The aim of the present work is to determine the influence of C5 substitution on the photophysical properties of 2-thiopyrimidines (2-TPyr). For this purpose, 2-thiouracil, 5-t-butyl-2-thiouracil and 2-thiothymine (TU, BTU and TT, respectively) have been selected as target thionucleobases for the experimental studies and, in parallel, for DFT theoretical calculations. The UV spectra displayed by...

T HE anti-thyroid drugs, thiouracil and 6 n-propylthiouracil have been reported to cause leukopenia and granulocytopenia in man and experimental animals. ‘ Some evidence has been found to support the view that concurrent administration of liver preparations and folic acid may have beneficial effect on the toxicity of thiourea and thiopyrimidines, including the blood dyscrasias.’#{176} 2 In view...

A method is described for the incorporation of 2'-deoxy-2-thiouridine (dS2U) and 2'-deoxy-2-thiothymidine (dS2T) into oligodeoxynucleotides at predetermined positions. This requires N3 or O4-acylation of dS2U and dS2T with toluoyl chloride. These base-protected thiopyrimidines are completely stable toward the aqueous iodine oxidation reagent used in the phosphoramidite DNA synthesis method. The...