Thermal stability studies of a globular protein in aqueous poly(ethylene glycol) by 1H NMR

2000 ◽  
Vol 51 (4) ◽  
pp. 410-421 ◽  
Author(s):  
Timothy J. Hancock ◽  
James T. Hsu
Keyword(s):  
Thermal Stability ◽  
Ethylene Glycol ◽  
1H Nmr ◽  
Globular Protein ◽  
Stability Studies ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

scholarly journals Sizing and Thermal Stability of Prepared Tetraaminophthalocyaninatocopper(II) Derivatives-grafted Polymers

2016 ◽  
Vol 13 (2) ◽  
pp. 221-234
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thermal Stability ◽  
Ethylene Glycol ◽  
Group Analysis ◽  
Condensation Polymerization ◽  
Grafted Polymers ◽  
Poly Ethylene Glycol ◽  
Molecular Weights ◽  
Poly Ethylene ◽  
Thermal Stability Of ◽  
End Group

Different polymers were prepared by condensation polymerization of sebacic anhydride and adipic anhydride with ethylene glycol and poly(ethylene glycol). Their number average molecular weights were determined by end group analysis. Then, they were grafted on the prepared phthalocyaninatocopper(II) compounds with the general formula (NH2)4PcCu(II) having amino groups of 3,3',3'',3'''- or 4,4',4'',4'''- positions. All prepared polymers, compounds, and phthalocyaninatocopper(II)-grafted polymers were characterized by FTIR. The sizing measurements were carried out in 3,3',3'',3'''- (NH2)4PcCu(II) and 4,4',4'',4'''- (NH2)4PcCu(II) compounds with and without grafting polymers. The results showed that the grafting process led to decreasing in particle size and increasing in surface area. The grafting process was reflected positively on the thermal degradation of 3,3',3'',3'''- (NH2)4PcCu(II) and 4,4',4'',4'''- (NH2)4PcCu(II) grafted polymers. They had higher thermal stability accompanied with higher char residue and T50% weight loss with 3,3',3'',3'''-(NH2)4PcCu(II) and their grafted polymers being the best.

Encapsulation of Lanthanide β-diketone Hybrids in Organic Oligomer Poly(ethylene glycol) 400

2015 ◽  
Vol 1102 ◽  
pp. 125-128
Author(s):  
Hua Ti Li ◽  
Dong Liu ◽  
Ying Li ◽  
Jie Lin Wang ◽  
Xia Wang
Keyword(s):  
Thermal Stability ◽  
Ethylene Glycol ◽  
Hybrid Materials ◽  
Mesoporous Material ◽  
Organic Ligand ◽  
Poly Ethylene Glycol ◽  
Characteristic Emission ◽  
Hybrid Precursor ◽  
Poly Ethylene ◽  
The Eu

The organic ligand 2-Thenoyltrifluoroacetone (TTA) which was selected as molecular bridge for sensitization of europium and terbium ions were modified by 3-(triethoxysilyl)-propylisocyanate (TEPIC) to obtain the hybrid precursor TTA-Si. Then the solution of Eu(NO3)3 and Tb(NO3)3 were added in the presence of tetraethylorthosilicate (TEOS). The binary lanthanide organic/inorganic hybrid material were obtained. The ternary hybrid materials were obtained by adding the solution of Eu(NO3)3 and Tb(NO3)3 and Poly (ethylene glycol) (PEG400). We investigated the thermal stability and luminescence properties of hybrids and found that the ternary hybrid materials exhibit better thermal stability and stronger emission intensity. Furthermore, compared with the binary mesoporous material Eu-(TTA-Si)3 and Tb-(TTA-Si)3, the ternary mesoporous material Eu-(TTA-Si)3-PEG and Tb-(TTA-Si)3-PEG exhibits the characteristic emission of the Eu3+ and Tb3+ ion with a higher luminescence intensity, suggesting that the introduction of PEG is of benefit for the sensitization of Eu3+ and Tb3+ luminescence, by replacing H2O groups that can quench the luminescence of Eu3+ and Tb3+ ions.

scholarly journals Synthesis of Mono- and Dithiols of Tetraethylene Glycol and Poly(ethylene glycol)s via Enzyme Catalysis

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 228 ◽  
Author(s):  
Prajakatta Mulay ◽  
Gayatri Shrikhande ◽  
Judit Puskas
Keyword(s):  
Nmr Spectroscopy ◽  
Ethylene Glycol ◽  
1H Nmr ◽  
Enzyme Catalysis ◽  
1H Nmr Spectroscopy ◽  
13C Nmr Spectroscopy ◽  
Tetraethylene Glycol ◽  
Candida Antarctica Lipase ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

This paper investigates the transesterification of methyl 3-mercaptopropionate (MP-SH) with tetraethylene glycol (TEG) and poly(ethylene glycol)s (PEG)s catalyzed by Candida antarctica Lipase B (CALB) without the use of solvent (in bulk). The progress of the reactions was monitored by 1H-NMR spectroscopy. We found that the reactions proceeded in a step-wise manner, first producing monothiols. TEG-monothiol was obtained in 15 min, while conversion to dithiol took 8 h. Monothiols from PEGs with Mn = 1000 and 2050 g/mol were obtained in 8 and 16 h, respectively. MALDI-ToF mass spectrometry verified the absence of dithiols. The synthesis of dithiols required additional fresh CALB and MP-SH. The structure of the products was confirmed by 1H-NMR and 13C-NMR spectroscopy. Enzyme catalysis was found to be a powerful tool to effectively synthesize thiol-functionalized TEGs and PEGs.

scholarly journals Optimization of Polyarginine-Conjugated PEG Lipid Grafted Proliposome Formulation for Enhanced Cellular Association of a Protein Drug

Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 272 ◽  
Author(s):  
Amolnat Tunsirikongkon ◽  
Yong-Chul Pyo ◽  
Dong-Hyun Kim ◽  
Sang-Eun Lee ◽  
Jeong-Sook Park
Keyword(s):  
Ethylene Glycol ◽  
1H Nmr ◽  
Protein Drug ◽  
Poly Ethylene Glycol ◽  
Cellular Toxicity ◽  
Association Pattern ◽  
Ft Ir ◽  
Poly Ethylene

The purpose of this study was to develop an oral proliposomal powder of protein using poly-l-arginine-conjugated 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol) (DSPE-PEG) (PLD) for enhancing cellular association upon reconstitution and to compare its effects with a non-grafted and PEGylated formulation. Cationic proliposome (CATL), PLD-grafted CATL (PLD-CATL), PEGylated CATL (PEG CATL), and PLD grafted-PEG CATL (PLD-PEG CATL) were prepared and compared. Successful conjugation between poly-l-arginine and DSPE-PEG was confirmed by 1H NMR and FT-IR. PLD was successfully grafted onto the proliposomal powder during the slurry process. Although reconstituted liposomal sizes of CATL and PLD-CATL were increased by agglomeration, PEGylation reduced the agglomeration and increased the encapsulation. The viabilities of cells treated with both CATL and PLD-CATL formulations were low but increased following PEGylation. With regard to cellular association, PLD-CATL enhanced cellular association/uptake more rapidly than did CATL. Upon PEGylation, PEG CATL showed a lower level of cellular association/uptake compared with CATL while PLD-PEG CATL did not exhibit the rapid cellular association/uptake as seen with PLD-CATL. However, PLD-PEG CATL still enhanced the higher cellular association/uptake than PEG CATL did without PLD. In conclusion, proliposomes with PLD could accelerate cellular association/uptake but also caused high cellular toxicity. PEGylation reduced cellular toxicity and also changed the cellular association pattern of the PLD formulation.

Dynamical aspects of water-poly(ethylene glycol) solutions studied by 1H NMR

2016 ◽  
Vol 222 ◽  
pp. 94-100 ◽  
Author(s):  
Manazael Z. Jora ◽  
Marcus V.C. Cardoso ◽  
Edvaldo Sabadini
Keyword(s):  
Ethylene Glycol ◽  
1H Nmr ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

1H-NMR characterization of poly(ethylene glycol) and polydimethylsiloxane copolymer

2016 ◽  
Author(s):  
Ain Athirah Zainuddin ◽  
Rizafizah Othaman ◽  
Wan Syaidatul Aqma Wan Mohd Noor ◽  
Farah Hannan Anuar
Keyword(s):  
Ethylene Glycol ◽  
1H Nmr ◽  
Poly Ethylene Glycol ◽  
Nmr Characterization ◽  
Poly Ethylene

Preparation of poly(L-lactide)/poly(ethylene glycol)/organo-modified montmorillonite nanocomposites via melt intercalation under continuous elongation flow

2018 ◽  
Vol 38 (5) ◽  
pp. 449-460 ◽  
Author(s):  
Ting Wu ◽  
Ding Yuan ◽  
Jin-Ping Qu
Keyword(s):  
Thermal Stability ◽  
Ethylene Glycol ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Nucleation Density ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
Modified Montmorillonite ◽  
Elongation Flow ◽  
Poly Ethylene

AbstractAn innovative eccentric rotor extruder (ERE), which can generate continuous elongation flow, was used to prepare the poly(L-lactide) (PLLA)/poly(ethylene glycol) (PEG)/organo-modified montmorillonite (OMMT) nanocomposites. The morphology was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and showed that the OMMT nanoparticles were uniformly dispersed in the matrix and mainly existed in intercalation mode. The influence of OMMT on the rheological behavior of plasticized PLLA was investigated by dynamic rheological measurements, showing greater improvement of rheological properties compared to that of PLLA/PEG blend. The crystallization behavior and crystalline structures were studied by differential scanning calorimetry (DSC) and XRD, respectively, and showed that the presence of OMMT further speeds up the crystallization rate of plasticized PLLA. However, the crystallization rate and crystallinity had a slight downward trend at high OMMT content because of the inhibition effect of the OMMT percolation network structure. Polarizing optical microscopy (POM) was further carried out and proved that the OMMT nanoparticles as a heterogeneous nucleating agent can increase the spherulite growth rate and nucleation density. The thermal stability was investigated by thermogravimetric analysis and indicated that the addition of OMMT at low concentration can improve the thermal stability of plasticized PLLA more effectively.

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