Tetracyclic pyrimidinone compound, preparation method therefor, and composition and use thereof

A compound represented by formula (I):

• or a pharmaceutically acceptable salt thereof,
• wherein:
• n1, n2, n3, and n4 are each independently 0, 1, or 2;
• R1 and R2 are each independently selected from:
• —H, hydroxyl, cyano, halogen, alkyl, deuteroalkyl, hydroxyalkyl, haloalkyl, cycloalkyl, and alkoxyl;
• X1, X2, and X3 are each independently selected from:
• alkylene, —O—, —S—, or —NR′—;
• R′ is selected from:
• —H, alkyl, deuteroalkyl, or cycloalkyl;
• Ar is an unsubstituted or substituted arylene or heteroarylene;
• wherein, in the substituted arylene or heteroarylene, one or more hydrogen atoms are replaced by one or more substituents that are each independently selected from:
• halogen, alkyl, haloalkyl, alkoxyl, haloalkoxyl, deuteroalkyl, deuteroalkoxyl, hydroxyl, hydroxyalkyl, cyano, amino, monoalkyl- or dialkyl-substituted amino, nitro, carboxyl, aldehyde, cycloalkyl, heterocyclyl, aryl, or heteroaryl;
• Y is —H, halogen, alkyl, haloalkyl, haloalkoxyl, cycloalkyl, alkoxyl, deuteroalkyl, deuteroalkoxyl, —OAr′, —SAr′, —NH—Ar′, —NMe—Ar′, —NR′R″, or —R′″—Ar′;
• Ar′ is an unsubstituted or substituted aryl or heteroaryl;
• wherein, in the substituted aryl or heteroaryl, one or more hydrogen atoms are replaced by one or more substituents that are each independently selected from:
• halogen, alkyl, haloalkyl, alkoxyl, hydroxyl, hydroxyalkyl, haloalkoxyl, deuteroalkyl, deuteroalkoxyl, cyano, amino, nitro, carboxyl, aldehyde, cycloalkyl, heterocyclyl, aryl, or heteroaryl;
• R″ is alkyl;
• R′″ is alkylene;
• and
• Z is O or S.