Charles T. C. Chang

Antiviral, antitumor, and thymidylate synthetase inhibition studies of 5-substituted styryl derivatives of 2′-deoxyuridine and their 5′-phosphates

Abstract 2′-Deoxyuridine derivatives containing styryl, 3-nitrostyryl, 4-nitrostyryl, and phenylethyl groups substituted at the 5-position of the pyrimidine ring have been evaluated for their effects on vaccinia and herpes simplex virus replication (in primary rabbit kidney cell cultures) and mouse leukemia L-1210 cell culture growth. 5-Phenylethyl-2′-deoxyuridine inhibited herpes simplex (type 1 and 2) virus-induced cytopathogenicity by 50 per cent at a dose ( id 50 ) of 10–30 μg/ml. It was inactive against tumor cell growth. The corresponding styryl derivative showed an id 50 of 30–70 μg/ml for herpes simplex virus, 20 μg/ml for vaccinia virus, and 280 μg/ml for L-1210 cell growth. 5(E)-(3-Azidostyryl)-2′-deoxyuridine 5′-phosphate inhibited vaccinia replication with an IC 50 of 20 μg/ml and L-1210 cell culture growth with an id 50 of 80 μg/ml. The nucleotides of these compounds were all potent reversible inhibitors of thymidylate synthetase ( Lactobacillus casei ) with the following K i K m ratios: 3-nitrostyryl, 0.035; 4-nitrostyryl, 0.05; 3-azidostyryl, 0.06; styryl, 0.08; and phenylethyl, 0.31. The photodecomposition of the azidostyryl derivative, a photoaffinity labeling reagent for thymidylate synthetase, was examined at two wavelengths.

5-Nitro-2'-deoxyuridine 5'-monophosphate is a potent irreversible inhibitor of Lactobacillus caesi thymidylate synthetase.

Abstract 5-Nitro-2′-deoxyuridine 5′-monophosphate was found to be an active sitedirected irreversible inhibitor of thymidylate synthetase from Lactobacillus caesi . Its K I was determined as 2.9 × 10 −8 M from a double-reciprocal plot of velocity vs substrate concentration.

5(α-Bromoacetyl)-2′-deoxyuridine 5′-phosphate: A mechanism based affinity label for thymidylate synthetase

5(α-Bromoacetyl)-2′-deoxyuridine 5′-phosphate is an active site-directed irreversible inhibitor of thymidylate synthetase from Lactobacillus casei. The reversible inhibition (KI4uM) is competitive with substrate and on incubation the reversible enzyme-inhibitor complex is converted to the irreversible complex with a first order rate constant (k2) of 0.15 min−1.

5(E)-(3-azidostyryl)-2'-deoxyuridine 5'-phosphate is a photoactivated inhibitor of thymidylate synthetase.

Abstract The title compound is a photoaffinity labeling reagent for thymidylate synthetase, a key enzyme for the de novo biosynthesis of DNA. This compound is also a light-dependent inhibitor of murine (L-1210) and human (Namalva, Raji) tumor cell growth, and vaccinia virus replication.