Characterization of 5-hydroxy-8-oxo-7,8-dihydroguanosine in the photosensitized oxidation of 8-oxo-7,8-dihydroguanosine and its rearrangement to spiroiminodihydantoin. - McCallum JE; Kuniyoshi CY; Foote CS (Journal of the American Chemical Society, 2004)