scholarly journals Calix[4]arene-click-cyclodextrin and supramolecular structures with watersoluble NIPAAM-copolymers bearing adamantyl units: “Rings on ring on chain”

2010 ◽  
Vol 6 ◽  
pp. 784-788 ◽  
Author(s):  
Bernd Garska ◽  
Monir Tabatabai ◽  
Helmut Ritter
Keyword(s):  
Mass Spectrometry ◽  
Light Scattering ◽  
Ir Spectroscopy ◽  
Complex Formation ◽  
Dynamic Light Scattering ◽  
Click Reaction ◽  
Supramolecular Complex ◽  
H Nmr ◽  
Microwave Assisted ◽  
Ph Dependent

We describe the calixarene-cyclodextrin-coupling via click reaction starting from 5,11,17,23-tetra-tert-butyl-25,27-dipropargylether-26,28-hydroxy-calix[4]arene (calix[4]arene-dipropargylether) (2) onto 6I-azido-6I-deoxycyclomaltoheptaose (3) under microwave assisted conditions. The coupling was proven by MALDI-TOF mass spectrometry, 1H NMR and IR-spectroscopy. The pH dependent supramolecular complex formation with poly(NIPAAM) bearing attached adamantyl units was investigated by dynamic light scattering (DLS) and turbidity measurements.

scholarly journals Linkage of α-cyclodextrin-terminated poly(dimethylsiloxanes) by inclusion of quasi bifunctional ferrocene

2013 ◽  
Vol 9 ◽  
pp. 1278-1284 ◽  
Author(s):  
Helmut Ritter ◽  
Berit Knudsen ◽  
Valerij Durnev
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Light Scattering ◽  
Ir Spectroscopy ◽  
Nmr Spectra ◽  
H Nmr ◽  
Scattering Measurements ◽  
End Groups ◽  
2D Roesy ◽  
2D Roesy Nmr

We report the noncovalent linkage of terminally substituted oligo(dimethylsiloxanes) bearing α-cyclodextrins (α-CD) as host end groups for the cyclopentadienyl rings of ferrocene. This double complexation of unsubstituted ferrocene leads to a supramolecuar formation of the siloxane strands. Structural characterization was performed by the use of 1H NMR and IR spectroscopy and by mass spectrometry. Electron microscopy studies and dynamic light scattering measurements show a significant decrease of the derivative size after the complexation with ferrocene. In addition, further evidence for the successful complexation of the end groups was verified by the shifts of the protons in the 1H NMR spectra and in the correlation signals of the 2D ROESY NMR spectra.

scholarly journals Superstructures of fluorescent cyclodextrin via click-reaction

2013 ◽  
Vol 9 ◽  
pp. 827-831 ◽  
Author(s):  
Arkadius Maciollek ◽  
Helmut Ritter ◽  
Rainer Beckert
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Flow Field ◽  
Click Reaction ◽  
Field Flow Fractionation ◽  
Asymmetric Flow ◽  
H Nmr ◽  
Intermolecular Complexes ◽  
Vis Spectroscopy ◽  
Polymeric Structures

Mono-(6-azido-6-deoxy)-β-cyclodextrin (CD) was covalently attached to an alkyne-modified 5-methyl-2-(pyridin-2-yl)thiazol-4-ol yielding a fluorophore containing CD in a click-type reaction. Intermolecular complexes were formed by poly(host–guest)-interactions. The supramolecular structures were characterized by 1H NMR-ROESY spectroscopy, dynamic light scattering, UV–vis spectroscopy, fluorescence spectroscopy, and asymmetric flow field-flow fractionation. By adding potassium adamantane-1-carboxylate, the thiazol dye is displaced from the CD-cavity and the elongated noncovalent polymeric structures collapse.

scholarly journals Fluorinated maleimide-substituted porphyrins and chlorins: synthesis and characterization

2019 ◽  
Vol 15 ◽  
pp. 2704-2709
Author(s):  
Valentina A Ol’shevskaya ◽  
Elena G Kononova ◽  
Andrei V Zaitsev
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Maleic Anhydride ◽  
Click Reaction ◽  
Synthesis And Characterization ◽  
H Nmr

Maleimide-containing fluorinated porphyrins and chlorins were prepared based on the reaction of Zn(II) or Ni(II) complexes of 5,10,15,20-tetrakis(4-amino-2,3,5,6-tetrafluorophenyl)porphyrin and chlorin with maleic anhydride. Porphyrin maleimide derivatives were also prepared by the reaction of 5,10,15,20-tetrakis(4-azido-2,3,5,6-tetrafluorophenyl)porphyrinato Zn(II) or Ni(II) with N-propargylmaleimide via the CuAAC click reaction to afford fluorinated porphyrin–triazole–maleimide conjugates. New maleimide derivatives were isolated in reasonable yields and identified by UV–vis, 1H NMR, 19F NMR spectroscopy and mass-spectrometry.

pH-dependent oligomerization of BPTI in undersaturated and supersaturated solutions studied by dynamic light scattering

2002 ◽  
Vol 237-239 ◽  
pp. 289-294 ◽  
Author(s):  
Shinpei Tanaka ◽  
Mitsuo Ataka ◽  
Kazuo Onuma ◽  
Jean-Pierre Astier ◽  
Stéphane Veesler
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Ph Dependent ◽  
Supersaturated Solutions

The oligomeric state, complex formation, and chaperoning activity of Hsp70 and Hsp80 of Neurospora crassa

2002 ◽  
Vol 80 (6) ◽  
pp. 797-809 ◽  
Author(s):  
M E Britton ◽  
M Kapoor
Keyword(s):  
Surface Plasmon Resonance ◽  
Light Scattering ◽  
Complex Formation ◽  
Dynamic Light Scattering ◽  
Neurospora Crassa ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Molecular Chaperones ◽  
Citrate Synthase ◽  
Oligomeric State

Molecular chaperones perform vital cellular functions under normal growth conditions and protect cells against stress-induced damage. The stress proteins Hsp70 and Hsp80 of Neurospora crassa were extracted from heat-shocked mycelium, purified to near homogeneity, and examined with respect to their oligomeric state, complex formation, and chaperoning properties. Their oligomeric state was assessed by dynamic light-scattering measurements, and both Hsp70 and Hsp80 were observed to form a range of soluble, high-molecular-mass protein aggregates. Direct interaction between Hsp70 and Hsp80 was studied by partial tryptic digestion and surface plasmon resonance (SPR). Hsp70 was immobilized on the sensor chip surface, and the binding of Hsp80 in solution was followed in real time. Proteolytic digestion revealed that Hsp70–Hsp80 complex formation results in conformational changes in both proteins. The data from SPR studies yielded an equilibrium dissociation constant, KD, of 8.5 × 10–9 M. The chaperoning ability of Hsp70, Hsp80, and Hsp70–Hsp80 was monitored in vitro by the protection of citrate synthase from thermal aggregation. The binding of nucleotides modulates the oligomeric state, chaperoning function, and hetero-oligomeric complex formation of Hsp70 and Hsp80.Key words: molecular chaperones, surface plasmon resonance, dynamic light scattering, trypsin digestion, citrate synthase, Neurospora crassa.

A pyridinium modified β-cyclodextrin: an ionic supramolecular ligand for palladium acetate in C–C coupling reactions in water

2016 ◽  
Vol 18 (20) ◽  
pp. 5518-5528 ◽  
Author(s):  
Raihana Imran Khan ◽  
Kasi Pitchumani
Keyword(s):  
Mass Spectrometry ◽  
Light Scattering ◽  
Ir Spectroscopy ◽  
Water Soluble ◽  
Palladium Acetate ◽  
Coupling Reactions ◽  
Visible Spectroscopy ◽  
Ft Ir ◽  
Uv Visible ◽  
Ft Ir Spectroscopy

An ionic Pd(ii) complex stabilized by a water soluble pyridinium modified β-cyclodextrin was prepared and characterized by NMR, mass spectrometry, FT-IR spectroscopy, UV-visible spectroscopy and DLS (dynamic light scattering).

scholarly journals Temperature Responsive Nanoparticles Based on PEGylated Polyaspartamide Derivatives for Drug Delivery

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 316 ◽  
Author(s):  
Guangyan Zhang ◽  
Xulin Jiang
Keyword(s):  
Drug Delivery ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Click Reaction ◽  
Drug Loading ◽  
In Vitro Cytotoxicity ◽  
Chemical Structures ◽  
Temperature Responsive ◽  
Mean Size

The temperature responsive PEGylated polyaspartamide derivative, denoted as mPEG-PAAHP, was synthesized by the click reaction. FTIR and 1H NMR were adopted to characterize and confirm the chemical structures of the obtained mPEG-PAAHPs. The temperature responsive behavior investigated by transmittance and dynamic light scattering showed that some of the obtained mPEG-PAAHPs exhibited obvious temperature responsiveness and could be used to prepare nanoparticles by quickly heating. Drug paclitaxel can be encapsulated into mPEG-PAAHP based nanoparticles with a high encapsulation efficiency up to 99% (corresponding to a drug loading content of around 9.9%). Dynamic light scattering results showed that the PTX-loaded nanoparticles had a mean size around 80 nm (PDI<0.2) and good stability in PBS with 150 mM ionic strength. In vitro cytotoxicity results showed that mPEG-PAAHP did not show any toxicity to HeLa cells, but the PTX-loaded nanoparticles based on mPEG-PAAHP exhibited obvious anti-cancer activity. Thus, the temperature responsive PEGylated polyaspartamide derivative mPEG-PAAHP may be a promising drug delivery system.

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