25798-61-2Relevant articles and documents
Photochemical release of ATP from "caged ATP" studied by time-resolved infrared spectroscopy
Barth, Andreas,Hauser, Karin,M?ntele, Werner,Corrie, John E. T.,Trentham, David R.
, p. 10311 - 10316 (1995)
Rapid scan Fourier transform infrared (FTIR) spectroscopy and time-resolved single wavelength infrared (IR) spectroscopy have been used to follow the photochemical release of adenosine 5′-triphosphate (ATP) from P3-(1-(2-nitrophenyl)ethyl) adenosine 5′-triphosphate (caged ATP). Vibrational difference spectra for the formation first of the aci-nitro anion intermediate and subsequently of ATP and the byproduct(s) were obtained by rapid scan FTIR spectroscopy in the millisecond-to-second time domain. Vibrational modes of the phosphate groups of ATP and caged ATP in the range 1250-900 cm-1 could be assigned on the basis of triple and single 18O labeling in caged ATP at the terminal phosphate group and at the bridging oxygen between the terminal phosphate and the 1-(2-nitrophenyl)ethyl group, respectively. The rapid formation and subsequent decay of the aci-nitro anion intermediate were monitored by single-wavelength time-resolved IR spectroscopy at 1251 cm-1 (predominantly a PO2- mode of caged ATP and the aci-nitro intermediate). The appearance of the free γ-phosphate group of ATP was monitored at 1119 cm-1 (POs2- mode of ATP). Decay of the aci-nitro anion intermediate and formation of ATP were well fitted by single exponentials to give a mean rate constant of 218 ± 33 s-1 at pH 7 and 22 °C.
Photochemical Reaction Mechanisms of 2-Nitrobenzyl Compounds: Methyl Ethers and Caged ATP
Il'ichev, Yuri V.,Schwoerer, Markus A.,Wirz, Jakob
, p. 4581 - 4595 (2004)
The mechanism of methanol photorelease from 2-nitrobenzyl methyl ether (1) and 1-(2-nitrophenyl)ethyl methyl ether (2), and of ATP release from adenosine-5′-triphosphate-[P3-(1-(2-nitrophenyl)-ethyl)] ester ('caged ATP', 3) was studied in various solvents by laser flash photolysis with UV-vis and IR detection. In addition to the well-known primary aci-nitro transients (A, λmax ≈ 400 nm), two further intermediates preceding the release of methanol, namely the corresponding 1,3-dihydrobenz[c]isoxazol-1-ol derivatives (B) and 2-nitrosobenzyl hemiacetals (C), were identified. The dependencies of the reaction rates of A-C on pH and buffer concentrations in aqueous solution were studied in detail. Substantial revision of previously proposed reaction mechanisms for substrate release from 2-nitrobenzyl protecting groups is required: (a) A novel reaction pathway of the aci-tautomers A prevailing in buffered aqueous solutions, e.g., phosphate buffer with pH 7, was found. (b) The cyclic intermediates B were identified for the first time as the products formed by the decay of the aci-tautomers A in solution. A recently proposed reaction pathway bypassing intermediates B (Corrie et al. J. Am. Chem. Soc., 2003, 125, 8546-8554) is shown not to be operative. (c) Hemiacetals C limit the release rate of both 1 (pH 8) and 2 (pH 10). This observation is in contrast to a recent claim for related 2-nitrobenzyl methyl ethers (Corrie et al.). Our findings are important for potential applications of the 2-nitrobenzyl protecting group in the determination of physiological response times to bioagents ('caged compounds').
Supramolecular photochemistry of encapsulated caged: Ortho -nitrobenzyl triggers
Kamatham, Nareshbabu,Raj, A. Mohan,Givens, Richard S.,Da Silva, José P.,Ramamurthy
, p. 2411 - 2420 (2019/10/21)
ortho-Nitrobenzyl (oNB) triggers have been extensively used to release various molecules of interest. However, the toxicity and reactivity of the spent chromophore, o-nitrosobenzaldehyde, remains an unaddressed difficulty. In this study we have applied the well-established supramolecular photochemical concepts to retain the spent trigger o-nitrosobenzaldehyde within the organic capsule after release of water-soluble acids and alcohols. The sequestering power of organic capsules for spent chromophores during photorelease from ortho-nitrobenzyl esters, ethers and alcohols is demonstrated with several examples.
Photocleavage of o-nitrobenzyl ether derivatives for rapid biomedical release applications
Kim, Moon Suk,Diamond, Scott L.
, p. 4007 - 4010 (2007/10/03)
The externally controlled cleavage of covalently linked prodrugs, proteins, or solid-phase formulation vehicles offers potential advantages for controlled drug or gene delivery. A series of o-nitrobenzyl ester compounds (1-8) were synthesized to allow a systematic study of photolability. The o-nitrobenzyl ester was strictly required for photolability, while imido esters were not photolabile. The degradation kinetics of 1-o-phenylethyl ester was an order of magnitude faster than that of o-nitrobenzyl ester. Tosylate, phosphate, and benzoate derivatives of 1-o-nitrophenylethyl displayed similar photolability (>80% decomposition within 10 min at 3.5 mW/cm2 at 365 nm). O-o-Nitrobenzyl O′,O″-diethyl phosphate displayed the fastest decomposition at photoirradiation condition (3.5 mW/cm2, 365 nm) suitable for biological systems. We report the synthesis and photo-decomposition of 1-o-nitrophenylethyl derivatives amenable for the creation of photolabile prodrugs or formulation particles for drug depots, DNA condensation, or tissue engineering applications.
