Premium
PHOTOREACTION OF 5‐METHOXYPSORALEN WITH THYMIDINE and THE THYMINE MOIETY OF ISOLATED and Saccharomyces cerevisiae DNA. CHARACTERIZATION and MEASUREMENT OF THE TWO cis‐syn FURAN‐SIDE MONOCYCLOADDUCTS
Author(s) -
Anselmino Catherine,
Averbeck Dietrich,
Cadet Jean
Publication year - 1995
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1995.tb02399.x
Subject(s) - chemistry , thymidine , furan , moiety , thymine , diastereomer , fluorescence , dna , high performance liquid chromatography , stereochemistry , saccharomyces cerevisiae , photochemistry , biochemistry , chromatography , organic chemistry , yeast , physics , quantum mechanics
The photoreaction of the furan‐side moiety of 5‐methoxypsoralen (5‐MOP) with thymidine used as a DNA model compound was investigated in the dry state. Under these conditions, two main fluorescent photoadducts were formed and isolated by HPLC. The two modified nucleosides were characterized as the two cis‐syn diastereoisomers of furan‐side monoadducts of 5‐MOP to thymidine on the basis of spectroscopic measurements including UV, fluorescence, 1 H‐NMR and circular dichroism analysis. The identification and quantification of the latter photoproducts within naked DNA exposed to photoexcited 5‐MOP were achieved by enzymatic digestion completed by HPLC separation and fluorescence detection. Similarly, the two cis‐syn furan‐side monoadducts were found to be formed in the DNA of Saccharomyces cerevisiae cells after incubation with 5‐MOP and subsequent exposure to 365 nm at an incident dose of 38.4 kJ m −2 . Under these conditions, the rate of induction of two diastereoisomeric photoadducts was as low as one modification per 10 6 and 2 × 10 5 bases, respectively.