The action of high-intensity laser u.v. radiation on nucleic acid molecules and their constituents in vitro and in vivo is compared with the results of low-intensity u.v. photolysis and gamma-radiolysis.

Download full-text PDF

Source
http://dx.doi.org/10.1080/09553009014552411DOI Listing

Publication Analysis

Top Keywords

two-quantum photochemistry
4
photochemistry nucleic
4
nucleic acids
4
acids comparison
4
comparison conventional
4
conventional low-intensity
4
low-intensity photochemistry
4
photochemistry radiation
4
radiation chemistry
4
chemistry action
4

Similar Publications

Photoionization versus photoheterolysis of all-trans-retinol. The effects of solvent and laser radiation intensity.

Phys Chem Chem Phys

January 2007

Max-Planck-Institut für Bioanorganische Chemie (formerly Max-Planck-Institut für Strahlenchemie), D-45413, Mülheim, Germany.

The time-resolved formation of the retinyl carbocation from all-trans-retinol and all-trans-retinol acetate was studied by use of picosecond flash photolysis. From both precursors, the retinyl cation is produced by heterolytic C-O bond cleavage in solvents of medium polarity (acetonitrile, tetrahydrofuran, propanol with Reichardt polarity parameter ET(N) approximately 0.5) and high polarity (EtOH, MeOH, TFE, HFIP, ET(N) > 0.

View Article and Find Full Text PDF

Excited singlet state and photoionization of 8-methoxypsoralen. Picosecond transient absorption study.

Photochem Photobiol Sci

October 2002

Max-Planck-lnstitut für Strahlenchemie, D-45413 Mülheim, Germany.

Time-resolved pico- and nanosecond transient absorption measurements of 8-methoxypsoralen (8-MOP) were performed in different solvents at room temperature. The excited singlet state has two strong absorption bands with maxima at 430 and 630-690 nm. The lifetime of the first excited singlet state, tau(s), ranges from <10 ps up to 2.

View Article and Find Full Text PDF

A new approach to the theory of the EPR of spin correlated radical pairs (SCRP) is formulated. It is based on spectral exchange methods as applied to the two-site model and takes into account explicitly both the motion of one quantum (transverse magnetization) and two quantum coherences (polarizations) of SCRPs. This innovation allows for the interpretation of anti phase structure (APS) spectral shape asymmetry and for the transformation of the initially created ST0RPM polarization into the APS spectral pattern.

View Article and Find Full Text PDF

The efficiency of the photomodification of target single-stranded DNA with a decanucleotide derivative of p-azidotetrafluorobenzamide (direct photomodification) and with its complexes with decanucleotide derivatives of pyrene complementary to the adjacent segment of the target (sensitized photomodification) was studied as a function of the wavelength of long-wave UV light. The sensitized photomodification occurs mainly by singlet-singlet energy transfer from pyrene to azide in their complementary complex, which allows a significant increase in the rate and level of photomodification. When irradiation occurred simultaneously in the UV and visible regions (365-580 nm), two-photon triplet-triplet sensitization was revealed for the first time, which leads to a still greater acceleration of the target modification and a change of its site-direction from the G11 to T13 residue.

View Article and Find Full Text PDF

Photochemistry of uridine on high intensity laser UV irradiation.

J Photochem Photobiol B

May 1990

Institute of Spectrocopy, U.S.S.R. Academy of Sciences, Troitzk, Moscow Region.

The method of high performance liquid chromatography was applied to investigate the products of single-quantum and two-quantum photo-reactions which occur when an aqueous solution of uridine is irradiated with high intensity nanosecond and picosecond laser UV pulses. A comparison of the experimental results obtained with theoretical models enables a number of photophysical parameters of the highly excited electronic states of the uridine molecule to be determined.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!