UV irradiation of nucleic acids: characterization of photoproducts of thymidylyl-(3'-->5')-2'-deoxy-5-fluorouridine.
The acetone-sensitized irradiation using UV-B (ultraviolet light, 280-320 nm; sunlamps) of thymidylyl(3'-->5')deoxyfluorouridine monophosphate produces two main photoproducts. The distribution of these photoproducts is dependent on the pH of the irradiation solution. At pH 6, the cis-syn cyclobutane-type photodimer is the major product, whereas at high pH (8-10) a photoadduct is the major product. These photoproducts have been identified and structurally characterized by H-1 and C-13 NMR spectroscopy. The photoadduct arises from defluorination of the 5-fluorouracil moiety. The structure of the photoadduct maintains the sugar-phosphate backbone of the starting material (d-TpF), and contains a saturated thymine moiety with an added Thy(C6-hydroxyl) and a Thy(C5)-(C5)Ura covalent bond.
Alderfer
J L
JL
Biophysics Department, Roswell Park Cancer Institute, Buffalo, NY 14263.
Soni
S D
SD
Arakali
A V
AV
Wallace
J C
JC
D002851:Chromatography, High Pressure Liquid; D015226:Dinucleoside Phosphates / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005467:Floxuridine / Q000031:analogs & derivatives* / Q000528:radiation effects; D009682:Magnetic Resonance Spectroscopy; D011740:Pyrimidine Dimers; D014466:Ultraviolet Rays
D015226:Dinucleoside Phosphates; D011740:Pyrimidine Dimers; D005467:Floxuridine; C082163:thymidylyl-(3'-5')-2'-deoxy-5-fluorouridine; C017758:thymidylyl-(3'-5')-thymidine