Synthesis and biological activity of 5-fluoro-2'-deoxyuridine 5'-phosphorodiamidates

Abstract

Three 5'-phosphorodiamidate derivatives of 5-fluoro-2'-deoxyuridine (FdUrd), 5-fluoro-2'-deoxyuridine 5'-phosphorodiamidate (4a), 5'-phosphorodiimidazolidate (4b), and 5'-phosphorodimorpholidate (4c), were synthesized by aminolysis of 5-fluoro-2'-deoxyuridine 5'-phosphorodichloridate with the respective amine. In culture, these 5'-phosphorodiamidates inhibited the growth of murine leukemia (L5178Y) cells. 5-Fluoro-2'-deoxyuridine 5'-phosphorodiamidate (4a) was the most active derivative and, on a molar basis, produced a cytostatic effect comparable to that of FdUrd and 5-fluoro-2'-deoxyuridine 5'-monophosphate (FdUrd-5'-P). Compounds 4b and 4c were less active than 4a, with relative rates of activity 4a > 4b > 4c that corresponded to their rates of hydrolysis to FdUrd-5'-P. None of the 5'-phosphorodiamidates inhibited thymidylate synthetase of concentrations up to 1 mM.

Pronucleotides: Toward thein vivo delivery of antiviral and anticancer nucleotides

“…15). 109 A positive correlation was reported between the in vitro growth inhibitory potency toward L5178Y cells and the rates of hydrolysis of the phosphorodiamidates to FUdR-MP at 100 C in 0.1 M phosphate buffer (pH 7.0). The phosphorodimorphodilate of FUdR was the least potent analog (11% growth inhibition at 10 À8 M) with a half-life of 100 hr at pH 7.0 at 100 C. Phosphorodiimidazolate of FUdR had a half-life of 12 hr and exhibited only modest growth inhibition potency (16% growth inhibition at 10 À8 M).…”

“…102, 103, 105^107 half-life of 3.9 hr). 109 Control experiments, however, found that FUdR-MP at 10 À8 M was able to inhibit 67% of the growth of L5178Y cells. Thus, the growth inhibitory activity of the phosphorodiamidates could be correlated to the rate of conversion to FUdR-MP, with decreased potency observed for compounds with the largest nitrogen-bearing substituents.…”

“…An IC 50 of 2 nM was observed for the phosphorodiamidates, 1.4 nM for FUdR-MP, and 0.76 nM for FUdR, suggesting that FUdR or FUdR-MP was the primary decomposition product. 109 Unlike FUdR-MP, none of the phosphorodiamidates were found to inhibit thymidylate synthetase in vitro at a concentration of 1 mM. 109 Although decomposition studies of the phosphorodiamidates were not carried out, it was postulated that the growth inhibition exhibited by phosphorodiamidates probably results from a hydrolytic product (probably FUdR-MP).…”

“…109 Unlike FUdR-MP, none of the phosphorodiamidates were found to inhibit thymidylate synthetase in vitro at a concentration of 1 mM. 109 Although decomposition studies of the phosphorodiamidates were not carried out, it was postulated that the growth inhibition exhibited by phosphorodiamidates probably results from a hydrolytic product (probably FUdR-MP). However, direct inhibition of thymidylate synthetase was not observed and an examination of the cellular metabolites of these compounds was not reported.…”

Novel Chemical Strategies for Thymidylate Synthase Inhibition

“…5'phosphordiamidate derivatives of FdUMP were synthesized and found to inhibit the growth of murine leukemia cells [5] can be cleaved to release FdUMP while the metabolic conversion of 5FU to FdUMP requires multiple enzymatic steps. [122]. The rates of activity corresponded to the rate of hydrolysis of the phosphordiamidate to FdUMP.…”