Phosphate radical induced oxidation of pyrimidine bases in aqueous solution.
Indian J Biochem Biophys
;
2000 Feb; 37(1): 13-7
Article
in English
| IMSEAR
| ID: sea-27372
ABSTRACT
The photooxidation of pyrimidine bases viz., uracil and cytosine in presence of peroxydiphosphate (PDP) in aqueous solution at natural pH (approximately 7.5) has been carried out in a quantum yield reactor using a high-pressure mercury lamp. The rates of oxidation and quantum yields of pyrimidine oxidation have been found to increase with increase in [PDP] while they are independent of [pyrimidine] and light intensity. On the basis of these experimental results, product analysis and existence of isosbestic points a probable mechanism is suggested in which peroxydiphosphate ion on photolysis gives phosphate radical anions which initiates the reaction by adding to C(5) or C(6) of pyrimidine base leading to the formation of pyrimidine radical via radical cation or hydrolysis. This further reacts with PDP and gives the final products 5,6-dihydroxy pyrimidine and isobarbituric acid.
Full text:
Available
Index:
IMSEAR (South-East Asia)
Main subject:
Oxidation-Reduction
/
Phosphates
/
Photolysis
/
Pyrimidines
/
Solutions
/
Water
/
Free Radicals
Language:
English
Journal:
Indian J Biochem Biophys
Year:
2000
Type:
Article
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