Cinética y Fotoquímica

GRUPO DE INVESTIGACION EN FOTOQUIMICA Y REACTIVIDAD EN PTERIDINAS.

   Nuestro trabajo se focaliza en el estudio de la fotoquímica y la fotofísica de pteridinas, con énfasis en las propiedades fotosensibilizadoras, producción de especies reactivas de oxígeno y reactividad frente a agentes oxidantes. Las pteridinas están presentes en los sistemas biológicos en múltiples formas y desempeñando variadas funciones que van desde pigmentos hasta cofactores enzimáticos de numerosas reacciones metabólicas.

  Las pteridinas tienen una profusa y sorprendente fotoquímica: bajo irradiación UV-A (320-400 nm), estas biomoléculas pueden fluorescer, sufrir transformaciones químicas tales como oxidaciones y dimerizaciones y generar especies reactivas de oxígeno como el oxígeno singlete (¹O₂).

Coordinador

Dr. Andrés H. Thomas

Colaboradores

Carolina Lorente, Laura Dántola
María Paula Denofrio, Adriana Ipiña Hernández
Mariana P. Serrano, Diana C. Castaño
Beatriz N. Zurbano

Link a la página del grupo

Principales publicaciones del grupo referidas al proyecto
(2007 - 2011)

* “Photodynamic Effects of Pterin on HeLa Cells.”
P. Denofrio, C. Lorente, T. Breitenbach, S. Hatz, F.M. Cabrerizo, A.H. Thomas y P.R. Ogilby
Photochemistry and Photobiology, 87 (4), 862-866 (2011).

* “Emission properties of dihydropterins in aqueous solutions.”
M.P. Serrano, M. Vignoni, M.L. Dántola, E. Oliveros, C. Lorente y A.H. Thomas
Physical Chemistry Chemical Physics, 13 (16), 7419-7425 (2011).

* “Production and quenching of reactive oxygen species by pterin derivatives, an intriguing class of biomolecules.”
E. Oliveros, M.L. Dántola, V. Mariana, A.H. Thomas y C. Lorente
Pure and Applied Chemistry, 83 (4), 801-811 (2011).

* “Photodimerization of 7,8-Dihydroneopterin in aqueous solution under UV-A irradiation.”
M. Vignoni, M.P. Serrano, E. Oliveros y A.H. Thomas
Photochemistry and Photobiology, 87 (1), 51-55 (2011).

* “Oxidation of 2'-deoxyadenosine 5'-monophosphate photoinduced by lumazine.”
M.P. Denofrio, A.H. Thomas y C. Lorente
Journal of Physical Chemistry A, 114 (41), 10944-10950 (2010).

* “Fluorescence quenching by oxygen: "Debunking" a classic rule.”
F.M. Cabrerizo, J. Arnbjerg, M.P. Denofrio, R. Erra-Balsells y P.R. Ogilby
ChemPhysChem, 11 (4), 796-798 (2010).

* “Photochemistry of dihydrobiopterin in aqueous solution.”
M. Vignoni, F.M. Cabrerizo, C. Lorente, C. Claparols, E. Oliveros y A.H. Thomas
Organic and Biomolecular Chemistry, 8 (4), 800-810 (2010).

* “1H NMR characterization of the intermediate formed upon UV-A excitation of biopterin, neopterin and 6-hydroxymethylpterin in O₂-free aqueous solutions.”
M. Vignoni, M.L. Salum, R. Erra-Balsells, A.H. Thomas y F.M. Cabrerizo
Chemical Physics Letters, 484 (4-6), 330-332 (2010).

* “Visible-light photochemistry of 6-formyl-7,8-dihydropterin in aqueous solution.”
M.L. Dántola, A.H. Thomas, E. Oliveros y C. Lorente
Journal of Photochemistry and Photobiology A: Chemistry, 209 (2-3), 104-110 (2010).

* “Electron-transfer processes induced by the triplet state of pterins in aqueous solutions.”
M.L. Dántola, M. Vignoni, M.C. González, C. Lorente, P. Vicendo, E. Oliveros y A.H. Thomas
Free Radical Biology and Medicine, 49 (6), 1014-1022 (2010).

* “Mechanism of photooxidation of folic acid sensitized by unconjugated pterins.”
M.L. Dántola, M.P. Denofrio, B. Zurbano, C.S. Jiménez, R.P. Ogilby, C. Lorente y A.H. Thomas
Photochemical and Photobiological Sciences , 9 (12), 1604-1612 (2010).

* “Comment on "excited-state intermolecular proton transfer of lumazine" .”
M.P. Denofrio, A.H. Thomas, A.M. Braun, E. Oliveros y C. Lorente
Journal Physics Chemistry C, 114 (33), 14307-14308 (2010).

* “Study of the Photosensitizing activity of lumazine using 2'-deoxyguanosine 5'-monophosphate and hela cells as targets.”
M.P. Denofrio, S. Hatz, C. Lorente, F.M. Cabrerizo, P.R. Ogilby y A. Thomas
Photochem. Photobiology Science, 8, 1539-1549 (2009).

* “Quenching of the fluorescence of aromatic pterins by deoxynucleotides.”
G. Petroselli, M.L. Dántola, F.M. Cabrerizo, C. Lorente, A.M. Braun, E. Oliveros y A. Thomas
The Journal of Physical Chemistry A, 113, 1794-1799 (2009).

* “New results on the photochemistry of biopterin and neopterin.”
M. Vignoni, F.M. Cabrerizo, C. Lorente y A.H. Thomas
Photochemistry and Photobiology, 85, 365-373 (2009).

* “Oxidation of 2'-deoxyguanosine 5'-monophosphate photoinduced by pterin: type I versus type II mechanism.”
G. Petroselli, M.L. Dántola, F.M. Cabrerizo, A.L. Capparelli, C. Lorente, E. Oliveros y A.H. Thomas
Journal of the American Chemical Society, 130, 3001-3011 (2008).

* “Stability of 7,8-dihydropterins in air-equilibrated aqueous solutions.”
M.L. Dántola, M. Vignoni, A.L. Capparelli, C. Lorente y A.H. Thomas
Helvetica Chimica Acta, 91, 379-580 (2008).

* “Photochemical and photophysical properties of lumazine in aqueous solutions.”
M.P. Denofrio, A.H. Thomas, A.M. Braun, E. Oliveros y C. Lorente
Journal of Photochemistry and Photobiology A: Chemistry, 200, 282-286 (2008).

* “Reaction between 7,8-dihydropterins and hydrogen peroxide under physiological conditions.”
M.L. Dántola, T.M. Schuler, M.P. Denofrio, M. Vignoni, A.L. Capparelli, C. Lorente y A.H. Thomas
Tetrahedron, 64, 8692-8699 (2008).

* “Photosensitization of 2'-deoxyadenosine-5'-monophosphate by pterina.”
G. Petroselli, R. Erra-Balsells, F.M. Cabrerizo, C. Lorente, A.L. Capparelli, A.M. Braun, E. Oliveros y A.H. Thomas
Organic and Biomolecular Chemistry, 5, 2792-2799 (2007).

* “Singlet Oxygen (O₂(¹Δ_g)) Production and Quenching by Dihydropterins.”
M.L. Dántola, A.H. Thomas, A.M. Braun, E. Oliveros y C. Lorente
Journal of Physical Chemistry A, 111, 4280-4288 (2007).

* “Reactivity of Conjugated and Unconjugated Pterins with Singlet Oxygen (O₂(¹Δ_g)): Physical Quenching and Chemical Reaction.”
F.M. Cabrerizo, M.L. Dántola, G. Petroselli, A.L. Capparelli, A.H. Thomas, A.M. Braun, C. Lorente y E. Oliveros
Photochemistry and Photobiology, 83, 526-534 (2007).