INIFTA   05425
INSTITUTO DE INVESTIGACIONES FISICO-QUIMICAS TEORICAS Y APLICADAS
Unidad Ejecutora - UE
artículos
Título:
Thymidine radical formation via one-electron transfer oxidation photoinduced by pterin: Mechanism and products characterization
Autor/es:
CAROLINA LORENTE; ANDRÉS H. THOMAS; CAROLINA LORENTE; MARIANA VIGNONI; ANDRÉS H. THOMAS; ESTHER OLIVEROS; MARIANA VIGNONI; ESTHER OLIVEROS; MARIANA PAULA SERRANO; PATRICIA VICENDO; MARIANA PAULA SERRANO; PATRICIA VICENDO
Revista:
FREE RADICAL BIOLOGY AND MEDICINE
Editorial:
ELSEVIER SCIENCE INC
Referencias:
Lugar: Amsterdam; Año: 2016 vol. 96 p. 418 - 431
ISSN:
0891-5849
Resumen:
UV-A radiation (320-400 nm), recognizedas a class I carcinogen, inducesdamage to the DNA molecule and its components through different mechanisms. Pterinderivatives are involved in various biological functions, including enzymaticprocesses, and it has been demonstrated that oxidized pterins may act asphotosensitizers. In particular, they accumulate in the skin of patientssuffering from vitiligo, a chronic depigmentation disorder. We haveinvestigated the ability of pterin (Ptr), the parent compound of oxidizedpterins, to photosensitize the degradation of the pyrimidine nucleotide thymidine 5?-monophosphate (dTMP)in aqueous solutions under UV-A irradiation. Although thymine is less reactivethan purine nucleobases, our resultsshowed that Ptr is able to photoinduce the degradation of dTMP and that the processis initiated by an electron transfer from the nucleotide to the triplet excitedstate of Ptr. In the presence of molecular oxygen, the photochemical processleads to the oxidation of dTMP, whereas Ptr is not consumed. In the absence ofoxygen, both compounds are consumed to yield a product in which the pterinmoiety is covalently linked to the thymine. This compound retains some of thespectroscopic properties of Ptr, such as absorbance in the UV-A region andfluorescence properties.