽  
Author(s):  
M. Elboujdaini ◽  
R. W. Revie ◽  
M. Attard
Keyword(s):  
Hydrogen Embrittlement ◽  
Cathodic Protection ◽  
Cathodic Polarization ◽  
Water Solution ◽  
Reference Electrode ◽  
High Strength ◽  
Point Of View ◽  
Pipeline Steels ◽  
Different Levels ◽  
Reduction Index

A comparison was made between four strength levels of pipeline steels (X-70, X80, X-100 and the X-120) from the point of view of their susceptibility to hydrogen embrittlement under cathodic protection. The main aim was to determine whether the development of higher strength materials led to greater susceptibility to hydrogen embrittlement. This was achieved by straining at 2×10−6 s−1 after cathodic charging in a simulated dilute groundwater solution (NS4) containing 5% CO2/95% N2 (pH approximately 6.7). The results showed quantitatively the loss of ductility after charging, and the loss of ductility increases with strength level of the steel. All four steels exhibited a loss of ductility at overprotected charging potential and an increasing amount of brittleness on the fracture surface. Ductility in solution was measured under four different levels of cathodic protection, ranging from no cathodic protection to 500 mV of overprotection with respect to the usually accepted criterion of −850 mV vs. Cu/CuSO4 reference electrode. Experiments were carried out by straining during cathodic polarization in a simulated dilute ground water solution (NS-4 solution). Strain rates used were 2×10−6 s−1. After failure, the fracture surfaces were characterized by examination using scanning electron microscopy (SEM). Under cathodic protection, all four steels showed loss of ductility and features of brittle fracture. The loss of ductility under cathodic polarization was larger the greater the strength of the steel and the more active (i.e., more negative) the applied potential. The Ductility Reduction Index (DRI) was defined to quantify the reduction in ductility.

scholarly journals A water-soluble fluorescent chemosensor based on Asp functionalized naphthalimide for successive detection Fe3+ and H2PO4−

2018 ◽  
Vol 96 (4) ◽  
pp. 363-370 ◽  
Author(s):  
You-Ming Zhang ◽  
Xiao-Peng Chen ◽  
Guo-Yan Liang ◽  
Kai-Peng Zhong ◽  
Hong Yao ◽  
...  
Keyword(s):  
Fluorescence Quenching ◽  
Metal Ions ◽  
Aspartic Acid ◽  
High Selectivity ◽  
Fluorescent Sensor ◽  
Water Solution ◽  
Water Soluble ◽  
Selective Recognition ◽  
Actual Usage ◽  
Quenching Process

The selective recognition of target ions in water is very important and the development of novel water-soluble chemosensor is still an intriguing challenge. Herein, a novel water-soluble fluorescent sensor based on aspartic acid (Asp) functionalized 1,8-naphthalimide derivative (Asp-NI) has been designed and synthesized. The sensor Asp-NI could dissolve in water and successively detect Fe3+ and H2PO4− in water solution with high selectivity and sensitivity. The detection limits are 4.97 × 10−7 mol/L for Fe3+ and 5.27 × 10−6 mol/L for H2PO4−. Other coexistent competitive metal ions (Hg2+, Ag+, Ca2+, Cu2+, Co2+, Ni2+, Cd2+, Pb2+, Zn2+, Cr3+, and Mg2+) showed no interference in the Fe3+ detection process. The sensor Asp-NI could act as a Fe3+ and H2PO4− controlled “On–Off–On” fluorescent switch. More interestingly, the Fe3+ induced fluorescence quenching process could be totally reversed by the addition of H2PO4−, this “On–Off–On” switching process could be repeated several times with little fluorescence loss. Notably, the actual usage of sensor Asp-NI was further demonstrated by test kits.

Impurities in Commercial Saccharin. I. Impurities Soluble in Organic Solvents

1976 ◽  
Vol 59 (5) ◽  
pp. 1051-1058 ◽  
Author(s):  
Bozidar Stavrić ◽  
Raymond Klassen ◽  
W Arnold
Keyword(s):  
Organic Solvents ◽  
Water Solution ◽  
Water Soluble ◽  
Chromatographic Column ◽  
Gas Liquid Chromatography ◽  
Sodium Saccharin ◽  
Chemical Purity ◽  
Liquid Chromatographic ◽  
Chloroform Methanol ◽  
Sodium Form

Abstract Thirteen saccharin samples used for carcinogenicity tests in animals in various laboratories were analyzed for their chemical purity. Although most of the impurities were water-soluble, some were mainly soluble in organic solvents. These impurities were extracted with chloroform-methanol from a water solution of sodium saccharin. Samples obtained as acid-saccharin were converted to the sodium form before extraction. The major impurity in commercial saccharin, o-toluenesulfonamide, was also soluble in this system. Impurities were separated by gas-liquid chromatography of the underivatized, concentrated extract. Eleven major, well separated peaks were collected from the gas chromatographic column and identified by mass spectroscopy. Some of the peaks were compared with known standards. Qualitative and quantitative differences in impurities were observed among different saccharin samples. The identified impurities (in order of appearance from the gas-liquid chromatographic column) were as follows: o-toluenesulfonamide; p-toluenesufonamide; 1,2-benzisothiazole 1,1-dioxide; 1,2-benzisothiazoline 1,1-dioxide; diphenylsulfone; o,o′-ditolylsulfone; o,m′-ditolylsulfone, o,p′-ditolylsulfone; m,p′-ditolylsulfone; p,p′-ditolylsulfone, and tetracosane.

scholarly journals Contributions to the Knowledge of Soil Resources of Cuca Plain

2017 ◽  
Vol 5 (2) ◽  
pp. 13
Author(s):  
Anca -Luiza Stănilă ◽  
Mihail Dumitru ◽  
Cătălin Cristian Simota
Keyword(s):  
Environmental Factors ◽  
Soil Cover ◽  
Geographical Area ◽  
River System ◽  
Parent Material ◽  
Point Of View ◽  
Soil Resources ◽  
North Eastern ◽  
A Subunit ◽  
Pedogenetic Processes

The territory to which we refer is located in the geographical area of the Romanian Plain, north-eastern sector, representing a subunit of Plain Covurlui. From the administrative point of view this territory belongs entirely Galaţi County. Since the first review of Cuca Plain territory fragmentation is found in the form of ridges interfluvial oriented northwest-southeast separated by a river system consistent. The provision gives relief peaks ordely character of monotony. Starting from the idea that the soil appears as a product of the interaction of many factors, we can say that the formation of soil cover of Cuca Plain took part relief, parent material, climate, groundwater, vegetation, human activity. Under the influence of environmental factors and pedogenetic processes in the Cuca Plain were differentiated two classes of soils, namely: protisols and cernisols.

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