Preparation and Characteristics of Chitin-Gelatin Composite Film

2013 ◽  
Vol 690-693 ◽  
pp. 1243-1246
Author(s):  
Ya Juan Wang ◽  
Lan Jiang ◽  
Shuang Xi Shao
Keyword(s):  
Composite Film ◽  
Carbonyl Group ◽  
Gelatin Film ◽  
Hydroxyl Group ◽  
Cross Link ◽  
Denaturation Temperature ◽  
Equilibrium Swelling ◽  
Swelling Rate ◽  
Equilibrium Swelling Ratio ◽  
The Stability

Using hydrogen peroxide as oxidant, the chitin has been oxidized under a certain conditions. And then the IR and SEM of product has been tested, and the results show that hydroxyl group can be transform carbonyl group. What’s more, the oxidation reaction occurred not only in the surface of chitin, but also in its interior. Owing to the reaction of carbonyl group in the oxidation product, this chitin derivatives was applied to cross link with gelatin material, and the properties of modified gelatin film then has been tested. The results of Differential Scanning Calorimeter (DSC) show that the denaturation temperature of composite gelatin film has been enhanced to 109.8°C, and its swelling rate also has been slow, which ensure the stability as a kind of biomaterials, such as microcapsule and microspheres. And the time of native gelatin film achieving equilibrium swelling state is 9 minutes, and the time is 14 minutes for composite film, which means the oxidized chitin can delay the complete swelling rate. And the equilibrium swelling ratio of native gelatin film is larger than that of composite film. Therefore, the composite film will have a good prospects as a kind of potential biomedical.

Physical Stability and Lyophilization of Poly(ε-caprolactone)-b-Poly(ethyleneglycol)-b-Poly(ε-caprolactone) Micelles

2006 ◽  
Vol 6 (9) ◽  
pp. 3032-3039 ◽  
Author(s):  
Yong Hu ◽  
Yin Ding ◽  
Yuan Li ◽  
Xiqun Jiang ◽  
Changzheng Yang ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Carbonyl Group ◽  
Fluorescence Spectra ◽  
Physical Stability ◽  
Storage Period ◽  
Aqueous Dispersion ◽  
Hydroxyl Group ◽  
Core Shell ◽  
Ft Ir ◽  
The Stability

The stability and lyophilization of core–shell PCL-PEG-PCL micelles were investigated by fluorescence spectra, DLS, DSC, WAXD, and FT-IR. The prepared micelles were not stable when they were stored in aqueous dispersion under different condition. Their size increased in the first 20 days and decreased gradually when the storage period was extended. Lyophilization experiment showed that the cryoprotective agent (glucose) was an essential additive to protect the micelles from aggregating during the lyophilization process. After lyophilizing and re-dispersion, the PCL-PEG-PCL micelles became larger in size compared to as-prepared ones. DSC, WAXD, and IR measurements indicated the hydrogen bonding was formed between the hydroxyl group in glucose and the carbonyl group in PCL-PEG-PCL micelles. The effect of added glucose on protection of micelles from aggregation can be explained by the formation of hydrogen bonding with PCL-PEG-PCL micelles and the formation of solid glucose matrix.

scholarly journals ACTIVITY SCREENING AND STRUCTURE MODIFICATION OF ARTOCARPIN AGAINST ACE2 AND MAIN PROTEASE THROUGH IN SILICO METHOD

2021 ◽  
pp. 192-198
Author(s):  
MUHAMMAD FAUZI ◽  
ARIS FADILLAH ◽  
FAUZI RAHMAN ◽  
JUWITA RAMADHANI ◽  
KARINA ERLIANTI ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
In Silico ◽  
Docking Simulation ◽  
Positive Control ◽  
Hydroxyl Group ◽  
Artocarpus Altilis ◽  
Main Protease ◽  
Activity Screening ◽  
The Stability ◽  
The Right

Objective: SARS-CoV-2 is a type of coronavirus that causes COVID-19 disease. Currently, the right and effective drug for the treatment of COVID-19 has not been found. Artocarpin in the breadfruit plant (Artocarpus altilis), which was tested, has been shown to have antiviral activity. However, artocarpin has a hydroxyl group that can undergo oxidation within a certain time, thereby reducing the stability of the compound and non-specific antiviral activity. Methods: In this study, the structural modification of artocarpin was carried out to obtain compounds with anticoronavirus activity with good physicochemical properties. This research was conducted in silico, including molecular docking simulation, bioavailability prediction, and preADMET. Results: The top 20 modified compounds were selected from each target's top 3 compounds, which had better bond energies compared to the positive control. These 3 compounds have the potential to inhibit ACE2 and Mpro receptors and 1 compound are better at inhibiting both. Conclusion: From the results of the research conducted, we conclude that the 3 best compounds can be potential candidates that can be developed as COVID-19 therapy.

scholarly journals A Simple Colorimetric Method for the Determination of Raloxifene Hydrochloride in Pharmaceuticals Using Modified Romini’s Reagent

2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
Kovvuru Praneeth Kumar Reddy ◽  
Kale Muni Sai Prathap ◽  
Hemraj Sharma ◽  
Kondareddy Vinod Kumar
Keyword(s):  
Sodium Nitroprusside ◽  
Colorimetric Assay ◽  
Bathochromic Shift ◽  
Colorimetric Method ◽  
Coupling Reaction ◽  
Hydroxyl Group ◽  
Stoichiometric Ratio ◽  
The Stability ◽  
Raloxifene Hydrochloride ◽  
Routine Assay

An analytical method has been developed based on a colorimetric assay for the estimation of raloxifene hydrochloride, followed by validation of the optimized method by using the ICH guidelines. The new method, aromatic ring derivatization technique, is based on a coupling reaction using modified Romini’s reagent in which sodium nitroprusside is used as a chromogenic derivatizing reagent. Raloxifene contains a phenolic hydroxyl group, containing reactive hydrogen. This reactive proton reacts with sodium nitroprusside and reduces it to sodium meta-hydrogen ferrocyano nitrate, which is a colored product. Optimization studies revealed that the coupling reaction was very rapid and completed in less than 1 minute. A 1 : 1 drug-to-reagent stoichiometric ratio was obtained for the azo dye formed. The azo adduct formed exhibits a bathochromic shift with absorption maximum λmax at 440 nm, which was selected as the analytical wavelength. The drug seems to be linear, which was established via the regression analysis from 20 to 120μg/ml. LOD and LOQ of the developed method were found to be 1.807μg/ml and 5.47μg/ml, respectively. Interday and intraday precision was studied, and %RSD was less than 2. Since the stability of the drug and the reagent was found to be predominantly massive, this method can be used for the formulation of raloxifene hydrochloride . The method can be extended for the routine assay of raloxifene formulations.

STUDIES ON LIGNIN AND RELATED COMPOUNDS.: VIII. A KINETIC STUDY OF THE ACTION OF SULPHUROUS ACID ON LIGNIN AND RELATED COMPOUNDS

1931 ◽  
Vol 5 (1) ◽  
pp. 1-47 ◽  
Author(s):  
Charles A. Sankey ◽  
Harold Hibbert
Keyword(s):  
Carbonyl Group ◽  
Addition Product ◽  
Heterocyclic Ring ◽  
Acid Group ◽  
Cyclic Ketones ◽  
Reactive Group ◽  
Experimental Conditions ◽  
Commercial Process ◽  
The Stability ◽  
Related Compounds

Electrical conductivity measurements have been made over the temperature range 18–145 °C. of reaction mixtures of sulphurous acid and a large number of type compounds, and data obtained on the stability of the resulting sulphonic acids and the mobility of the equilibria involved. The compounds investigated include saturated and unsaturated aldehydes; saturated, unsaturated and cyclic ketones; phenols; substances in which an ethylene linkage is the only reactive group; furane derivatives; and substances containing pyrone rings.The results are discussed from the standpoints of structure and reaction mechanism. The sulphonic acids of nuclear aldehydes, saturated ketones and cylic ketones are typically unstable. With compounds containing an ethylene linkage conjugated with a carbonyl group, addition normally takes place in the 1:4 positions and is followed by hydrogen migration. Where an ethylene linkage is the only reactive group present, addition proceeds only very slowly and at high temperatures. The difficulty of effecting a reaction between sulphurous acid and phenols in their tautomeric alicyclic forms is indicated by the non-reactivity of resorcinol, and the formation of only a small percentage of an extremely unstable derivative by phloroglucinol. Furfuryl alcohol and glucal are shown to form oxonium derivatives which serve as intermediates for the entry of the sulphonic acid group into the ring system.Conductivity-temperature curves for lignosulphonic acids from various sources indicate that the products are sulphonic acids of the —C = C—type. Other evidence points to an oxonium addition product with a ring oxygen as being a probable intermediate in the formation of the final and more stable lignosulphonic acid. The relation of such a mechanism to the experimental conditions employed in the commercial process of the manufacture of sulphite pulp is indicated.The formation of lignosulphonic acids through tautomerization of a phenolic nucleus is highly improbable. Also for such formation a carbonyl group does not necessarily have to be present. Strong additional evidence is presented for the presence of a heterocyclic ring containing oxygen and for an ethylene linkage in the lignin molecule. The latter is indicated to be in the same ring system as the oxygen atom.

Fabrication and antimicrobial effects of silver nanoparticle-poly(N-isopropylacrylamide)-poly(ferrocenylsilane) hydrogel composites

2012 ◽  
Vol 1453 ◽  
Author(s):  
Xiaofeng Sui ◽  
Xueling Feng ◽  
Andrea Di Luca ◽  
Clemens A. van Blitterswijk ◽  
Lorenzo Moroni ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Light Emitting ◽  
Uv Led ◽  
Hydrogel Network ◽  
Redox Responsive ◽  
Equilibrium Swelling ◽  
Hydrogel Composites ◽  
Equilibrium Swelling Ratio ◽  
Strong Antimicrobial Activity

ABSTRACTNovel hydrogels composed of thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) and redox-responsive poly(ferrocenylsilane) (PFS) macromolecules were formed by photopolymerization. PFS chains bearing acrylate side groups were copolymerized with NIPAM and N,N’-methylenebisacrylamide in tetrahydrofuran in a predetermined ratio under ultraviolet light-emitting diode (UV-LED) irradiation at a wavelength of 365 nm, in the presence of a photoinitiator. Crosslinking occurred smoothly, providing homogeneous hydrogels. The equilibrium swelling ratio, rheology and morphology of these hybrid PNIPAM-PFS-based hydrogels were investigated. In-situ fabrication of silver nanoparticles inside the hydrogel network via reduction of silver nitrate by the PFS chains led to hydrogel composites. These composites showed strong antimicrobial activity while maintaining a high biocompatibility with cells.

scholarly journals The effects of certain glycols, substituted glycols and related organic solvents on the thermal stability of soluble collagen

1971 ◽  
Vol 125 (2) ◽  
pp. 599-604 ◽  
Author(s):  
G. J. Hart ◽  
A. E. Russell ◽  
D. R. Cooper
Keyword(s):  
Thermal Stability ◽  
Optical Rotation ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Thermal Transition ◽  
Denaturation Temperature ◽  
Rotation Measurement ◽  
Skin Collagen ◽  
Positional Isomerism ◽  
Thermal Stability Of

The effects of a number of related diols, substituted diols and glycerol on the thermal stability of acid-soluble calf skin collagen were investigated. Thermal transition temperatures were determined by optical rotation measurement. Short-chain diols with terminal hydroxyl groups, i.e. ethylene glycol and propane-1,3-diol, stabilized the protein at all accessible concentrations. Stabilization was also observed with glycerol and diethylene glycol. Higher homologues in the diol series produced various effects, as did hydroxyl-group positional isomerism. Monoalkyl substitution of diols progressively lowered the denaturation temperature of collagen. Results are discussed in relation to possible mechanisms of perturbant action.

scholarly journals Sorption of Richlokain on Polycarboxylic Acid Gels

2016 ◽  
Vol 5 (4) ◽  
pp. 311
Author(s):  
Marat K. Beysebekov ◽  
Assel K. Toktabaeva ◽  
Zharylkasyn A. Abilov
Keyword(s):  
Ir Spectroscopy ◽  
Complex Formation ◽  
Sorption Process ◽  
Reagent Concentration ◽  
Polycarboxylic Acid ◽  
Polymethacrylic Acid ◽  
Cross Link ◽  
Ionic Force ◽  
Equilibrium Swelling ◽  
Hydrophobic Nature

The sorption immobilization of richlokain on gels of polyacrylic acid (PAAG) or polymethacrylic acid (PMAAG) has been studied. By a number of methods – equilibrium swelling, potentiometry, IR-spectroscopy, and sorption it has been shown that binding of richlokain with these gels leads to the complex formation owing to the electrostatic interaction, which is stabilised by the hydrophobic and hydrogen bonds. Effect of an ionic force, reagent concentration, cross-link degree, hydrophobic nature of gels, and pH of solutions on the sorption process has been studied.

scholarly journals Zinc-Chelating Compounds as Inhibitors of Human and Bacterial Zinc Metalloproteases

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 56
Author(s):  
Fatema Rahman ◽  
Imin Wushur ◽  
Nabin Malla ◽  
Ove Alexander Høgmoen Åstrand ◽  
Pål Rongved ◽  
...  
Keyword(s):  
Carbonyl Group ◽  
Virulence Factors ◽  
Bacterial Infections ◽  
Bacterial Virulence ◽  
Hydroxyl Group ◽  
Matrix Metalloprotease ◽  
Pyridine Nitrogen ◽  
Zinc Metalloproteases ◽  
New Treatment ◽  
Chelating Compounds

Inhibition of bacterial virulence is believed to be a new treatment option for bacterial infections. In the present study, we tested dipicolylamine (DPA), tripicolylamine (TPA), tris pyridine ethylene diamine (TPED), pyridine and thiophene derivatives as putative inhibitors of the bacterial virulence factors thermolysin (TLN), pseudolysin (PLN) and aureolysin (ALN) and the human zinc metalloproteases, matrix metalloprotease-9 (MMP-9) and matrix metalloprotease-14 (MMP-14). These compounds have nitrogen or sulfur as putative donor atoms for zinc chelation. In general, the compounds showed stronger inhibition of MMP-14 and PLN than of the other enzymes, with Ki values in the lower μM range. Except for DPA, none of the compounds showed significantly stronger inhibition of the virulence factors than of the human zinc metalloproteases. TPA and Zn230 were the only compounds that inhibited all five zinc metalloproteinases with a Ki value in the lower μM range. The thiophene compounds gave weak or no inhibition. Docking indicated that some of the compounds coordinated zinc by one oxygen atom from a hydroxyl or carbonyl group, or by oxygen atoms both from a hydroxyl group and a carbonyl group, and not by pyridine nitrogen as in DPA and TPA.

Surface Modification of ZrO2 by Silane and the Stability Study

2015 ◽  
Vol 764-765 ◽  
pp. 98-101
Author(s):  
Jyh Herng Chen ◽  
Miao Yi Hsieh ◽  
Bo Hua Chen
Keyword(s):  
Surface Modification ◽  
Composite Film ◽  
Organic Phase ◽  
Polymer Matrix ◽  
Stability Study ◽  
Organic Film ◽  
Main Challenge ◽  
Silane Modification ◽  
Promising Application ◽  
The Stability

Transparent inorganic-organic film with nanoparticle shows promising application in various technology field. In order to obtain transparent inorganic-organic composite film, the main challenge is to homogeneously disperse inorganic nanoparticle in polymer matrix without coagulation. This study demonstrated that silane-modification can obtain ZrO2 with chemically bonded silane. The ZrO2 nanoparticle shows good stability in various organic phase. Thus prepared inorganic-organic composite film has transparence as high as 80%.

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