A compound of formula (I) or a pharmaceutically acceptable salt thereof is provided. In formula (I), Ar is indazole, 5-isoquinoline, 6-isoquinoline, or their N-oxide. X is —C(═Z)—, wherein Z is N—CN, NH, NR4, NCOR4, NCONR4R5, NCO-aryl, S, or O. Y and J are independently H, alkyl, aryl, aminoalkyl, —NH2, —CN, —OH, —O-alkyl, —O-aryl, —COOH, —COOR4, —CONHR4, —CONHCH2-aryl, —CONR4CH2-aryl, —NHCOR4, halogen, halogened alkyl, -alkyl-OR4, -alkyl-ONO2, alkyl-ONO2, —OCOOR4, —O(C═O)-aryl, —CHR4OH, —CH2OH, —CH2O(C═O)-aryl, —CH2O(C═O)—R4, —CHR4O(C═O)-aryl, —CHR4O(C═O)—R4, unsaturated carboxylic ester, substituted alkynyl, —NHSO2R4, —SO2R4, —SO2NHR4, or —SO2NR4R5, or Y and J bond together to form a carbocylic or aromatic ring, wherein R4 and R5 are independently H, substituted C1-C6 alkyl, substituted aryl, cycloalkyl, alkylaryl, -alkyl-NR6R7, —S(O)0-2-(alkyl-NR6R7). R1, R2 and R3 are H, C1-C6 alkyl, cycloalkyl, aryl, alkylaryl, alkylheteroaryl, alkylheterocycle, wherein any one thereof is optionally substituted with one or more of OH, NO2, or NR8R9.