Supramolecular Polymers Associative to Carbon Nanotubes
申请人:Reynolds John R.
公开号:US20080287638A1
公开(公告)日:2008-11-20
A supramolecular polymer and its composite with carbon nanotubes, CNTs, are described. The supramolecular polymer is an ensemble of precursors that independently contain “sticky feet” for non-covalent binding to carbon nanotube surfaces and associative groups. There is at least one of the associative groups covalently bound to each of the precursor and there is at least one covalently connecting moiety connecting associative groups within a precursor or connecting an associative group to a linker to a “sticky foot” in a precursor. When the associative groups are in a dissociative state, the supramolecular polymer precursors and CNTs can be combined to form a dispersion. Upon promotion, the dissociated associative groups in the dispersion can associate to yield a CNT/supramolecular polymer composite.
The ratio of monomer and excimer emissions of a triad 1 with tetrathiafulvalene (TTF) and pyrene units could be reversibly modulated by the different oxidation states of the TTF unit. The working mechanism of this new fluorescence switch was demonstrated to be the collective result of the tunable photoinduced electron transfer and resonance energy transfer processes.
Identification and Development of Biphenyl Substituted Iminosugars as Improved Dual Glucosylceramide Synthase/Neutral Glucosylceramidase Inhibitors
作者:Amar T. Ghisaidoobe、Richard J. B. H. N. van den Berg、Saleem S. Butt、Anneke Strijland、Wilma E. Donker-Koopman、Saskia Scheij、Adrianus M. C. H. van den Nieuwendijk、Gerrit-Jan Koomen、Arnold van Loevezijn、Mark Leemhuis、Tom Wennekes、Mario van der Stelt、Gijsbert A. van der Marel、Constant A. A. van Boeckel、Johannes M. F. G. Aerts、Herman S. Overkleeft
DOI:10.1021/jm501181z
日期:2014.11.13
This work details the evaluation of a number of N-alkylated deoxynojirimycin derivatives on their merits as dual glucosylceramide synthase/neutral glucosylceramidase inhibitors. Building on our previous work, we synthesized a series of d-gluco and l-ido-configured iminosugars N-modified with a variety of hydrophobic functional groups. We found that iminosugars featuring N-pentyloxymethylaryl substituents are considerably more potent inhibitors of glucosylceramide synthase than their aliphatic counterparts. In a next optimization round, we explored a series of biphenyl-substituted iminosugars of both configurations (d-gluco and l-ido) with the aim to introduce structural features known to confer metabolic stability to drug-like molecules. From these series, two sets of molecules emerge as lead series for further profiling. Biphenyl-substituted l-ido-configured deoxynojirimycin derivatives are selective for glucosylceramidase and the nonlysosomal glucosylceramidase, and we consider these as leads for the treatment of neuropathological lysosomal storage disorders. Their d-gluco-counterparts are also potent inhibitors of intestinal glycosidases, and because of this characteristic, we regard these as the prime candidates for type 2 diabetes therapeutics.
Investigations on Nanoparticle−Chromophore and Interchromophore Interactions in Pyrene-Capped Gold Nanoparticles
作者:Binil Itty Ipe、K. George Thomas
DOI:10.1021/jp048321a
日期:2004.9.1
Three pyrene alkanethiol derivatives (P1, P2, and P3) possessing flexible alkyl groups of different lengths were attached to nanoparticles of gold (similar to2-3 nm in size) along with dodecanethiol (Au-P1, Au-P2, and Au-P3). The photophysical properties of these systems were investigated as a function of (i) distance of chromophore from gold core, (ii) concentration of pyrene on gold surface, and (iii) solvent polarity. The structured absorption bands of the pyrene chromophore were significantly perturbed near the surface of gold nanoparticles (Au-P1), indicating a strong ground state interaction between the plasmon electrons of Au nanoparticles and thepi-electron cloud of the chromophore. Such effects were not observed in Au-P2 and Au-P3 systems, in which the linker groups are long enough to prevent any ground state interactions. A gradual increase in the peak intensity ratio of band III/I of the normal fluorescence of pyrene chromophore was found with an increase in length of the spacer group. These results indicate that the local environment close to the surface of the An nanoparticle is more polar compared to the bulk medium. Interchromophoric interactions are limited in the Au-P1 system due to the restriction imposed by the curvature of spherical gold nanoparticle whereas the flexible alkyl chain tethering pyrene in Au-P2/Au-P3 allows free interaction between chromophores. Steady state and time-resolved emission studies indicate that the normal fluorescence and intermolecular excimer formation are the main deactivation channels of the singlet excited state of pyrene linked to An nanoparticles, in nonpolar solvents. In contrast, the competitive electron transfer to the gold nanocore dominates in polar solvents.
[EN] SUPRAMOLECULAR POLYMERS ASSOCIATIVE TO CARBON NANOTUBES<br/>[FR] POLYMÈRES SUPRAMOLÉCULAIRES ASSOCIATIFS ET LEURS COMPOSITES AYANT DES NANOTUBES DE CARBONE
申请人:UNIV FLORIDA
公开号:WO2009023337A2
公开(公告)日:2009-02-19
A supramolecular polymer and its composite with carbon nanotubes, CNTs, are described. The supramolecular polymer is an ensemble of precursors that independently contain 'sticky feet' for non-covalent binding to carbon nanotube surfaces and associative groups. There is at least one of the associative groups covalently bound to each of the precursor and there is at least one covalently connecting moiety connecting associative groups within a precursor or connecting an associative group to a linker to a 'sticky foot' in a precursor. When the associative groups are in a dissociative state, the supramolecular polymer precursors and CNTs can be combined to form a dispersion. Upon promotion, the dissociated associative groups in the dispersion can associate to yield a CNT/supramolecular polymer composite.