- Light-driven release of cucurbit[8]uril from a bivalent cage
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Temporal control over supramolecular systems has great potential for the modulation of binding and assembly events, such as providing orthogonal control over protein activity. Especially light controlled triggering provides unique entries for supramolecular systems to interface in a controlled manner with enzymes. Here we report on the light-induced release of cucurbit[8]uril (CB[8]) from a bivalent cage molecule and its subsequent activation of a proteolytic enzyme, caspase-9, that itself is unresponsive to light. Central to the design is the bivalent binding of the cage with high affinity to CB[8], 100-fold stronger than the UV-inactivated products. The affinity switching occurs in the (sub-)micromolar concentration regime, matching the concentration characteristics required for dimerizing and activating caspase-9 by CB[8]. The light-responsive caged CB[8] concept presented offers a novel platform for tuning and application of switchable cucurbiturils and beyond.
- De Vink, Pim J.,Van Der Hek, Tim,Brunsveld, Luc
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- Improved method for the preparation of nonyl acridine orange analogues and utilization in detection of cardiolipin
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This study was designed to develop a fast and convenient methodology for the preparation of 10-nonyl acridine orange (NAO) and its silyl analogues to improve their photo-physical properties for the detection and quantification of cardiolipin (CL). Optimized conditions allow the effective synthesis of NAO analogues with good yield and excellent purity. The introduction of a 3-(trimethylsilyl)propyl moiety improves the dye's solubility and stability in buffer solution and increases its emission intensity by ≈30percent. The novel dye can be used for the selective quantification of CL in a liposomal inner mitochondrial membrane model with greater fluorescence intensity and linear slope compared to NAO. The novel silicon-containing NAO analogue has lower cytotoxicity, and is a convenient fluorescent dye for cell staining. This journal is
- Arsenyan, Pavel,Dimitrijevs, Pavels,Domracheva, Ilona
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p. 9626 - 9633
(2020/07/03)
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- Nitrogen anthracene class compound and its synthetic method and application (by machine translation)
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The invention discloses a formula (2) shown in nitrogen anthracene class of compound and its synthetic method, high Iodized salt as reaction raw material, in the inorganic nitrogen reagent, additive, water, alkali, under the action of the metal catalyst, in the 80 - 150 °C conditions, reacts in a solvent 12 - 60 hours to obtain various nitrogen anthracene class compounds. The invention by post method of introducing nitrogen atoms, to avoid the early stage in the reaction of the nitrogen heterocyclic to metal catalyst of the reaction conditions such as not compatibility; in addition, high Iodized salt in the full utilization of the two aryl, shows that the method of the invention atom economy. Prepared by the method of the invention can be further applied [...] compound of the fluorescent indicator acridine orange synthesis. (by machine translation)
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Paragraph 0123-0126
(2018/05/16)
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- Photo-induced proton-coupled electron transfer reactions of acridine orange: Comprehensive spectral and kinetics analysis
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The triplet excited state of acridine orange (3*AO) undergoes a proton-coupled electron transfer (PCET) reaction with tri-tert-butylphenol (ttbPhOH) in acetonitrile. Each of the reaction components possesses a spectroscopic signature, providing a rare opportunity to monitor the individual proton transfer, electron transfer, and H ?-transfer components in parallel via transient absorption spectroscopy. This enhanced optical tracking, along with excited-state thermochemical analysis, facilitates assignment of the mechanism of excited-state PCET reactivity. 3*AO is quenched via concerted proton-electron transfer (CPET) from ttbPhOH to form acridine radical (AOH?) and ttbPhO? (kCPET = 3.7 × 108 M-1 s-1, KIE = 1.3). Subsequently, AOH? reduces the phenoxyl radical (kET = 5.5 × 109 M-1 s-1), forming AOH + and ttbPhO-, followed by proton transfer (kPT = 1.0 × 109 M-1 s-1) to regenerate the starting reactants.
- Eisenhart, Thomas T.,Dempsey, Jillian L.
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p. 12221 - 12224
(2014/11/08)
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- ACID BASE REACTIONS BETWEEN ACRIDINE ORANGE AND SUBSTITUTED PHENOLS IN BENZONITRILE. PART I. THERMODYNAMICS OF ASSOCIATION AND IONIC EQUILIBRIA.
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Proton transfer reactions of the five substituted phenols 3-Cl-4-nitrophenol CNP, 4-nitrophenol NP, 3-methyl-4-nitrophenol MNP, 4-Cl-3,5-dimethylphenol CMP, and 3,5-dimethylphenol DMP with acridine orange, and the formation of hydrogen bonded complexes AHA** minus of the anions A** minus of CNP, NP, and MNP with the respective phenols AH in benzonitrile solution were investigated by means of absorption spectroscopy. The formation enthalpies of the hydrogen bonded anions AHA** minus are much larger than DELTA H//1, so that DELTA H//2 is mainly determined by this association. On the other hand there is no significant difference between DELTA H//2 and DELTA H//3; thus the hydrogen bond formed between a phenol and a complexed anion AHA** minus is very weak. Substituent effects on the acidity of phenols are about twice as large in benzonitrile as in aqueous solution.
- Suettinger,Strohbusch
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p. 744 - 750
(2007/10/02)
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