Thermodynamics and acoustic effects of quercetin on micellization and interaction behaviour of CTAB in different hydroethanol solvent systems

AbstractFlavonoids amongst the class of secondary metabolites possess numerous health benefits, are known for its use in pharmaceutical industry. Quercetin, a flavonoid has more prominent medical advantages however its utilization is constrained because of various instability and insolubility issues and therefore, taken into consideration for studying its physico-chemical properties. In view of that, the thermodynamic and thermoacoustic properties of quercetin were examined in presence of cationic surfactant cetyltrimethylammonium bromide (CTAB) at different hydroethanolic concentrations and temperatures. The conductivity studies were used to calculate change in enthalpy (∆Hom), change in entropy (∆Som) and change in Gibbs free Energy (∆Gom) of micellization. The interactions between quercetin and CTAB were found to be endothermic, entropically controlled and spontaneous. Further, ultrasonic sound velocity and density studies were carried out and utilized for the calculation of thermoacoustic parameters i.e. apparent molar volume and apparent molar compressibility. Thermoacoustic properties revealed that at higher surfactant concentration, hydrophobic interactions are dominant. The results suggested that the flavonoid-surfactant interactions in hydroethanolic solutions is more favourable as compared with aqueous solution. Overall, the data is favourable for the framework to be used for detailing advancement, drug development, drug industry, pharmaceutical industry, medical administration and formulation development studies.

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A review on conductometric studies of electrolytes in mixed solvent systems to understand ion-ion and ion-solvent interactions

Biointerface Research in Applied Chemistry ◽

10.33263/briac103.355360 ◽

2020 ◽

Vol 10 (3) ◽

pp. 5355-5360

Keyword(s):

Mixed Solvent ◽

Mixed Solvents ◽

Chemical Properties ◽

Electrolyte Solutions ◽

Molar Conductance ◽

Extensive Literature ◽

Solvent Interactions ◽

Physico Chemical ◽

Wide Range ◽

Solvent Systems

The study of ion- solvent interaction is of much importance to investigate the nature of different solutions. Measurement of electrical conductivity and evaluation of physico-chemical properties, such as molar conductance, limiting molar conductance, ion-pair association, Walden product etc. shade light on different intermolecular interactions present in electrolyte solutions. Solvation properties can be varied by mixing two or more solvents. An extensive literature survey on conductometric studies has been carried out on different electrolytes dissolved in a wide range of mixed solvent systems. The reported results show that strong solute-solute, solute-solvent and solvent-solvent interactions are responsible for the physico- chemical behavior of a solution in mixed solvents.

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Gelatin: sources, preparation and application in food and biomedicine

Chemical Bulletin of Kazakh National University ◽

10.15328/cb1112 ◽

2020 ◽

pp. 28-46

Author(s):

Elvira Shatabayeva ◽

Grigoriy Mun ◽

Yerengaip Shaikhutdinov ◽

Vitaliy Khutoryanskiy

Keyword(s):

Pharmaceutical Industry ◽

Food Packaging ◽

Chemical Properties ◽

Essential Amino Acids ◽

Biologically Active ◽

Wound Dressings ◽

Human Gastrointestinal Tract ◽

Physico Chemical ◽

Anti Cancer ◽

Cell Adhesion And Proliferation

Gelatin is a proteinaceous substance composed of all the essential amino acids (except tryptophan) and derived from collagen using a hydrolysis technique. Hydrogels and modified composites based on gelatin are widely used in the food industry, biomedicine, pharmaceutical industry and food packaging materials due to their biocompatibility, biodegradability, nonimmunogenicity and ability to stimulate cell adhesion and proliferation. Gelatin can absorb 5-10 times its weight of water and is the main ingredient of hard and soft capsules in pharmaceutical industry. It melts above 30°C and easily releases biologically active compounds, nutrients and drugs in human gastrointestinal tract. In addition, gelatin contains arginine-glycine-asparagine RGD-sequences in the polymer structure and contributes to various functions such as antioxidant, anti-hypertensive, anti-microbial, tissue regeneration, wound healing, enhances bone formation and anti-cancer therapy. This article reports a brief overview of gelatin sources, gelatin preparation processes and its physico-chemical properties, as well as advances in the preparation of gelatin-based composite materials and hydrogels for tissue engineering, drug delivery, wound dressings, active packaging using various cross-linking techniques.

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A review on conductometric studies of electrolytes in mixed solvent systems to understand ion-ion and ion-solvent interactions

Biointerface Research in Applied Chemistry ◽

10.33263/briac102.332337 ◽

2020 ◽

Vol 10 (2) ◽

pp. 5332-5337

Keyword(s):

Mixed Solvent ◽

Mixed Solvents ◽

Chemical Properties ◽

Electrolyte Solutions ◽

Molar Conductance ◽

Extensive Literature ◽

Solvent Interactions ◽

Physico Chemical ◽

Wide Range ◽

Solvent Systems

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From Solution to Crystals With a Physico-Chemical Aspect

Crystallization of Nucleic Acids and Proteins ◽

10.1093/oso/9780199636792.003.0014 ◽

1999 ◽

Author(s):

M. Riès-Kautt ◽

A. Ducruix

Keyword(s):

Crystal Growth ◽

Tertiary Structure ◽

Hydrophobic Interactions ◽

Chemical Properties ◽

Biological Properties ◽

Biological Macromolecules ◽

Biological Macromolecule ◽

Physico Chemical ◽

Crystal Contacts ◽

Solute Interactions

Biological macromolecules follow the same thermodynamic rules as inorganic or organic small molecules concerning supersaturation, nucleation, and crystal growth (1). Nevertheless macromolecules present particularities, because the intramolecular interactions responsible of their tertiary structure, the intermolecular interactions involved in the crystal contacts, and the interactions necessary to solubilize them in a solvent are similar. Therefore these different interactions may become competitive with each other. In addition, the biological properties of biological macromolecules may be conserved although the physico-chemical properties, such as the net charge, may change depending on the crystallization conditions (pH, ionic strength, etc.). A charged biological macromolecule requires counterions to maintain the electroneutrality of the solution; therefore it should be considered as a protein (or nucleic acid) salt with its own physico-chemical properties, depending on the nature of the counterions. To crystallize a biological macromolecule, its solution must have reached supersaturation which is the driving force for crystal growth. The understanding of the influence of the crystallization parameters on protein solubility of model proteins is necessary to guide the preparation of crystals of new proteins and their manipulation. Only the practical issues are developed in this chapter, and the reader should refer to recent reviews (2-4) for a description of the fundamental physical chemistry underlying crystallogenesis. The solubilization of a solute (e.g. a biological macromolecule) in an efficient solvent requires solvent-solute interactions, which must be similar to the solvent-solvent interactions and to the solute-solute interactions of the compound to be dissolved. All of the compounds of a protein solution (protein, water, buffer, crystallizing agents, and others) interact with each other via various, often weak, types of interactions: monopole-monopole, monopole-dipole, dipole-dipole, Van der Waals hydrophobic interactions, and hydrogen bonds. Solubility is defined as the amount of solute dissolved in a solution in equilibrium with its crystal form at a given temperature. For example, crystalline ammonium sulfate dissolves at 25°C until its concentration reaches 4.1 moles per litre of water, the excess remaining non-dissolved. More salt can be dissolved when raising the temperature, but if the temperature is brought back to 25°C, the solution becomes supersaturated, and the excess of salt crystallizes until its concentration reaches again its solubility value at 25°C (4.1 moles per litre of water).

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Removal of Direct dyes with Alginic acid

Journal of the Mexican Chemical Society ◽

10.29356/jmcs.v59i3.38 ◽

2017 ◽

Vol 59 (3) ◽

Author(s):

Virginia-Francisca Marañón-Ruiz

Keyword(s):

Calcium Ion ◽

Electrostatic Interactions ◽

Dye Removal ◽

Alginic Acid ◽

Hydrophobic Interactions ◽

Chemical Properties ◽

Direct Dyes ◽

Physico Chemical ◽

Direct Blue ◽

Direct Black 22

<p class="BDAbstract"><span lang="EN-US">The interaction of Alginic acid with three direct dyes (Direct blue 1, Direct red 81, and Direct black 22) was studied. It was found that as a result of this interaction formation of adducts after addition of calcium ion, facilitates their removal from aqueous solution. Our results suggest a relationship among physico-chemical properties of each dye and its removal efficiency. The main mechanisms involved in dye removal are electrostatic interactions, hydrogen bonding and hydrophobic interactions.</span></p>

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Assessing the Influence of Dyes Physico-Chemical Properties on Incorporation and Release Kinetics in Silk Fibroin Matrices

Polymers ◽

10.3390/polym13050798 ◽

2021 ◽

Vol 13 (5) ◽

pp. 798

Author(s):

Bruno Thorihara Tomoda ◽

Murilo Santos Pacheco ◽

Yasmin Broso Abranches ◽

Juliane Viganó ◽

Fabiana Perrechil ◽

...

Keyword(s):

Silk Fibroin ◽

Biomedical Applications ◽

Hydrophobic Interactions ◽

Release Kinetics ◽

Chemical Properties ◽

Release Time ◽

Prolonged Release ◽

Physico Chemical ◽

Release Device ◽

Electrostatic And Hydrophobic Interactions

Silk fibroin (SF) is a promising and versatile biodegradable protein for biomedical applications. This study aimed to develop a prolonged release device by incorporating SF microparticles containing dyes into SF hydrogels. The influence of dyes on incorporation and release kinetics in SF based devices were evaluated regarding their hydrophilicity, molar mass, and cationic/anionic character. Hydrophobic and cationic dyes presented high encapsulation efficiency, probably related to electrostatic and hydrophobic interactions with SF. The addition of SF microparticles in SF hydrogels was an effective method to prolong the release, increasing the release time by 10-fold.

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Decoration of specific sites on freeze-fractured membranes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081565 ◽

1978 ◽

Vol 36 (2) ◽

pp. 140-141

Author(s):

H. Gross ◽

H. Moor

Keyword(s):

Pure Water ◽

Freeze Fracture ◽

Chemical Properties ◽

Surface Forces ◽

Sulfate Pentahydrate ◽

Copper Sulfate Pentahydrate ◽

Physico Chemical ◽

Water Of Hydration ◽

Small Container ◽

Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

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PHYSICO CHEMICAL PROPERTIES OF NICKEL OXIDE AT HIGH TEMPERATURE

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1976798 ◽

1976 ◽

Vol 37 (C7) ◽

pp. C7-438-C7-442 ◽

Cited By ~ 2

Author(s):

R. FARHI ◽

G. PETOT-ERVAS

Keyword(s):

High Temperature ◽

Nickel Oxide ◽

Chemical Properties ◽

Physico Chemical

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Physico-Chemical Properties of Recombinant Desulphatohirudin

Thrombosis and Haemostasis ◽

10.1055/s-0038-1645073 ◽

1990 ◽

Vol 63 (03) ◽

pp. 499-504 ◽

Cited By ~ 4

Author(s):

A Electricwala ◽

L Irons ◽

R Wait ◽

R J G Carr ◽

R J Ling ◽

...

Keyword(s):

Molecular Weight ◽

Gel Filtration ◽

Chemical Properties ◽

Alpha Helix ◽

Apparent Molecular Weight ◽

Correlation Spectroscopy ◽

Nmr Studies ◽

Recombinant Hirudin ◽

Physico Chemical ◽

Recombinant Molecule

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)

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