Medical application of cytosine derivative

The invention provides a compound (I) or pharmaceutically acceptable salts, esters, optical isomers, tautomers, stereoisomers, polymorphs, solvates, N-oxides, isotope labeled compounds, metabolites, chelates, complexes, clathrates or prodrugs thereof, and a pharmaceutical composition containing the compound. Also provided are uses of the compounds of the invention as double-stranded DNA virus inhibitors. 本发明提供了化合物(I)或者其药学上可接受的盐、酯、光学异构体、互变异构体、立体异构体、多晶型物、溶剂合物、N-氧化物、同位素标记的化合物、代谢物、螯合物、络合物、包合物或前药，以及含有本发明的化合物的药物组合物，还提供本发明化合物作为双链DNA病毒抑制剂的用途。