Dithiane, Trithiane, and Dithiazane-Based Photolabile Scaffolds for Molecular Recognition: Mechanism and Efficiency of the Photoinduced Fragmentation in Aqueous Reductive Environments

Kutateladze, Andrei G.; Kottani, Rudresha; Kurchan, Alexei N.; Majjigapu, Janaki R. R.; Shirk, Samuel M.

doi:10.1080/10426500590912673

Cited by 2 publications

(6 citation statements)

References 9 publications

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“…449 9 H -Thioxanthen-9-one has also been introduced as a sensitizer in the dithiane-, trithiane-, and dithiazane-based photolabile scaffolds. 450 …”

Section: Sensitized Releasementioning

confidence: 99%

“…449 9H-Thioxanthen-9-one has also been introduced as a sensitizer in the dithiane-, trithiane-, and dithiazane-based photolabile scaffolds. 450 The dithiane-based linkers were explored for various applications, such as photolabile phospholipids and amphiphiles, 451 calixarene-based rosette, 452 or barbiturate receptors. 453 Dithiane-spiro-crown ethers (e.g., 264; Scheme 125) were used as photolabile moieties, which allowed photochemical interruption of transport through liquid membranes, 448a or as photolabile linkers.…”

Section: Sensitized Release: Photoinduced Electron Transfermentioning

confidence: 99%

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Photoremovable Protecting Groups in Chemistry and Biology: Reaction Mechanisms and Efficacy

et al. 2012

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“…449 9 H -Thioxanthen-9-one has also been introduced as a sensitizer in the dithiane-, trithiane-, and dithiazane-based photolabile scaffolds. 450 …”

Section: Sensitized Releasementioning

confidence: 99%

Section: Sensitized Release: Photoinduced Electron Transfermentioning

confidence: 99%

Photoremovable Protecting Groups in Chemistry and Biology: Reaction Mechanisms and Efficacy

et al. 2012

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“…The size of a particle in 30 mM SDS was estimated to be 8.8 nm by pulse field gradient NMR. The micelle-free dendrimer in DMSO-d 6 has an estimated size of 6.4 nm, which implies that with aqueous detergent one micelle contains one dendrimer molecule. Irradiation, followed by extraction with hexane and GCMS analysis again revealed massrelease of dithiane tags.…”

mentioning

confidence: 99%

“…5 Yet, xanthones are less prone to hydrogen abstraction and survive longer in reducing matrices. 6 The same amplification experiments with small amounts of planted sensitizer were carried out using PAMAM-NH 2 G5 dendrimers. In several experiments, according to sulfur elemental analysis, 86 to 99 of 128 primary amino groups on dendrimer's surface were coupled with the methyldithiane adduct of xanthone-3-carboxylate.…”

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confidence: 99%

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Photoinduced Signal Amplification through Controlled Externally Sensitized Fragmentation in Masked Sensitizers

et al. 2006

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Detection of molecular recognition events has always been an area of primary focus in bioanalytical sciences, with methods based on fluorescence being of preference due to their sensitivity. However, high throughput fluorescence binding assays require the tested ligands to be either spatially addressable or segregated on support beads for mechanical sorting. Solution phase libraries, either unsupported or immobilized on sub-micron carriers, present a challenge, as there were no direct methods to assay them. Our recent methodology for direct screening of solution phase libraries, encoded with photolabile tags, resolves this limitation. 1 It uses dithiane-based molecular systems, capable of photoinduced fragmentation, but only in the presence of external sensitizers, i.e. the fragmentation in such systems is made contingent on a molecular recognition event, which brings the sensitizer in the proximity of the photolabile unit (Scheme 1).The next logical question is whether a molecular recognition event can trigger not just one fragmentation, but rather set off a progression of photochemical events, releasing multiple copies of the encoding dithiane tags, and thus enhancing the sensitivity of detection. In this Communication we prove that such photoamplification can be achieved.Non-PCR amplification of molecular recognition has been implemented via enzymatic catalysis, 2a polymerization, 2b or massive liquid crystal reorientation 2c -all in a spatially addressable fashion. Amplification of electrophoretic tags via sensitized generation of singlet oxygen, with the effect localized due to limited diffusion of 1 O 2 , has also been proposed. 3 Our amplification strategy is fundamentally different. Addition of lithiated dithianes to diaryl ketones -potential sensitizers -disrupts conjugation between the two aromatic moieties, effectively masking the sensitizer. The photosensitized fragmentation in such adducts releases more diaryl ketone, capable of sensitization. In the experiment shown in Figure 1, 3 mol % of 4,4′-dimethoxybenzophenone was added to its dithiane adduct in acetonitrile and irradiated, while UV absorption of the solution was monitored at 360 nm. A typical autocatalytic curve was obtained, indicating that photorelease of the masked ketone accelerated this bimolecular fragmentation. While this process resembles a chain reaction, with the released sensitizer carrying the chain, it is controlled better than radical polymerizations, as the photoamplification chain can be stopped and/or re-initiated at any time by removing or applying the UV source. The amplification uses a source of UV photons to amplify the amount of sensitizer, which often needs to be replenished in photoinduced ET reactions to compensate for irreversible reduction. Another outcome of the amplification is the mass release of dithianes, triggered with a very small amount of the initiator.akutatel@du.edu. Supporting Information AvailableExperimental procedures and spectra. This material is available free of charge via the Internet at http://p...

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Dithiane, Trithiane, and Dithiazane-Based Photolabile Scaffolds for Molecular Recognition: Mechanism and Efficiency of the Photoinduced Fragmentation in Aqueous Reductive Environments

Cited by 2 publications

References 9 publications

Photoremovable Protecting Groups in Chemistry and Biology: Reaction Mechanisms and Efficacy

Photoremovable Protecting Groups in Chemistry and Biology: Reaction Mechanisms and Efficacy

Photoinduced Signal Amplification through Controlled Externally Sensitized Fragmentation in Masked Sensitizers

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