Anti-Influenza Virus Activity of 1-(4-Morpholinomethyl)-tetrahydro-2(1H)-pyrimidinone (Mopyridone)

Mopyridone inhibited the replication of influenza viruses A(H3N2), A(H2N2),) and B in MDCK and in primary calf kidney (CK) cell cultures, a higher activity been found in CK cells. The effects against A(H1N1) and A(H7N7) sybtypes strains were distinctly lower. Mopyridone at effective concentrations did not influence DNA, RNA and protein syntheses in intact cells. The compound-susceptible period in the influenza virus one-step growth cycle embraces the first 4 hours post virus adsorption. The high susceptibility of the A(H3N2) subtype to mopyridone was also manifested in embryonated eggs tests. Mopyridone was superior in comparison to rimantadine by its stronger and more selective in ovo effect. The compound demonstrated a marked anti-influenza activity in mice experimentally infected with influenza A(H3N2) and B viruses (even at massive virus inocula). This activity was similar to that of rimantadine by its protective rate, but a significantly higher by its selectivity: a selectivity (therapeutic) ratio value of 426 been recorded. Besides, mopyridone showed a week protective effect in the case of mouse infection with A/Puerto Rico/8/34 (H1N1) strain (drug-resistant in the in vitro experiments). The compound optimal treatment course was determined: 37.5 mg/kg orally daily (divided in two intakes) for 5 days from the day of infection.