6-Nitro-Quinazolin-4(3H)-one Exhibits Photodynamic Effects and Photodegrades Human Melanoma Cell Lines. A Study on the Photoreactivity of Simple Quinazolin-4(3H)-ones.

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

authors： Alegría AE,Zayas L,Guevara N

更新日期：1995-09-01 00:00:00

abstract：:Time-resolved singlet oxygen, O(2)(a(1)Delta(g)), phosphorescence experiments have been performed in single cells upon pulsed laser irradiation of a photosensitizer incorporated into the cell. Data recorded as a function of the partial pressure of ambient oxygen to which the cell is exposed reflect apparent values for...

journal_title：Photochemistry and photobiology

authors： Hatz S,Poulsen L,Ogilby PR

更新日期：2008-09-01 00:00:00

abstract：:Exposure to ultraviolet radiation results in increased levels of intradermal cis-urocanic acid (cUCA) and alters cutaneous immunity by interfering with processing and presentation of antigen by Langerhans cells. Reports on effects of systemic immunotoxicity with 30 day cUCA exposure in laboratory rodents include thymi...

journal_title：Photochemistry and photobiology

authors： Prater MR,Gogal RM Jr,De Fabo EC,Longstreth J,Holladay SD

更新日期：2003-04-01 00:00:00

abstract：:Photodynamic therapy (PDT) appears as a promising alternative in the treatment of breast cancer since it can be highly effective in curing cancer while preserving normal tissue. However, predicting outcomes in PDT still constitutes a great challenge. One of the parameters that are usually empirically determined is the...

journal_title：Photochemistry and photobiology

authors： Dos Santos AF,de Almeida DRQ,Terra LF,Wailemann RAM,Gomes VM,Arini GS,Ravagnani FG,Baptista MS,Labriola L

更新日期：2020-05-01 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

authors： Senge MO,Smith KM

更新日期：1994-08-01 00:00:00

abstract：:Topical photodynamic therapy is used for a variety of malignant and pre-malignant skin disorders, including Bowen's Disease and Superficial Basal Cell Carcinoma. A haem precursor, typically 5-aminolevulinic acid (ALA), acting as a prodrug, is absorbed and converted by the haem biosynthetic pathway to photoactive proto...

journal_title：Photochemistry and photobiology

authors： Donnelly RF,McCarron PA,Woolfson AD

更新日期：2005-07-01 00:00:00

abstract：:Photodynamic therapy (PDT) of cancer induces oxidative stress, which intervenes in the expression of cytokines by tumor cells. The cytokines might have either a positive or a negative impact on tumor eradication. Here, we studied the expression of cytokines vascular endothelial growth factor (VEGF) and interleukin-1al...

journal_title：Photochemistry and photobiology

authors： Dabkeviciene D,Sasnauskiene A,Leman E,Kvietkauskaite R,Daugelaviciene N,Stankevicius V,Jurgelevicius V,Juodka B,Kirveliene V

更新日期：2012-03-01 00:00:00

abstract：:To determine the origin of the UV-specific CC to TT tandem mutation at the CC site, we made a duplex DNA decamer containing a uracil cis-syn cyclobutane dimer (CBD) as the deaminated model of a cytosine dimer. Two-dimensional 1H-NMR spectroscopy studies were performed on this sequence where two adenines (Ade) were opp...

journal_title：Photochemistry and photobiology

authors： Lee HM,Kim JK

更新日期：2002-10-01 00:00:00

abstract：:Photoproducts in double-stranded DNA induced by 193 nm radiation have been investigated. Double-stranded, supercoiled pBR322 DNA in buffered aqueous solution was exposed to varying fluences of 193 nm radiation from an ArF excimer laser. The quantum yields for formation of cyclobutylpyrimidine dimers, frank strand brea...

journal_title：Photochemistry and photobiology

authors： Kochevar IE,Buckley LA

更新日期：1990-05-01 00:00:00

abstract：:Collagen was exposed to an ultraviolet (UV) lamp that emitted predominantly in the UVB range. The cross-linking of collagen type I and type IV by UV irradiation was observed. Amino acid analyses revealed that Tyr residues in both collagen types I and IV were decreased by irradiation. In collagen type IV, losses of His...

journal_title：Photochemistry and photobiology

authors： Kato Y,Nishikawa T,Kawakishi S

更新日期：1995-04-01 00:00:00

abstract：:Well-resolved vibrational spectra of LH2 complex isolated from two photosynthetic bacteria, Rhodobacter sphaeroides and Ectothiorhodospira sp., were obtained using surface-enhanced resonance Raman scattering (SERRS) exciting into the Qx and the Qy transitions of bacteriochlorophyll a. High-quality SERRS spectra in the...

journal_title：Photochemistry and photobiology

authors： Chumanov G,Picorel R,Ortiz de Zarate I,Cotton TM,Seibert M

更新日期：2000-05-01 00:00:00

abstract：:The interaction with amino acids of the excited states of the N-oxide resazurin and its deoxygenation product resorufin, has been studied in aqueous solution at pH 7.5. Steady-state and time-resolved studies show that the fluorescence is quenched by amino acids. Complexation of the dyes in the ground state with aromat...

journal_title：Photochemistry and photobiology

authors： Villegas ML,Bertolotti SG,Previtali CM,Encinas MV

更新日期：2005-07-01 00:00:00

abstract：:The production of vitamin D3 is a pharmaceutically relevant process, producing high added-value products. Precursors are extracts from vegetal origin but bearing mainly an E geometry in the 5,6 double bond. The synthesis of vitamin D3 (5-E-α-calcidol) with the correct Z stereochemistry in the 5,6 double bond from the ...

journal_title：Photochemistry and photobiology

authors： Estruch GA,Aramendía PF

更新日期：2012-07-01 00:00:00

abstract：:Ultraviolet radiation can inhibit immune responses locally as well as systemically. Such effects have been measured in animals and humans exposed to ultraviolet B (wavelength 280-315 nm) (UVB) and ultraviolet A (315-400 nm) (UVA). The precise wavelength dependence is important for the identification of possible molecu...

journal_title：Photochemistry and photobiology

authors： Garssen J,de Gruijl F,Mol D,de Klerk A,Roholl P,Van Loveren H

更新日期：2001-04-01 00:00:00

abstract：:N2-hydroxyisocytosine and 1-methyl-N2-hydroxyisocytosine were studied using a matrix isolation technique combined with infrared absorption spectroscopy. For N2-hydroxyisocytosine isolated in an Ar matrix (at 10 K), two imino-oxo isomers, one with the hydroxyimino =N-OH group directed toward the N1-H group (the form ca...

journal_title：Photochemistry and photobiology

authors： Lapinski L,Nowak MJ,Kwiatkowski JS,Leszczynski J

更新日期：2003-03-01 00:00:00

abstract：:The decay processes of the lowest excited singlet and triplet states of five heteropsoralens (HPS) were investigated by steady-state and shift-phase fluorometry and by laser-flash photolysis in different solvents. The emission spectra of HPS are detectable only in trifluoroethanol (TFE), where fluorescence lifetimes (...

journal_title：Photochemistry and photobiology

authors： Aloisi GG,Elisei F,Moro S,Miolo G,Dall'Acqua F

更新日期：2000-05-01 00:00:00

abstract：:A polyclonal, multispecific antiserum was raised against a whole 3[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate-extract of nonirradiated Blepharisma japonicum cells. It was used to reveal the composition of solutions that were hypothesized to contain the photoreceptor of the ciliate. A Bio-Gel A 1.5 m fine ...

journal_title：Photochemistry and photobiology

authors： Podestà A,Gioffré D,Grossi T,Montagnoli G

更新日期：2000-05-01 00:00:00

abstract：:We investigated the hypothesis that the strength of the activation of the intra-S DNA damage checkpoint varies within the S phase. Synchronized diploid human fibroblasts were exposed to either 0 or 2.5 J m(-2) UVC in early, mid- and late-S phase. The endpoints measured were the following: (1) radio-resistant DNA synth...

journal_title：Photochemistry and photobiology

authors： Chastain PD 2nd,Brylawski BP,Zhou YC,Rao S,Chu H,Ibrahim JG,Kaufmann WK,Cordeiro-Stone M

更新日期：2015-01-01 00:00:00

abstract：:Photosensitizer (PS)-antibody conjugates (photoimmunoconjugates, PICs) enable cancer cell-targeted photodynamic therapy (PDT). Nonspecific chemical bioconjugation is widely used to synthesize PICs but gives rise to several shortcomings. The conjugates are heterogeneous, and the process is not easily reproducible. More...

journal_title：Photochemistry and photobiology

authors： Sadiki A,Kercher EM,Lu H,Lang RT,Spring BQ,Zhou ZS

更新日期：2020-05-01 00:00:00

abstract：:The interaction between human alpha1-acid glycoprotein (orosomucoid) and the fluorescent probe, 2-p-toluidinylnaphthalene-6-sulfonate (TNS) has been studied. An association constant of 16.7 (+/- 3) x 10(3) M-1 was obtained for the complex at 20 degrees C with a stoichiometry of 1:1. From the effect of temperature on t...

journal_title：Photochemistry and photobiology

authors： Albani J,Vos R,Willaert K,Engelborghs Y

更新日期：1995-07-01 00:00:00

abstract：:Analysis of phosphorescence lifetimes using the Stern-Volmer equation is a reliable means of determining quencher concentration for a uniform sample. Methods of analysis for heterogeneous systems are based on the assumption that the excitation is produced by a momentary flash. This condition is an idealization because...

journal_title：Photochemistry and photobiology

authors： Golub AS,Popel AS,Zheng L,Pittman RN

更新日期：1999-06-01 00:00:00

abstract：:Quantum yields of firefly bioluminescence reactions were determined for beetle luciferases from the three main families of luminous beetles emitting different bioluminescence colors. Quantum yield (QY) was significantly correlated with luminescence spectrum. The green light-emitting luciferase of the Brazilian click b...

journal_title：Photochemistry and photobiology

authors： Niwa K,Ichino Y,Kumata S,Nakajima Y,Hiraishi Y,Kato D,Viviani VR,Ohmiya Y

更新日期：2010-09-01 00:00:00

abstract：:To clarify the role of the Golgi apparatus in photodynamic therapy-induced apoptosis, its signaling pathway was studied after photodynamic treatment of human cervix carcinoma cell line HeLa, in which a photosensitizer, 2,4,5,7-tetrabromorhodamine 123 bromide (TBR), was incorporated into the Golgi apparatus. Laser scan...

journal_title：Photochemistry and photobiology

authors： Ogata M,Inanami O,Nakajima M,Nakajima T,Hiraoka W,Kuwabara M

更新日期：2003-09-01 00:00:00

abstract：:The octahedral rhodium complex, cis-dichloro bis(1,10 phenanthroline)rhodium(III) chloride (BISPHEN), is known to form covalent linkages with DNA involving the attachment of the metal to a base. In order to determine the sequence selectivity of this chemistry, solutions of the complex containing one of the double-stra...

journal_title：Photochemistry and photobiology

authors： Morrison H,Harmon H

更新日期：2000-12-01 00:00:00

abstract：:The nature of the interaction in buffered aqueous solution of several homo and heteroleptic ruthenium(II) polypyridyl complexes containing 2,2'-bipyridine (bpy), 2,2'-bipyrazine (bpz), 1,10-phenanthroline (phen), 4,7-diphenyl-1,10-phenanthroline (dip), 3,4,7,8-tetramethyl-1,10-phenanthroline (tmp), 1,4,5,8-tetraazaphe...

journal_title：Photochemistry and photobiology

authors： Kirsch-De Mesmaeker A,Orellana G,Barton JK,Turro NJ

更新日期：1990-09-01 00:00:00

abstract：:The photodynamic effect of hypericin on EMT6 mouse mammary carcinoma cells was investigated in vitro under aerobic and hypoxic conditions. Under aerobic conditions, hypericin-induced photocytotoxicity was dose dependent within a 1-50 microM range. Under hypoxic conditions, cells were resistant to hypericin-induced pho...

journal_title：Photochemistry and photobiology

authors： Thomas C,Pardini RS

更新日期：1992-06-01 00:00:00

abstract：:Demetalation kinetics of bacteriochlorophylls (BChls) c, d and e from green sulfur photosynthetic bacteria were studied under weakly acidic conditions. Demetalation rate constants of BChl e possessing a formyl group at the 7-position were significantly smaller than those of BChls c and d, which had a methyl group at t...

journal_title：Photochemistry and photobiology

authors： Hirai Y,Tamiaki H,Kashimura S,Saga Y

更新日期：2009-09-01 00:00:00

abstract：:SV40 DNA was irradiated in vitro and in vivo with UV-C (240-280 nm) and UV-B (280-320 nm) light, and damaged sites sensitive to digestion with Escherichia coli endonuclease III (endo III) and bacteriophage T4 endonuclease V (endo V) were quantified. The frequency of endo III-sensitive sites (primarily cytosine photohy...

journal_title：Photochemistry and photobiology

authors： Mitchell DL,Jen J,Cleaver JE

更新日期：1991-11-01 00:00:00

abstract：:Four chemical preservatives commonly used in ophthalmic solutions were tested for their toxic and mutagenic potential in mouse lymphoma cells with and without exposure of the cells to ultraviolet A (UVA) radiation. The preservatives tested were benzalkonium chloride (BAK), chlorhexidine, thimerosal and ethylenediamine...

journal_title：Photochemistry and photobiology

authors： Withrow TJ,Brown NT,Hitchins VM,Strickland AG

更新日期：1989-09-01 00:00:00

abstract：:In this manuscript, we demonstrate the control of film thickness and surface wettability in the photochemical immobilization of poly (vinyl alcohol) (PVA) to a self-assembled monolayer (SAM) containing a phthalimide chromophore. Surface attachment is characterized by ellipsometry and contact angle measurements. The we...

journal_title：Photochemistry and photobiology

authors： Carroll GT,Turro NJ,Mammana A,Koberstein JT

更新日期：2017-10-01 00:00:00