title: Analogues of pyrimidine base precursors as antiphytoviral agents.
abstract: Dihydroorotic acid hydrazide (DHOH) did not inhibit the replication of potatovirus X (PVX) in leaf disks of Nicotiana tabacum 'Samsun'. In contrast, 5-fluoroorotic acid (5-FOA) completely inhibited the replication of PVX, as demonstrated by a serological virus assay as well as a local lesion bioassay using Gomphrena globosa as the test plant. The corresponding base analogue 5-fluorouracil (5-FU) had only a weak inhibitory effect. Time-course inhibition experiments in synchronized virus-infected leaf disks led us to conclude that 5-FOA, as well as 5-azadihydrouracil (5-ADHU), an uracil catabolite analogue, inhibit the same early event in virus infection. Neither 5-FOA nor 5-ADHU had a direct inactivating effect on free PVX virions.
mesh_terms: D000998:Antiviral Agents / Q000494:pharmacology*; D003513:Cycloheximide / Q000494:pharmacology; D005472:Fluorouracil / Q000494:pharmacology; D009963:Orotic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D010942:Plant Viruses / Q000187:drug effects* / Q000502:physiology; D013889:Thiouracil / Q000494:pharmacology; D014227:Triazines / Q000494:pharmacology; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D000998:Antiviral Agents; D014227:Triazines; C020894:dioxohexahydrotriazine; D013889:Thiouracil; D009963:Orotic Acid; C053002:dihydroorotic acid hydrazide; C001242:5-fluoroorotic acid; D003513:Cycloheximide; D005472:Fluorouracil