Based on the hypoxia prodrug moiety of p-nitrobenzyl, a selective ratiometric fluorescent sensor (RHP) for the detection of microenvironment hypoxia was designed and synthesized. RHP can be selectively activated by bioreductive enzymes (NTR) and results in an evident blue to green fluorescent emission wavelength change in both solution phases and in cell lines, which might be the first fluorescent ratiometric probe for hypoxia in solid tumors.
Herein, two new classes of macrocyclic compounds, terphen[n]arenes (TPns) (n=3–6) and quaterphen[n]arenes (QPns) (n=3–6), were designed and synthesized by a one‐step condensation reaction in relatively high yields. They comprise 2,2′′‐dimethoxy terphenyl and 2,2′′′‐dimethoxy quaterphenyl monomers, respectively, linked by methylene bridges. Given their long and rigid monomers, TPns and QPns have much larger cavities and better self‐assembly properties than classic macrocycles. More interestingly, the cyclic pentamers and hexamers TP5, TP6, QP5, and QP6 formed supramolecular organogels, which were composed of interwoven fibers, nanosheets, or entangled macropore networks formed by multiple face‐to‐face and edge‐to‐face π⋅⋅⋅π stacking interactions. The xerogel materials effectively captured volatile iodine, not only in aqueous media but also in the gaseous state, and could be recycled multiple times without obvious loss in performance.
A new probe based on the Gabriel mechanism was designed and first used for hydrazine detection with high selectivity against other amines in aqueous solution. Importantly, the probe could be used for gas-state discrimination of hydrazine with different concentrations. Additionally, probe could also be applied for the imaging of hydrazine in living cells.
Reported here is the highly efficient separation of industrially important cis-and trans-1,2-dichloroethene (cis-DCE and trans-DCE) isomers by activated crystalline 2,2',4,4'tetramethoxyl biphen[3]arene (MeBP3) materials,M eBP3a. MeBP3 can be synthesized in excellent yield (99 %), and ac yclic pentamer is also obtained when using 1,2-dichloroethane as the solvent. The structure of MeBP3 in the CH 3 CN@MeBP3 crystal displays at riangle-shape topology, forming 1D channels through window-to-windowp acking. Desolvated crystalline MeBP3 materials,M eBP3a,p referentially adsorb cis-DCE vapors over its trans isomer.MeBP3a is able to separate cis-DCE from a5 0:50 (v/v) cis/trans-isomer mixture,y ielding cis-DCE with ap urity of 96.4 %i nas ingle adsorption cycle.S ingle-crystal structures and powder X-ray diffraction patterns indicate that the uptake of cis-DCE triggers as olid-state structural transformation of MeBP3, suggesting the adaptivity of MeBP3a materials during the sorption process.M oreover,t he separation can be performed over multiple cycles without loss of separation selectivity and capacity.
A novel long-wavelength fluorescence probe has been developed for the detection of nitroreductase (NTR) and hypoxia. could be activated by NTR at 0.1 μM to release the fluorophore and significant changes in fluorescence emission at 658 nm were observed. This feature makes it advantageous for imaging hypoxic cells with minimal endogenous interference.
Polyamines are essential for the growth of eukaryotic cells and can be dysregulated in tumors. Here we describe a strategy to deplete polyamines through host–guest encapsulation using a peptide-pillar[5]arene conjugate (P1P5A, P1 = RGDSK(N
3
)EEEE) as a supramolecular trap. The RGD in the peptide sequence allows the molecule to bind to integrin α
v
β
3
-overexpressing tumor cells. The negative charged glutamic acid residues enhance the inclusion affinities between the pillar[5]arene and cationic polyamines via electrostatic interactions and facilitate the solubility of the conjugate in aqueous media. The trap P1P5A efficiently encapsulates polyamines with association constants of 10
5
–10
6
M
−1
. We show that P1P5A has a wide spectrum of antitumor activities, and induces apoptosis via affecting the polyamine biosynthetic pathway. Experiments in vivo show that P1P5A effectively inhibits the growth of breast adenocarcinoma xenografts in female nude mice. This work reveals an approach for suppressing tumor growth by using supramolecular macrocycles to trap polyamines in tumor cells.
An optical probe based on colorimetric and ratiometric as well as chemiluminometric signal outputs is developed for the specific detection of hydrazine. On the basis of a Gabriel-type reaction, hydrazinolysis of a simple probe CF (4-phtalamide-N-(4'-methylcoumarin) naphthalimide) produces both the fluorescence of 7-amino-4-methylcoumarin with the max emission wavelength changed from 480 to 420 nm (along with a color change from yellow to transparent) and the luminol chemiluminescence activated by H2O2 with a max emission wavelength at 450 nm. The experimental detection limit of hydrazine is 3.2 ppb (0.1 μM). Selectivity experiments proved CF has excellent selectivity to hydrazine over other interfering substances. Probe CF was also successfully applied in the vapor hydrazine detection over other interfering volatile analytes. Furthermore, the probe CF loaded thin-layer chromatography (TLC) plate for vapor hydrazine detection limit is 5.4 mg/m(3) which is well below the half lethal dose of hydrazine gas for mice (LC50(mice), 330 mg/m(3)) and National Institute of Occupational Safety and Health's immediately dangerous to life or health limit (NIOSHIDLH, 66 mg/m(3)). With H2O2, only hydrazinolysis product luminol can be lighted at 450 nm, other species have no signal. Probe CF can also be used for the detection of hydrazine in HeLa cells.
Reported here is a molecule‐Lego synthetic strategy for macrocycles with functional skeletons, involving one‐pot and high‐yielding condensation between bis(2,4‐dimethoxyphenyl)arene monomers and paraformaldehyde. By changing the blocks, variously functional units (naphthalene, pyrene, anthraquinone, porphyrin, etc.) can be conveniently introduced into the backbone of macrocycles. Interestingly, the macrocyclization can be tuned by the geometrical configuration of monomeric blocks. Linear (180°) monomer yield cyclic trimers and pentamers, while V‐shaped (120°, 90° and 60°) monomers tend to form dimers. More significantly, even heterogeneous macrocycles are obtained in moderate yield by co‐oligomerization of different monomers. This series of macrocycles have the potential to be prosperous in the near future.
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