Quenching enhancement of the singlet excited state of pheophorbide-a by DNA in the presence of the quinone carboquone.


:Changes in the emission fluorescence intensity of pheophorbide-a (PHEO) in the presence of carboquone (CARBOQ) were used to obtain the association constant, the number of CARBOQ molecules interacting with PHEO, and the fluorescence quantum yield of the complex. Excitation spectra of mixtures of PHEO and CARBOQ in ethanol (EtOH) show an unresolved doublet in the red-most excitation band of PHEO, indicating the formation of a loose ground-state complex. The 1:1 CARBOQ-PHEO complex shows a higher fluorescence quantum yield in EtOH (0.41 ± 0.02) than in buffer solution (0.089 ± 0.002), which is also higher than that of the PHEO monomer (0.28). Quenching of the PHEO fluorescence by DNA nucleosides and double-stranded oligonucleotides was also observed and the bimolecular quenching rate constants were determined. The quenching rate constant increase as the oxidation potential of the DNA nucleoside increases. Larger quenching constants were obtained in the presence of CARBOQ suggesting that CARBOQ enhances DNA photo-oxidation, presumably by inhibiting the back-electron-transfer reaction from the photoreduced PHEO to the oxidized base. Thus, the enhanced DNA-base photosensitized oxidation by PHEO in the presence of CARBOQ may be related to the large extent by which this quinone covalently binds to DNA, as previously reported.


Photochem Photobiol


Díaz-Espinosa Y,Crespo-Hernández CE,Alegría AE,García C,Arce R




Has Abstract


2011-03-01 00:00:00












  • Photodynamic activity of substituted zinc trisulfophthalocyanines: role of plasma membrane damage.

    abstract::We recently reported that variations in cellular phototoxicity among a series of alkynyl-substituted zinc trisulfophthalocyanines (ZnPcS3Cn) correlates with their hydrophobicity, with the most amphiphilic derivatives showing the highest cell uptake and phototoxicity. In this study we address the role of the plasma mem...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Cauchon N,Nader M,Bkaily G,van Lier JE,Hunting D

    更新日期:2006-11-01 00:00:00

  • Cyclobutane dimers and (6-4) photoproducts in human cells are mended with the same patch sizes.

    abstract::The size of excision repair patches corresponding to excision of (6-4) pyrimidine-pyrimidone photoproducts and (5-5, 6-6) cyclobutane dimers have been independently determined by using bromodeoxyuridine substitution and density increases in isopycnic gradients of small DNA fragments. The two classes of photoproducts w...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Cleaver JE,Jen J,Charles WC,Mitchell DL

    更新日期:1991-09-01 00:00:00

  • Fusion-fission transport of probes and quenchers in microdomains of an amphiphilic ionene polyelectrolyte.

    abstract::In aqueous solution, amphiphilic ionenes such as the [3,22]-ionene spontaneously adopt globular conformations and form microdomains that are highly micelle-like, i.e. are capable of solubilizing organic molecules, binding and exchanging counterions and accelerating or inhibiting the rates of bimolecular reactions. Tim...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Tcacenco CM,Quina FH

    更新日期:2007-05-01 00:00:00

  • Lack of correlation between DNA strand breakage and p53 protein levels in human fibroblast strains exposed to ultraviolet lights.

    abstract::The contribution of DNA strand breaks accumulating in the course of nucleotide excision repair to upregulation of the p53 tumor suppressor protein was investigated in human dermal fibroblast strains after treatment with 254 nm ultraviolet (UV) light. For this purpose, fibroblast cultures were exposed to UV and incubat...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Enns L,Murray D,Mirzayans R

    更新日期:2000-10-01 00:00:00

  • Photosensitization with bacteriochlorins.

    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


    authors: Kessel D,Smith KM,Pandey RK,Shiau FY,Henderson B

    更新日期:1993-08-01 00:00:00

  • A rhodopsin-like protein in the plasma membrane of Silvetia compressa eggs.

    abstract::Unidirectional blue light directs the rhizoid-thallus axis in the apolar zygote of the brown alga, Silvetia compressa. This effect is mediated by an increase in the intracellular concentration of guanosine 3', 5'-cyclic monophosphate. In this study we show the identification of a rhodopsin-like protein, by means of an...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Gualtieri P,Robinson KR

    更新日期:2002-01-01 00:00:00

  • Pluronic F-127: An Efficient Delivery Vehicle for 3-(1'-hexyloxy)ethyl-3-devinylpyropheophorbide-a (HPPH or Photochlor).

    abstract::To determine the impact of delivery vehicles in photosensitizing efficacy of HPPH, a hydrophobic photosensitizer was dissolved in various formulations: 1% Tween 80/5% dextrose, Pluronic P-123 and Pluronic F-127 in 0.5%, 1% and 2% phosphate buffer solutions (PBS). HPPH was also conjugated to Pluronic F-127, and the res...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Cacaccio J,Durrani F,Cheruku RR,Borah B,Ethirajan M,Tabaczynski W,Pera P,Missert JR,Pandey RK

    更新日期:2020-05-01 00:00:00

  • Enhancement of palladium-porphyrin room temperature phosphorescence by alkaline earth metal in deoxycholate aggregates solution.

    abstract::Room temperature phosphorescence (RTP) of three palladium (Pd)-phorphyrins in air-saturated solution of sodium deoxycholate (NaDC) aggregates was measured. RTP of Pd-meso-tetrakis (4-carboxyphenyl) porphyrin (Pd-TCPP) was obviously enhanced in NaDC-aggregates mediated by alkaline earth metal (AEM). Under the same expe...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Wang YT,Wang XW,Zhang Y

    更新日期:2011-07-01 00:00:00

  • Ultraviolet light induces double-strand breaks in DNA of cultured human P3 cells as measured by neutral filter elution.

    abstract::Neutral filter elution at pH 7.2 and 9.6 was used to measure the induction of DNA lesions in human P3 teratocarcinoma cells by monochromatic 254-, 270-, 313-, 334-, 365-, and 405-nm radiation and by 60 gamma rays. In this assay DNA double-strand breaks (dsb) increase the rate of elution of DNA from cell lysates on a f...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Peak JG,Peak MJ

    更新日期:1990-08-01 00:00:00

  • Biologically effective doses of sunlight for immune suppression at various latitudes and their relationship to changes in stratospheric ozone.

    abstract::Using information on solar irradiance at different latitudes derived from a radiative transfer model and a detailed in vivo action spectrum for immune suppression in a murine system, we report here calculations of the "biologically effective" irradiance of sunlight for immune suppression. From 40 degrees N to 40 degre...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: De Fabo EC,Noonan FP,Frederick JE

    更新日期:1990-10-01 00:00:00

  • Systemic suppression of the contact hypersensitivity by the products of protoporphyrin IX photooxidation.

    abstract::Photodynamic therapy (PDT) is frequently accompanied by induction of systemic immunosuppression. Photochemical mechanisms underlying this effect are not completely understood. Here, we demonstrate the immunosuppressive activity of photooxidation products of protoporphyrin IX dimethyl ester (PPIX) in a murine model of ...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Kyagova AA,Mansurova GV,Kozir LA,Ponomarev GV,Pavlov VY,Konstantinov IO,Potapenko AY

    更新日期:2005-11-01 00:00:00

  • Biodistribution and pharmacokinetic studies of a porphyrin dimer photosensitizer (Oxdime) by fluorescence imaging and spectroscopy in mice bearing xenograft tumors.

    abstract::Herein, we present a study of the pharmacokinetics and biodistribution of a butadiyne-linked conjugated porphyrin dimer (Oxdime) designed to have high near-infrared (NIR) 2-photon absorption cross-section for photodynamic therapy (PDT). Changes in biodistribution over time were monitored in mice carrying B16-F10 melan...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Khurana M,Ulrich S,Kim A,Moriyama Y,Netchev G,Akens MK,Anderson HL,Wilson BC

    更新日期:2012-11-01 00:00:00

  • Thermal effectiveness of different IR radiators employed in rheumatoid hand therapy as assessed by thermovisual examination.

    abstract::We conducted a thermovisual comparison of mean hand surface temperature changes upon local heating with two different IR sources. Sixty-six patients with rheumatoid arthritis (47 women and 19 men; average age, 56.1 ± 8.6 years) were subjected to topical heat therapy for one hand with either the standard IR radiator (S...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Rutkowski R,Straburzyńska-Lupa A,Korman P,Romanowski W,Gizińska M

    更新日期:2011-11-01 00:00:00

  • Lovastatin potentiates the photocytotoxic effect of photofrin II delivered to HT29 human colonic adenocarcinoma cells by low density lipoprotein.

    abstract::A 24 h preculture of HT29-18 human colonic adenocarcinoma cells with the sterol synthesis inhibitor lovastatin at concentrations of 0.1-0.5 microM markedly increased the photocytotoxic effect of photofrin II delivered to cells by low density lipoproteins. Under the same conditions, LDL binding and photofrin II (PII) u...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Biade S,Mazière JC,Mora L,Santus R,Mazière C,Auclair M,Morlière P,Dubertret L

    更新日期:1993-02-01 00:00:00

  • Characterization of endogenous protoporphyrin IX induced by delta-aminolevulinic acid in resting and activated peripheral blood lymphocytes by four-color flow cytometry.

    abstract::Lymphocytes treated with delta-aminolevulinic acid (ALA) can accumulate the photoactive, fluorescent heme precursor, protoporphyrin IX (PpIX). With visible light illumination, PpIX can be used in photodynamic therapy (ALA-PDT) to kill or functionally alter cells. The aim of this study was to characterize the effects o...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Hryhorenko EA,Rittenhouse-Diakun K,Harvey NS,Morgan J,Stewart CC,Oseroff AR

    更新日期:1998-05-01 00:00:00

  • Influence of phage proteins on formation of specific UV DNA photoproducts in phage T7.

    abstract::Phage T7 can be used as a biological UV dosimeter. Its reading is proportional to the inactivation rate expressed in HT7 units. To understand the influence of phage proteins on the formation of DNA UV photoproducts, cyclobutane pyrimidine dimers (CPD) and (6-4)photoproducts ((6-4)PD) were determined in T7 DNA exposed ...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Fekete A,Vink AA,Gaspar S,Modos K,Berces A,Ronto G,Roza L

    更新日期:1999-05-01 00:00:00

  • Construction and characterization of hybrid luciferases coded by lux genes from Xenorhabdus luminescens and Vibrio fischeri.

    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


    authors: Xi L,Tu SC

    更新日期:1993-04-01 00:00:00

  • Photosensitization with a chlorin-thiobarbiturate conjugate.

    abstract::The photobiologic properties of a chlorin-thiobarbiturate conjugate were examined. In addition to the characteristic 670 nm chlorin absorbance, the conjugate exhibited new absorbance bands at 517 and 743 nm, but these were not a part of the fluorescence emission spectra, nor was fluorescence observed at wavelengths > ...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Kessel D,Morgan A

    更新日期:1994-05-01 00:00:00

  • Quantum efficiencies of the reversible photoreaction of octopus rhodopsin.

    abstract::The classic method of photometric curves for photosensitivity determination has been extended to the case of photoreversible reactions and applied to the octopus rhodopsin --> acid metarhodopsin photoreaction. In such cases, measurements at one irradiation wavelength yield the sum of the photosensitivities of the forw...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Dixon SF,Cooper A

    更新日期:1987-07-01 00:00:00

  • Hypothesis--ultraviolet-B irradiance and vitamin D reduce the risk of viral infections and thus their sequelae, including autoimmune diseases and some cancers.

    abstract::Many viral infections reach clinical significance in winter, when it is cold, relative humidity is lowest and vitamin D production from solar ultraviolet-B irradiation is at its nadir. Several autoimmune diseases, such as multiple sclerosis, type 1 diabetes mellitus and asthma, are linked to viral infections. Vitamin ...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章,评审


    authors: Grant WB

    更新日期:2008-03-01 00:00:00

  • Molecular evolution of the Ca(2+)-binding photoproteins of the Hydrozoa.

    abstract::Alignment of the primary structures of the hydrozoan photoproteins, aequorin, mitrocomin, clytin and obelin showed very strong amino acid sequence identities. The Ca(2+)-binding sites of the proteins were found to be highly conserved. The Ca(2+)-binding sites were also homologous to the Ca(2+)-binding sites of other C...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Tsuji FI,Ohmiya Y,Fagan TF,Toh H,Inouye S

    更新日期:1995-10-01 00:00:00

  • Water and carboxyl group environments in the dehydration blueshift of bacteriorhodopsin.

    abstract::The proton channels of the bacteriorhodopsin (BR) proton pump contain bound water molecules. The channels connect the purple membrane surfaces with the protonated retinal Schiff base at the membrane center. Films of purple membrane equilibrated at low relative humidity display a shift of the 570 nm retinal absorbance ...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Renthal R,Gracia N,Regalado R

    更新日期:2000-11-01 00:00:00

  • Metformin, an antidiabetic agent reduces growth of cutaneous squamous cell carcinoma by targeting mTOR signaling pathway.

    abstract::The biguanide metformin is widely used for the treatment of Type-II diabetes. Its antiproliferative and pro-apoptotic effects in various tumor cells suggest its potential candidacy for cancer chemoprevention. Herein, we report that metformin significantly inhibited human epidermoid A431 tumor xenograft growth in nu/nu...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Chaudhary SC,Kurundkar D,Elmets CA,Kopelovich L,Athar M

    更新日期:2012-09-01 00:00:00

  • Flavin-based Blue-Light photosensors: a photobiophysics update.

    abstract::This review deals with the biophysical aspects of flavin-based photosensors, comprising cryptochromes, LOV (Light, Oxygen and Voltage) and BLUF (Blue Light sensing Using FAD) proteins. Special emphasis is given to structural issues, photocycle quantum yields and energetics, mechanism of the light-triggered reactions, ...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章,评审


    authors: Losi A

    更新日期:2007-11-01 00:00:00

  • A comparative study of the visible light photochemistry of gilvocarcins V and M.

    abstract::Quantum yields for the formation of superoxide ions, O2-., and singlet oxygen, 1O2, were determined during the photolyses of gilvocarcin M (GM) in air-saturated dry dimethylsulfoxide (DMSO) and in 45:55 (vol/vol) DMSO-water mixtures. The quantum yield for the photoreduction of methyl viologen by GM in nitrogen-saturat...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Alegría AE,Zayas L,Guevara N

    更新日期:1995-09-01 00:00:00

  • Optical Spectroscopy as a Method for Skin Cancer Risk Assessment.

    abstract::Skin cancer is the most prevalent cancer, and its assessment remains a challenge for physicians. This study reports the application of an optical sensing method, elastic scattering spectroscopy (ESS), coupled with a classifier that was developed with machine learning, to assist in the discrimination of skin lesions th...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Rodriguez-Diaz E,Manolakos D,Christman H,Bonning MA,Geisse JK,A'Amar OM,Leffell DJ,Bigio IJ

    更新日期:2019-11-01 00:00:00

  • Thermal recovery of iodopsin from photobleaching intermediates.

    abstract::The chloride effect on the photobleaching process of iodopsin, a chicken red-sensitive cone visual pigment, was studied in detail by time-resolved low-temperature spectroscopy at -40 degrees C to -10 degrees C. Decay-associated difference spectra obtained by kinetic analysis using the singular value decomposition meth...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Imamoto Y,Shichida Y

    更新日期:2008-07-01 00:00:00

  • Application of molecular orbital calculations to interpret the chlorophyll spectral forms in pea photosystem II.

    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


    authors: Nishigaki A,Ohshima S,Nakayama K,Okada M,Nagashima U

    更新日期:2001-03-01 00:00:00

  • Separation, identification and determination of luciferin in the Iranian firefly, Lampyris turkestanicus by HPLC and spectroscopic methods.

    abstract::Iranian firefly larvae, Lampyris turkestanicus collected from north of Iran and their luciferin were analyzed by HPLC, TLC, MS and spectroscopic Fourier transform ([FT]-IR, FT-NMR, UV and fluorescence) methods. The results showed that luciferin in L turkestanicus lanterns was the same as in the American firefly, Photi...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Hadj-Mohammadi MR,Chaichi MJ

    更新日期:1996-11-01 00:00:00

  • Supramolecular cationic tetraruthenated porphyrin induces single-strand breaks and 8-oxo-7,8-dihydro-2'-deoxyguanosine formation in DNA in the presence of light.

    abstract::The aim of this investigation is the evaluation of DNA interaction of with tetraruthenated porphyrin (TRP) and of DNA damage in the presence of light. Direct-fluorescence and electronic absorption measurements after incubation of DNA with TRP indicate strong binding between pBR322 DNA or calf thymus DNA with the modif...

    journal_title:Photochemistry and photobiology

    pub_type: 杂志文章


    authors: Onuki J,Ribas AV,Medeiros MH,Araki K,Toma HE,Catalani LH,Di Mascio P

    更新日期:1996-03-01 00:00:00