Pyrazofurin

Pyrazofurin is an antitumor pyrimidine nucleoside analogue and a orotate-phosphoribosyltransferase inhibitor. Pyrazofurin inhibits cell proliferation and intracellular DNA synthesis by inhibiting uridine 5'-phosphate synthase. Pyrazofurin is also an antibiotic with a broad spectrum of antiviral activity^[1][2][3][4]. In Vitro: Pyrazofurin (75 μM; 52 h) inhibits DNA synthesis in guinea pig lymphocytes treated with Canavagin A(HY-P2149), but is reversed by exogenous uridine^[1].
Pyrazofurin (0.01-200 μM; 24-96 h) inhibits the growth of head and neck cancer cell lines HEP-2, UMSCC-14B and UMSCC-14C with the IC₅₀ between 0.06 and 0.37 μM, and decreases the levels of intracellular UTP and CTP and increases the levels of ATP and GTP^[2].
Pyrazofurin (0.1-100 μM; 72 h) inhibits parainfluenza type 3, measles, vaccinia, and herpes simplex type 2 viruses in Vero cells with the ED₅₀ between 2.8 and 20 μM ^[3]. In Vivo: Pyrazofurin (0.25-5 mg/kg; subcutaneous injection; 5 days) has an ameliorative effect in mice infected with Rift Valley fever virus^[4].