Abstract:
:The photophysical properties of two energy-transfer dyads that are potential candidates for near-infrared (NIR) imaging probes are investigated as a function of solvent polarity. The dyads (FbC-FbB and ZnC-FbB) contain either a free base (Fb) or zinc (Zn) chlorin (C) as the energy donor and a free base bacteriochlorin (B) as the energy acceptor. The dyads were studied in toluene, chlorobenzene, 1,2-dichlorobenzene, acetone, acetonitrile and dimethylsulfoxide (DMSO). In both dyads, energy transfer from the chlorin to bacteriochlorin occurs with a rate constant of approximately (5-10 ps)(-1) and a yield of >99% in nonpolar and polar media. In toluene, the fluorescence yields (Phif=0.19) and singlet excited-state lifetimes (tau approximately 5.5 ns) are comparable to those of the benchmark bacteriochlorin. The fluorescence yield and excited-state lifetime decrease as the solvent polarity increases, with quenching by intramolecular electron (or hole) transfer being greater for FbC-FbB than for ZnC-FbB in a given solvent. For example, the Phif and tau values for FbC-FbB in acetone are 0.055 and 1.5 ns and in DMSO are 0.019 and 0.28 ns, whereas those for ZnC-FbB in acetone are 0.12 and 4.5 ns and in DMSO are 0.072 and 2.4 ns. The difference in fluorescence properties of the two dyads in a given polar solvent is due to the relative energies of the lowest energy charge-transfer states, as assessed by ground-state redox potentials and supported by molecular-orbital energies derived from density functional theory calculations. Controlling the extent of excited-state quenching in polar media will allow the favorable photophysical properties of the chlorin-bacteriochlorin dyads to be exploited in vivo. These properties include very large Stokes shifts (85 nm for FbC-FbB, 110 nm for ZnC-FbB) between the red-region absorption of the chlorin and the NIR fluorescence of the bacteriochlorin (lambdaf=760 nm), long bacteriochlorin excited-state lifetime (approximately 5.5 ns), and narrow ( journal_name journal_title authors doi subject pub_date pages issue eissn issn pii journal_volume pub_type
abstract::Evanescent wave illumination with total internal reflection is often used to provide excitation near a quartz-water interface. We now show that evanescent illumination at one wavelength and incident angle, coupled with light quenching at a second wavelength and incident angle, can be used for selective excitation of f...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.1996.tb03117.x
更新日期:1996-10-01 00:00:00
abstract::5-geranoxypsoralen (Bergamottin) does not photosensitize bacteria or a bacterial virus. It does, however, photosensitize mammalian cells in tissue culture. Irradiation with either black light (300-400 nm) or fluorescent ceiling lights produced at least four photobiologically active degradation products, the chemical n...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.1992.tb04274.x
更新日期:1992-04-01 00:00:00
abstract::Stratospheric ozone depletion has caused an increase in the amount of ultraviolet-B (UV-B) radiation reaching the earth's surface. Numerous investigations have demonstrated that the effect of UV-B enhancements on plants includes reduction in grain yield, alteration in species competition, susceptibility to disease and...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1562/2004-05-03-RA-156.1
更新日期:2004-07-01 00:00:00
abstract::The photochemical reactions of the 1-deaza derivative of riboflavin (RF) have been studied by sub-ps time-resolved fluorescence spectroscopy. A potential effect of the solvent polarity and hydrogen bonding capability on the excited state (ES) dynamics was tested by measuring 1-deaza RF in water and, after acetylation ...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.2009.00646.x
更新日期:2010-01-01 00:00:00
abstract::The in vivo pharmacokinetics of protoporphyrin IX (PpIX) after administration of 5-aminolevulinic acid (ALA) cannot be described accurately by mathematical models using first-order rate processes. We have replaced first-order reaction rates by dose-dependent (Michaelis-Menten [MM]) reaction rates in a mathematical com...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1562/0031-8655(2001)074<0311:ameodd>2.0.co;2
更新日期:2001-08-01 00:00:00
abstract::Comparative study of 13,15-[N-(2-hydroxyethyl)]cycloimide chlorin p6 (2), 13,15-(N-acetoxy)cycloimide chlorin p6 (3), 13,15-(N-hydroxy)cycloimide chlorin p6 methyl ester (4) and 13,15-(N-methoxy)cycloimide chlorin p6 methyl ester (5) together with the previously investigated 13,15-[N-(3-hydroxypropyl)]cycloimide chlor...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1562/0031-8655(2004)079<0172:csoppo>2.0.co;2
更新日期:2004-02-01 00:00:00
abstract::Exposure of human skin to ultraviolet (UV) radiation causes significant damage to that tissue. The effects of UV on the skin mainly include acute inflammation (erythema/edema) and abnormal keratinization wherein prostaglandin E2 (produced by cyclooxygenase-2), interleukin-8 and transglutaminase 1 (a major regulatory f...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章,评审
doi:10.1111/php.13039
更新日期:2019-03-01 00:00:00
abstract::The role of water molecules in spectral tuning of proteins has been left largely unexplored. This topic is important because changing hydrogen bond patterns during the activation process may lead to spectral shifts which can be of diagnostic value for the underlying structures. Arguments put forward in this article ar...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章,评审
doi:10.1111/j.1751-1097.2008.00499.x
更新日期:2009-03-01 00:00:00
abstract::We examined the effects of daily exposure to UVB on growth, reproduction and histological characteristics of Daphnia magna over two generations at 20, 22, 25 and 30°C. Animals were exposed to 16 h of UVA and photosynthetically active radiation daily. Treated animals received 6 h of UVB during the light phase. Parental...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.2012.01197.x
更新日期:2013-01-01 00:00:00
abstract::Reflectance spectrophotometry from 400 to 800 nm on different cutaneous pigmented lesions, including primary and metastatic malignant melanoma, pigmented nevi, lentigo and seborrhoeic keratosis, has been performed by using an external integrating sphere coupled to a spectrophotometer. Measurements show that reflectanc...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.1991.tb08470.x
更新日期:1991-01-01 00:00:00
abstract::Biophysical and photobiological properties of a group of bacteriochlorins were compared with efficacy of these products for photodynamic therapy of murine tumors. Predictive factors for selective photosensitization in vivo include affinity binding to lipoproteins greater than albumin, extinction coefficient at the wav...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.1993.tb09549.x
更新日期:1993-08-01 00:00:00
abstract::The potential for electron transfer quenching of rose bengal triplet (3RB2-) to compete with energy transfer quenching by oxygen was evaluated. Rate constants for oxidative and reductive quenching were measured in buffered aqueous solution, acetonitrile and in small unilamellar liposomes using laser flash photolysis. ...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.1997.tb03133.x
更新日期:1997-07-01 00:00:00
abstract::Photosynthetic bacteria are attractive for biotechnology because they produce no oxygen and so H2 -production is not inhibited by oxygen as occurs in oxygenic photoorganisms. Rhodopseudomonas palustris and Afifella marina containing BChl a can use irradiances from violet near-UV (VNUV) to orange (350-650 nm) light and...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/php.12124
更新日期:2013-09-01 00:00:00
abstract::During the photoreaction cycle of photoactive yellow protein (PYP), a physiologically active intermediate (PYP(M)) is formed as a consequence of global protein conformational change. Previous studies have demonstrated that the photocycle of PYP is regulated by the N-terminal loop region, which is located across the ce...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.2008.00375.x
更新日期:2008-07-01 00:00:00
abstract::The energetic characteristics of selected reaction steps in the bacterial luciferase-catalyzed luminescence reaction were examined by computation using the MNDO-PM3 method. Specifically, a three-step model was proposed to account for the reaction between oxygen and reduced riboflavin 5'-phosphate (1,5H2-FMN) to genera...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:
更新日期:1999-07-01 00:00:00
abstract::The activity of the bimodal fluorescent protein (bmFP) (lambda max, 488 and 517 nm) in the in vitro luciferase reaction has been studied. The bmFP that is produced by Photobacterium phosphoreum strain bmFP is a dimer of two homologous subunits binding four riboflavin 5'-phosphate (FMN)-myristate chromophores. The addi...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1562/0031-8655(2000)071<0237:aotbfp>2.0.co;2
更新日期:2000-02-01 00:00:00
abstract::C-Phycocyanin (PC) trimers associated with linker polypeptides were isolated from the phycobilisome (PBS) rods of Synechococcus sp. PCC 7002. LXY refers to a linker polypeptide (L) having an apparent mass of Y kDa, located at position X in the phycobilisome where X can be R (rod), C (core) or RC (rod-core junction). M...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1562/0031-8655(2001)073<0556:ssotlh>2.0.co;2
更新日期:2001-05-01 00:00:00
abstract::We examined the influence of solar ultraviolet-B radiation (UV-B; 280-320 nm) on the growth, biomass production and phenylpropanoid concentrations of Deschampsia antarctica during the springtime ozone depletion season at Palmer Station, along the Antarctic Peninsula. Treatments involved placing filters on frames over ...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1562/2004-09-18-RA-321
更新日期:2005-09-01 00:00:00
abstract::Molecular cloning techniques were employed to obtain hybrid luciferases with their alpha and beta subunits encoded by luxA and luxB genes, respectively, from Xenorhabdus luminescens strain HW or Vibrio fischeri. Although the two wild-type luminous bacteria are phylogenetically diverged, the hybrid luciferase Xf compri...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.1993.tb02943.x
更新日期:1993-04-01 00:00:00
abstract::The effect of netropsin on the oxidative reactions of duplex DNA was examined. One-electron oxidation of DNA creates a radical cation that migrates through duplex DNA and reacts primarily at GG steps. Netropsin is a dication that specifically binds primarily by hydrogen bonding in the minor groove at sites that have f...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1562/0031-8655(2004)080<0456:EONOOO>2.0.CO;2
更新日期:2004-11-01 00:00:00
abstract::Neutrophils stimulated with formyl-methionyl-leucyl-phenylalanine (fMLP) or leukotriene B4 (LTB4) generated kinetically distinctive luminol augmented chemiluminescence (LCL). Inhibitors of .O2- [superoxide-dismutase (SOD) or tiron], H2O2 (catalase), myeloperoxidase, MPO, (NaN3), HOCl (taurine) and .OH (mannitol) hampe...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.1989.tb04099.x
更新日期:1989-02-01 00:00:00
abstract::Cyamemazine (CMZ) is a neuroleptic drug that mediates cutaneous phototoxicity in humans. Here, the photobehavior of CMZ has been examined within α1 -acid glycoproteins, β- and γ-cyclodextrins and SDS micelles. In all these microenvironments, CMZ emission was enhanced and blue-shifted, and its lifetime was longer. Irra...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/php.12303
更新日期:2014-09-01 00:00:00
abstract::The photochemistry of caged compounds of the o-nitrobenzyl type has been investigated thoroughly in the past. However, even recently new side reactions have been discovered. Earlier, we reported [Bley, F., K. Schaper, and H. Görner (2008), Photochem. Photobiol.84 162-171] that we found long-lived triplet states which ...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.2009.00560.x
更新日期:2009-09-01 00:00:00
abstract::Exposure of solutions containing both tryptophan and hydrogen peroxide to a pulsed ( approximately 180 fs) laser beam at 750 nm induces luminescence characteristic of 5-hydroxytryptophan. The results indicate that 3-photon excitation of tryptophan results in photoionization within the focal volume of the laser beam. T...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.2008.00447.x
更新日期:2009-01-01 00:00:00
abstract::Chronic exposure of the gray, short-tailed oppossum, Monodelphis domestica to ultraviolet radiation (UVR) induces mesenchymal tumors of the cornea. High molecular weight DNA samples from 6 UVR-induced corneal tumors were assayed for their ability to transform NIH 3T3 cells to tumorigenicity. NIH 3T3 cells transfected ...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.1992.tb04256.x
更新日期:1992-03-01 00:00:00
abstract::The crystal and molecular structure of the title compound 4 have been determined by single crystal X-ray crystallography. The structure shows the typical S4-ruffled conformation observed for Ni(II) tetrapyrroles. Compared to the structure of the methyl ester of (13(2)-demethoxycarbonyl-pheophorbidato a)nickel(II), 4 s...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.1994.tb05080.x
更新日期:1994-08-01 00:00:00
abstract::The relationship between levels of in vivo accumulated photosensitizer (Photofrin II), photodynamic cell inactivation upon in vitro or in vivo illumination, and changing tumor oxygenation was studied in the radiation-induced fibrosarcoma (RIF) mouse tumor model. In vivo porphyrin uptake by tumor cells was assessed by ...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.1989.tb04110.x
更新日期:1989-03-01 00:00:00
abstract::The photophysical characteristics of two second-generation PDT photosensitizers, tin ethyl etiopurpurin I (SnET2) and tin octaethylbenzochlorin (SnOEBC), have been measured in homogeneous solution and when bound to bovine serum albumin (BSA). The ground state and triplet state absorption spectra have been characterize...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:
更新日期:1998-12-01 00:00:00
abstract::We have demonstrated that it is possible to launch UVC LED light into bacterial contaminated polymer tubes/catheters and disinfect the intraluminal space of these tubes. This can be achieved by UVC treatment of the catheters on a regular basis. Catheters are in the distal end equipped with an exit hole for administrat...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1111/j.1751-1097.2011.00887.x
更新日期:2011-03-01 00:00:00
abstract::The energy and oscillator strength of electronic transitions of chlorophyll (Chl)-amino acid complexes were calculated by using molecular orbital methods. The energies varied widely with coordinated amino acids and the difference between the maximum and minimum energy was about 830 cm-1. This energy difference was com...
journal_title:Photochemistry and photobiology
pub_type: 杂志文章
doi:10.1562/0031-8655(2001)073<0245:aomoct>2.0.co;2
更新日期:2001-03-01 00:00:00