Photoinduced formation of reactive oxygen species from the acid form of 6-(hydroxymethyl)pterin in aqueous solution
The photochemistry of 6-(hydroxymethyl)pterin (HPT; 1) in aqueous solution (pH 5-6) was investigated by irradiation at 350 nm at room temperature. The photochemical reactions of the acidic form 1a were followed by UV/VIS spectrophotometry, thin-layer chromatography (TLC), high-performance liquid chr...
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| Autores principales: | , , , , , |
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| Formato: | JOUR |
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_0018019X_v89_n6_p1090_Thomas |
| Aporte de: |
| Sumario: | The photochemistry of 6-(hydroxymethyl)pterin (HPT; 1) in aqueous solution (pH 5-6) was investigated by irradiation at 350 nm at room temperature. The photochemical reactions of the acidic form 1a were followed by UV/VIS spectrophotometry, thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), and enzymatic methods for the determination of the superoxide anion radical (O2 .-) and hydrogen peroxide (H2O2). When 1a is exposed to UV-A radiation, the intermediates 4 and 4′ are formed reacting with O2 to yield 6-formylpterin (FPT; 5) and 6-carboxypterin (CPT; 6). under formation of O 2 .- and H2O2 (Scheme 3). The quantum yields of the disappearance of HPT (1a) and of the formation of the photoproducts 5 and 6 were determined. HPT was investigated for its efficiency in singlet-oxygen (1O2) production in acidic aqueous solution. The corresponding quantum yield of 1O2 production (ΦΔ) was 0.15±0.02, as measured by the 1O2 luminescence in the near-IR (1270 nm) upon continuous excitation of the sensitizer. However, 1O2 does not participate in the actual photooxidation of HPT (1a) to FPT (5) and CPT (6). © 2006 Verlag Helvetica Chimica Acta AG. |
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