Dithymine photodimers and photodecomposition products of thymidylyl-thymidine induced by ultraviolet radiation from 150 to 300 nm
- Rikkyo (St. Paul`s) Univ., Tokyo (Japan)
Solid thymidylyl-(3{prime} {yields} 5{prime})-thymidine (dTpdT) was irradiated in a vacuum with monochromatic photons from 150 to 300 nm; the photoproducts were analyzed quantitatively by high-performance liquid chromatography. The results of the experiment were as follows: (1) above 210 nm the major photoproducts were three dithymine photodimers [the cis-syn and trans-syn cyclobutane thymine dimers and the thymine (6-4) photoproduct]; below 210 nm, they were three photodecomposition products (thymine, thymidine 5{prime}-monophosphate and thymidine 3{prime}-monophosphate). This shows that 210 nm is the wavelength at which the major photoproducts change from dithymine photodimers (far-UV type) to photodecomposition products (X-ray type). (2) The yields of the three dithymine photodimers had a similar wavelength dependence with each other: the yields had a peak at 260 nm and gradually decreased toward shorter wavelengths to 150 nm. (3) The yields of the three photodecomposition products also had a very similar wavelength dependence with each other; the yields increased exponentially with a decrease in the wavelength. (4) The average ratios of the yield of the (6-4) photoproduct to that of the cis-syn dimer were 0.30 between 170 and 220 nm, but 0.16 between 240 and 290 nm. 18 refs., 4 figs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 70206
- Journal Information:
- Radiation Research, Vol. 140, Issue 2; Other Information: PBD: Nov 1994
- Country of Publication:
- United States
- Language:
- English
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