scholarly journals Fliposomes: pH-controlled Release from Liposomes Containing New trans-2-Morpholinocyclohexanol-based Amphiphiles that Perform a Conformational Flip and Trigger an Instant Cargo Release upon Acidification

2012 ◽  
Vol 7 (3) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Yu Zheng ◽  
Xin Liu ◽  
Nataliya M. Samoshina ◽  
Vyacheslav A. Chertkov ◽  
Andreas H. Franz ◽  
...  
Keyword(s):  
Molecular Size ◽  
Ph Sensitive ◽  
Molar Ratio ◽  
Ph Titration ◽  
Conformational Switch ◽  
Liposome Membrane ◽  
H Nmr ◽  
Rapid Release ◽  
New Type ◽  
Plausible Mechanism

A new type of pH-sensitive liposome (fliposomes) was designed based on the amphiphiles that are able to perform a pH-triggered conformational flip (flipids). This flip disrupts the liposome membrane and causes rapid release of the liposome cargo, specifically in the areas of increased acidity. The flipids (1-3) are equipped with a trans-2-morpholinocyclohexanol conformational switch. pH-Sensitive fliposomes containing one of these flipids, POPC and PEG-ceramide (molar ratio 50/45/5) were constructed and characterized. These compositions were stable at 4oC and pH 7.4 for several months. Fliposomes loaded with ANTS/DPX demonstrated an unusually quick content release (in a few seconds) at pH below 5.5, which was more efficient in the case of flipid 1 with the shorter linear C12-tails. The pH-titration curve for the fliposome leakage paralleled the curve for the acid-induced conformational flip of 1-3 studied by 1H NMR. A plausible mechanism of the pH-sensitivity starts with an acid-triggered conformational flip of 1, 2 or 3, which changes the molecular size and shape, shortens the lipid tails, and perturbs the liposome membrane resulting in the content leakage.

Synthesis and Characterization of Block Copolymer from Natural Rubber, Toluene-2,4-Diisocyanate and Poly(ξ-aprolactone) Diol-Based Polyurethane

2011 ◽  
Vol 695 ◽  
pp. 316-319 ◽  
Author(s):  
Wannarat Panwiriyarat ◽  
Varaporn Tanrattanakul ◽  
Jean François Pilard ◽  
Chuanpit Khaokong
Keyword(s):  
Block Copolymer ◽  
Natural Rubber ◽  
Soft Segment ◽  
Molar Ratio ◽  
H Nmr ◽  
Chain Cleavage ◽  
Epoxidation Reaction ◽  
Liquid Natural Rubber ◽  
New Type

A new type of polyurethane (PU) has been synthesized by using hydroxyl terminated liquid natural rubber (HTNR) and poly(e-caprolactone) (PCL) as a soft segment and toluene-2,4 diisocyanate (TDI) as a hard segment. This PU becomes a biodegradable and recyclable polymer. The PU samples were synthesized by solution polymerization. TDI/PCL polymerization was prepared in order to determine the appropriate NCO:OH ratio which evaluated from the molecular weight of derived PU and the ratios which were able to form a polymeric film. The suitable NCO:OH ratios were 0.84:1 – 1.20:1 and the Mn of the derived PUs was 3000-5500 g/mol determined by using GPC. PU from PCL-HTNR block copolymer was synthesized by varying molar ratio between PCL and HTNR. HTNR has been synthesized by epoxidation reaction and chain cleavage of natural rubber. The Mn of HTNR was in the range of 1700-8000 g/mol. 1H-NMR and FTIR were used to determine the functional group in order to verify the prepared HTNR and PU. Glass transition temperature and thermal decomposition of PU samples were investigated by using DSC and TGA, respectively.

New type of addition to 5-substituted 4-arylidene-2-(4,5-dihydrofurfurylidene)-N,N-dimethyliminium bisperchlorates. Preparation of 4-substituted 5-(N,N-dimethylamino)-2-furancarbaldehydes

1986 ◽  
Vol 51 (3) ◽  
pp. 573-580 ◽  
Author(s):  
Tibor Gracza ◽  
Zdeněk Arnold ◽  
Jaroslav Kováč
Keyword(s):  
Nmr Spectra ◽  
Addition Reaction ◽  
H Nmr ◽  
Organic Bases ◽  
New Type

4-Arilidene-5-(N,N-dimethyliminium)-2-(4,5-dihydrofurfurylidene)-N,N-dimethyliminium bisperchlorate I undergoes a 1,4-addition reaction with organic bases under re-formation of the furan nucleus; this behaviour has been utilized in the preparation of new 4-substituted 5-(N,N-dimethylamino)-2-furancarbaldehydes II, III. The structure of the prepared compounds has been confirmed by 13C and 1H NMR spectra.

scholarly journals Synthesis, Characterization, and Electrochemical Behaviour of Cobalt(II) and Nickel(II) Complexes with N2O2 Chelating Ligand 4,4′-(Biphenyl-4,4′-diyldinitrilo)dipentan-2-one

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Lakhdar Sibous ◽  
Embarek Bentouhami ◽  
Mustayeen Ahmed Khan
Keyword(s):  
Schiff Base ◽  
Mass Spectroscopy ◽  
Elemental Analysis ◽  
Electrochemical Behaviour ◽  
Absolute Ethanol ◽  
Molar Ratio ◽  
H Nmr ◽  
Chelating Ligand ◽  
Metal Ligand

4,4′-Diaminobiphenyl reacts with 2,4-pentanedione in absolute ethanol in a molar ratio 1 : 2 to form mainly the product of [1 + 2] condensation, 4,4′-(biphenyl-4,4′-diyldinitrilo)dipentan-2-one (H2L). The Schiff base was used as tetradentate chelating ligand to coordinate CoII and NiII chlorides leading to complexes where the ratio of metal ligand was found to be 2 : 1 or 2 : 2. All the synthesized products were characterized by elemental analysis, infrared, electronic, and mass spectroscopy, 1H NMR, and DSC. The electrochemical behaviour of the ligand and its complexes in DMF is also investigated.

scholarly journals Friedel-Crafts Polyketones: Synthesis, Characterization and Antimicrobial Properties of Unsaturated Polyketones and Copolyketones Based on Difurfurylidene Cycloheptanone

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Nayef S. Al-Muaikel
Keyword(s):  
Model Compound ◽  
Antimicrobial Properties ◽  
Morphological Properties ◽  
H Nmr ◽  
Dsc Measurements ◽  
Protic Solvents ◽  
Elemental Analyses ◽  
New Type ◽  
Antibacterial And Antifungal ◽  
Tga And Dsc

A new type of unsaturated polyketones and copolyketones having cycloheptanone moiety in a p-conjugated main chain were synthesized via Friedel-Crafts reaction through the polymerization of the monomer: 2,7-bis furfurylidene cycloheptanoneIwith different diacid chlorides. The model compound was synthesized by reactingIwith benzoyl chloride and characterized by1H-NMR, IR, and elemental analyses. The polyketones and copolyketones were soluble easily in protic solvents like H2SO4and trifluoroacetic acid. The thermal properties of these polyketones and copolyketones were evaluated and correlated to their structural units by TGA and DSC measurements. The crystallinity of some polymers was tested by X-ray analyses; also the morphological properties of selected examples of poly and copolyketones were detected by SEM. All the polyketones were tested for their biological activity against bacteria, fungi, and yeast. It was observed that the majority of the polyketones and its copolymers synthesized can be used as antibacterial and antifungal agents.

DEVELOPMENT OF A SPECIFIC RADIODMMUNOASSAY FOR DETERMINATION OF PEPTIDES DERIVED FROM HUMAN LEUKOCYTE ELASTASE DEGRADATION OF HUMAN FIBRIN (OGEN)

1987 ◽  
Author(s):  
R Wallin ◽  
T Saldeen
Keyword(s):  
Human Leukocyte ◽  
In Vitro Study ◽  
Molecular Size ◽  
Molar Ratio ◽  
Leukocyte Elastase ◽  
Severe Renal Failure ◽  
Human Leukocyte Elastase ◽  
Edta Plasma

This paper describes a RIA for determination of the vasoactive peptide BB 30-43 and related peptides derived from leukocyte elastase degradaticn of human fibrin(ogen). The peptide was synthesized and could easily be labelled with 125I.Rabbits were iirmunized with BB 30-43 conjugated to bovine albumin. The antibody was found to bind about 5C% of the tracer in absence of BB 30-43 in a ˜1/800 diluticn. The RIA can detect peptide concentrations between 50 - 25000 pmol/L. The crossreaction with fibrinogen is very low (<0.001%) and with plas-min derived fibrin(ogen) peptides Bβ 1-42 and BB 15-42 also low (<0.2%). Plasma samples can be analyzed without any pretreatment. In an in vitro study fibrin and fibrincgen was degraded with plasmin or leukocyte elastase. Plasmin degradaticn of fibrin and fibrincgen did not release peptides which cross-reacted with our antibody, whereas leukocyte elastase degradation released peptides from both fibrin and fibrinogen which crossreact whith the antibody.The imnunolqgical activity was not changed after degrading peptide Bβ 30-43 with a) trypsin, b) plasmin, c) batraxobin, d) thrombin, e) elastase, at +37°,1 h, in a molar ratio of 1:100. Even degradaticn by elastase (1:3.5) +37°, 1 h, did not destroy the iirmunological activity.The imriunolcgical stability of peptide B< 30-43 in EDTA-plasma (+37°) seems to be very good. In citrated and heparinized plasma the activity of this peptide seems to vanish quite fast. In spite of these results we have detected high levels of iirmunolcgical activitiy in citrated or heparinized patient plasma. The molecular distribution of the peptides detected in plasma by our RIA corresponded to a fragnent containing about 25 amino acids. This fragnent seemes to be rather stable in plasma. When this fragnent was degraded with elastase in vitro a peptide with a molecular size resembling BB 30-43 was obtained. Over 300 patient samples have been studied. About 20 per cent were positive and the highest levels were found in patients with ARDS, septicaemia, severe renal failure, pulmonary embolism, pneumonia and pulmonary congestion.

Phosphor- und Schwefelhydrazin-Verbindungen / Phosphorus- and Sulfurhydrazine-Compounds

1971 ◽  
Vol 26 (12) ◽  
pp. 1232-1235 ◽  
Author(s):  
Herbert W. Roesky ◽  
Olaf Petersen
Keyword(s):  
Ir Spectra ◽  
Elemental Analysis ◽  
Mass Spectra ◽  
Molar Ratio ◽  
H Nmr ◽  
Chemical Behaviour

Pyrosulfonyldifluoride reacts with waterfree hydrazine in a molar ratio of 2 : 3 to give hydrazine -1,2-bis(sulfonylfluoride) in a low yield.. The reaction of N-fluorosulfonylamide and SOCl2 yields NH4⊕⊖ N(SO2F)2. This salt is converted to (C6H5)4P⊕⊖N(SO2F)2 in water by (C6H5)4PCl. (CH3)2NNH2 reacts with PSF3, PSF2Br, PSF2CH3 or PSF2C2H5 to yield the following compounds: (CH3)2NNHPSF2, (CH3)2NN (PSF2)2, (CH3)2NNHPSFCH3 and (CH3)2NNHPSFC2H5. The properties and the chemical behaviour of these substances are described. Results of ir-spectra, as well as 31P-, 19F- and 1H-nmr- and mass-spectra and elemental analysis characterize the compounds.

Preparation and Research of Skeletal Pt-C Compounds

2018 ◽  
Vol 937 ◽  
pp. 83-87 ◽  
Author(s):  
Xin Ling Hu ◽  
Ying Jiang Qian ◽  
Dong Xu Li ◽  
Xiao Min Chen
Keyword(s):  
Optical Properties ◽  
Synthesis Method ◽  
Polymerization Reaction ◽  
Molar Ratio ◽  
Excellent Performance ◽  
Electrical And Optical Properties ◽  
Cermet Material ◽  
New Synthesis ◽  
New Ideas ◽  
New Type

Platinum matrix composite is a new type of functional pottery material, which has excellent mechanical, electrical and optical properties. Due to the complexity of the synthesis method and the expensive equipment, the development of cermet material is extremely slow, so that the method to solve the problem is urgently needed. In view of the excellent performance of the Pt-C compounds, by hydrothermal method and high temperature roasting method, a new synthesis method for the composite is proposed using melamine and four platinum chloride at 60 °C by the polymerization reaction with a molar ratio of 20:1. The synthetic of Pt-C compounds provides a new synthesis method and new ideas and at the same time the Pt-C compounds has excellent performance, showing the excellent applications in machining.

Synthesis, Characterization and Performance of Superplasticizer with a Multi-Arm Structure

2015 ◽  
Vol 815 ◽  
pp. 594-600 ◽  
Author(s):  
Xiao Liu ◽  
Zi Ming Wang ◽  
Jie Zhu ◽  
Ming Zhao ◽  
Yun Sheng Zheng
Keyword(s):  
Acrylic Acid ◽  
The Self ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Reaction Products ◽  
Reaction Conditions ◽  
H Nmr ◽  
Polyhydric Alcohols ◽  
Esterification Rate ◽  
And Performance

A novel superplasticizer with a multi-arm structure, i.e., a “core” connected with multiple copolymer “arms”, was synthesized through two steps including an esterification reaction between polyhydric alcohols and acrylic acid and a copolymerization reaction in an aqueous solution among the esterification product, isobutenyl polyethylene glycol and acrylic acid. The reaction conditions were determined, and the results showed that the esterification rate can reach above 95% with a water-carrying agent of 70g, a catalyst/alcohol molar ratio of 0.07, an inhibitor/monomer molar ratio of 0.03, and a reaction time of 7 hrs. The reaction products were characterized by 1H Nuclear Magnetic Resonance (1H NMR) and Fourier Transform infrared spectroscopy (FTIR). It is confirmed to be the multi-arm structure, and the self-synthesized superplasticizer with a multi-arm structure exhibited higher energy efficiency, which was in accordance with its excellent paste fluidity performances and adsorption behavior in cement paste

Synthesis and optical properties of tetrapyrazinoporphyrazine containing phenylene dendron unit as a peripheral substituent

2009 ◽  
Vol 13 (08n09) ◽  
pp. 939-948 ◽  
Author(s):  
Chun Keun Jang ◽  
Jae Yun Jaung
Keyword(s):  
Catalytic Properties ◽  
Diels Alder ◽  
Laser Desorption Ionization ◽  
Visible Spectroscopy ◽  
Ionization Time ◽  
H Nmr ◽  
Flight Mass Spectrometry ◽  
Out Of Plane ◽  
New Type ◽  
Uv Visible

A dendritic shell can create a distinct micro-environment within its core. It also has the advantage of possessing unique photochemical, photophysical, electrochemical, and catalytic properties. Polyphenylene dendrons, which are characterized by their shape-persistent structures and out-of-plane twisted phenyl components, have previously been successfully attached to various functional groups. We have recently developed a convenient method for synthesizing a new type of porphyrazine that contains both flexible (linear) and more rigid (dendritic) groups. The synthesis of this completely aromatic and dendronic structure is unique in that it is based on a [2+4] Diels-Alder cycloaddition of tetraphenylcyclopentadienone to an ethynyl compound, followed by the elimination of carbon monoxide. In this study, tetrapyrazinoporphyrazinato metal and metal-free complexes were prepared by mixing 2,3-dicyano-5-polyphenylpyrazines with magnesium in n-butanol. The synthesized tetrapyrazinoporphyrazines were characterized by UV-visible spectroscopy, MALDI-TOF-MS (matrix-assisted laser desorption/ionization time-of-flight mass) spectrometry, elemental analysis and 1 H NMR spectroscopy.

Synthetic Technology and Performance of a Novel Fatty Alcohol Polyoxyethylene Carboxylate Surfactants

2011 ◽  
Vol 298 ◽  
pp. 163-168 ◽  
Author(s):  
Yuan Yuan Lei ◽  
Guo Zheng ◽  
Yu Sun ◽  
Yong Zhou
Keyword(s):  
Reaction Time ◽  
Optimum Condition ◽  
Sodium Hydroxide ◽  
Fatty Alcohol ◽  
Succinic Anhydride ◽  
Foam Stability ◽  
Raw Materials ◽  
Molar Ratio ◽  
New Type ◽  
And Performance

In this paper, with fatty alcohol polyoxyethylene (AEO9), succinic anhydride (SA) and sodium hydroxide as raw materials, a new type of fatty alcohol polyoxyethylene carboxylate surfactants (SAE9C-Na) was obtained by esterification and neutralizing effect. The influencing factors were researched and its surface properties were studied. The optimum condition of synthesis was determined: molar ratio of alcohol to acid was 1:1.1, reaction temperature was 85°C, reaction time was 60 min, under this condition, the yield could reach up to 95.8%. The results received from this experiment showed that SAE9C-Na had excellent surface activity and foaming and foam stability, whose emulsification and solubility enhancement were improved greatly.

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