Heterocyclic Thiosemicarbazones: Correlation Between Structure,Inhibition of Ribonucleotide Reductase,and Inhibition of DNA Viruses 1

Summary

The thiosemicarbazones of 2-formylpyridine, 3-formylpyridine, 4-for-mylpyridine, 5-hydroxy-2-formylpyridine, 1-formylisoquinoline, 5-hydroxy-1-formylisoquinoline, 6-formylpurine, isatin, and 1-methylisatin were examined for activity against herpes simplex virus in H.Ep.−2 cells and human cytomegalovirus in WI-38 cells, and also for inhibition of ribonucleotide reductase activity in H.Ep.−2 cells. A correlation was seen between inhibition of reductase and antiviral activity, with those compounds having the -CH=N-NH-C(=S) -NH₂ moiety affixed to the heterocyclic ring system in the position alpha to the ring nitrogen being active. The suggestion is made that the activity of ribonucleotide reductase may be a limiting factor in the replication of certain members of the herpesvirus group.