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71.
Mono‐allyloxylated Cucurbit[7]uril Acts as an Unconventional Amphiphile To Form Light‐Responsive Vesicles 下载免费PDF全文
Prof. Dr. Kyeng Min Park Dr. Kangkyun Baek Dr. Young Ho Ko Dr. Annadka Shrinidhi Dr. James Murray Won Hyuk Jang Prof. Dr. Ki Hean Kim Prof. Dr. Jun‐Seok Lee Dr. Jejoong Yoo Sungwan Kim Prof. Dr. Kimoon Kim 《Angewandte Chemie (International ed. in English)》2018,57(12):3132-3136
Serendipitously, mono‐allyloxylated cucurbit[7]uril (AO1CB[7]) was discovered to act as an unconventional amphiphile which self‐assembles into light‐responsive vesicles (AO1CB[7]VC) in water. Although the mono‐allyloxy group, directly tethered on the periphery of CB[7], is much shorter (C4) than the hydrophobic tails of conventional amphiphiles, it played an important role in vesicle formation. Light‐activated transformation of the allyloxy group by conjugation with glutathione was exploited as a remote tool to disrupt the vesicle. The vesicle showed on‐demand release of cargo upon irradiation by a laser, after they were internalized into cancer cells. This result demonstrated the potential of AO1CB[7]VC as a new type of light‐responsive intracellular delivery vehicle for the release of therapeutic cargo, within cells, on demand. 相似文献
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Encapsulation of AGE‐Breaker Alagebrium by Cucurbit[7]uril Improved the Stability of Both Its Carbonyl α‐Hydrogen and Thiazolium C2‐Hydrogen
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Shengke Li Yuan‐Fu Ding Hang Yin Prof. Chunming Wang Dr. David Bardelang Prof. Lian‐Hui Wang Prof. Ruibing Wang 《化学:亚洲杂志》2016,11(21):3126-3133
As determined by both 1H NMR and UV/Vis spectroscopic titration, ESI‐MS, isothermal titration calorimetry, and DFT molecular modeling, advanced glycation end products (AGE) breaker alagebrium (ALA) formed 1:1 guest–host inclusion complexes with cucurbit[7]uril (CB[7]), with a binding affinity, Ka, in the order of magnitude of 105 m ?1, thermodynamically driven by both enthalpy (ΔH=?6.79 kcal mol?1) and entropy (TΔS=1.21 kcal mol?1). For the first time, a dramatic inhibition of keto–enol tautomerism of the carbonyl α‐hydrogen of ALA has been observed, as evidenced by over an order of magnitude decrease of both the first step rate constant, k1, and the second step rate constant, k2, during hydrogen/deuterium exchange in D2O. Meanwhile, as expected, the reactivity of C2‐hydrogen was also inhibited significantly, with an upshift of 2.09 pKa units. This discovery will not only provide an emerging host molecule to modulate keto–enol tautomerism, but also potentially lead to a novel supramolecular formulation of AGE‐breaker ALA for improved stability and therapeutic efficacy. 相似文献
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Viktor Kolman Radek Marek Prof. Dr. Zora Strelcova Petr Kulhanek Dr. Marek Necas Prof. Dr. Jan Svec Vladimir Sindelar Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(28):6926-6931
In this study, we have investigated the supramolecular interaction between series of 1‐alkyl‐3‐methylimidazolium guests with variable alkyl substituent lengths and cucurbit[6]uril (CB6) in the solution and the solid state. Correct interpretation of 1H NMR spectra was a key issue for determining the binding modes of the complexes in solution. Unusual chemical shifts of some protons in the 1H NMR spectra were explained by the polarization of the imidazolium aromatic ring upon the complexation with the host. The formation of 1:1 complex between 1‐ethyl‐3‐methylimidazolium and CB6 is in disagreement with previously reported findings describing an inclusion of two guest molecules in the CB6 cavity. 相似文献
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S. P. Gromov 《Russian Chemical Bulletin》2008,57(7):1325-1350
The review presents the results of the development of an universal approach to the molecular design of light-sensitive and
light-emitting nanosized systems with desired properties based on unsaturated and macrocyclic compounds. Within the same class
of compounds, various nanosized systems were constructed using a limited number of structural fragments. These nanosized systems
are susceptible to all main types of photoprocesses, such as fluorescence, photodissociation, photoisomerization, photocycloaddition,
photoelectrocyclization, excimer formation, charge-transfer complex formation, the formation of the twisted intramolecular
charge-transfer state (TICT state), and the electron transfer. The use of photostructural transformations for controlling
the complexation and mechanical movements in molecular devices and machines is discussed. The prospects of application of
the new strategy are exemplified by the design of the previously unknown types of molecular switches, materials for optical
chemosensors, optical data recording and storage media, photoswitchable molecular devices, and photocontrolled molecular machines.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1299–1323, July, 2008. 相似文献
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To track nuclear dynamic processes by fluorescence imaging, nuclear stains should be highly fluorescent, resistant to photobleaching, and inert to nuclear processes. The nuclear stains of the Hoechst family, such as Hoechst 34580, show bright fluorescence only on groove binding to DNA, and therefore may interfere with visualization of nuclear dynamic processes induced by other stimuli. We study host-guest interactions between Hoechst 34580 and Cucurbit[7]uril (CB7) in aqueous solutions. The formation of CB7-Hoechst 34580 inclusion complexes with stoichiometry of 2:1 in water and 1:1 in phosphate-buffered saline (PBS) solution (pH 7.0) is confirmed by (1)H NMR, absorption spectra, fluorescence spectra, MALDI-TOF MS, and molecular modeling. Compared to Hoechst 34580, the inclusion complex exhibits redshifted absorption, intensified fluorescence, improved photostability, weakened DNA binding affinity, comparable ability to penetrate cell nuclei, and better nuclear-staining capability, and thus a new avenue for the application of cucurbituril in fluorescence imaging is opened. 相似文献
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Enzyme-inspired controlled release of cucurbit[7]uril nanovalves by using magnetic mesoporous silica
The controlled release of drugs by biostimuli is highly desirable under physiological conditions for their potential use in advanced applications. The enzyme-inspired controlled release of cucurbituril nanovalves by using magnetic mesoporous silica nanoparticles (MSNs) in near-neutral aqueous solutions is reported for the first time. The encirclement of cucurbit[7]uril (CB[7]) onto the protonated 1,4-butanediamine stalks tethered to the external surfaces of superparamagnetic Fe(3) O(4) -embedded mesoporous silica particles leads to tight blocking of the nanopores. The supramolecular nanovalves are activated by the enzymatic decarboxylation products of lysine, cadaverine (in the protonated form), which has a high affinity for CB[7], so that the encapsulated guest molecules, calcein, in the nanopores are released into the bulk solution. The release of calcein can be controlled in small portions on command by alternating changes in enzymatic decarboxylation products and CB[7]. The amino acid derived polyamines have long been associated with cell growth and cancers. The guest molecules released from the delivery system of magnetic MSNs can act not only on sensing probes for levels of decarboxylases and polyamines, but also on efficacious drugs to specific tissues and cells for regulation of polyamine synthesis. 相似文献