title: Photochemistry of cytosine derivatives. 2. Photohydration of cytosine derivatives. Proton magnetic resonance study on the chemical structure and property of photohydrates.
abstract: Photohydrates of cytidine and cytidylic acids have been definitively characterized to be isomeric 6-hydroxy-5,6-dihydrocytosine derivatives. It has also been demonstrated by nuclear magnetic resonance spectroscopy that (1) the stereochemistry of photohydration is random, (2) the C5-H trans to the C6-OH undergoes a rapid selective exchange in the presence of proton acids, and (3) the dehydration of photohydrates is a trans-elimination. The mechanism of these processes is discussed.
mesh_terms: D003562:Cytidine / Q000031:analogs & derivatives; D003568:Cytidine Monophosphate; D003596:Cytosine / Q000031:analogs & derivatives*; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D010777:Photochemistry; D014542:Uridine Monophosphate
chemical_list: D003562:Cytidine; D003596:Cytosine; D014542:Uridine Monophosphate; D003568:Cytidine Monophosphate