A compound of formula or a pharmaceutically acceptable salt thereof: wherein m is 0, 1, 2, 3, 4, or 5; p is 0, 1, 2, or 3; A is single or double carbon-carbon bond; Ar 1 is 5- or 6-membered heteroaryl, each of which is optionally substituted with one or more substituents, each substituent independently being halogen, nitro, C 1 -C 4 alkyl, C 1 -C 4 hydroxyalkyl, OR a, or N(R a R a'), in which each R a, independently, is H or C 1 -C 4 alkyl and each R a', independently, is H or C 1 -C 4 alkyl; Ar 2 is aryl or 5- or 6-membered heteroaryl, each of which is optionally substituted with one or more substituents, each substituent independently being halogen, cyano, nitro, C 1 -C 4 alkyl, C 1 -C 4 aminoalkyl, C 1 -C 4 hydroxyalkyl, OR b, N(R b R b'), C -N(R b R b'), or NH-C -N(R b R b'), in which each R b, independently, is H or C 1 -C 4 alkyl and each R b', independently, is H or C 1 -C 4 alkyl; Ar 3 is aryl or 5- or 6-membered heteroaryl, each of which is optionally substituted with one or more substituents, each substituent independently being halogen, C 1 -C 4 alkyl, C 1 -C 4 hydroxyalkyl, OR c, or N(R c R c'), in which each R c, independently, is H or C 1 -C 4 alkyl and each R c', independently, is H or C 1 -C 4 alkyl; each R 1, independently, is C 1 -C 4 alkyl, C 1 -C 4 aminoalkyl, C 1 -C 4 hydroxyalkyl, OR d, or C -N(R d R d'), in which each R d, independently, is H or C 1 -C 4 alkyl and each R d', independently, is H or C 1 -C 4 alkyl; R 2 is -(CH 2) n -R, in which n is 0, 1, 2, or 3 and R is N(CH 3) 2, NH(CH(CH 3) 2), NH-C -CH(NH 2)-(CH 2) 4 -N(CH 3) 2, NH-C -CH 2 -(OCH 2 CH 2) 2 -NH 2, 3-amino-1,2,4-triazol-5-yl, N(CH 2 CH 3) 2, or guanidino substituted with CH 3; and each R 3, independently, is halogen, C 1 -C 4 alkyl, or OR f, in which each R f, independently, is H or C 1 -C 4 alkyl. m is 0, 1, 2, 3, 4, or 5; p is 0, 1, 2, or 3; A is single or double carbon-carbon bond; Ar 1 is 5- or 6-membered heteroaryl, each of which is optionally substituted with one or more substituents, each substituent independently being halogen, nitro, C 1 -C 4 alkyl, C 1 -C 4 hydroxyalkyl, OR a, or N(R a R a'), in which each R a, independently, is H or C 1 -C 4 alkyl and each R a', independently, is H or C 1 -C 4 alkyl; Ar 2 is aryl or 5- or 6-membered heteroaryl, each of which is optionally substituted with one or more substituents, each substituent independently being halogen, cyano, nitro, C 1 -C 4 alkyl, C 1 -C 4 aminoalkyl, C 1 -C 4 hydroxyalkyl, OR b, N(R b R b'), C -N(R b R b'), or NH-C -N(R b R b'), in which each R b, independently, is H or C 1 -C 4 alkyl and each R b', independently, is H or C 1 -C 4 alkyl; Ar 3 is aryl or 5- or 6-membered heteroaryl, each of which is optionally substituted with one or more substituents, each substituent independently being halogen, C 1 -C 4 alkyl, C 1 -C 4 hydroxyalkyl, OR c, or N(R c R c'), in which each R c, independently, is H or C 1 -C 4 alkyl and each R c', independently, is H or C 1 -C 4 alkyl; each R 1, independently, is C 1 -C 4 alkyl, C 1 -C 4 aminoalkyl, C 1 -C 4 hydroxyalkyl, OR d, or C -N(R d R d'), in which each R d, independently, is H or C 1 -C 4 alkyl and each R d', independently, is H or C 1 -C 4 alkyl; R 2 is -(CH 2) n -R, in which n is 0, 1, 2, or 3 and R is N(CH 3) 2, NH(CH(CH 3) 2), NH-C -CH(NH 2)-(CH 2) 4 -N(CH 3) 2, NH-C -CH 2 -(OCH 2 CH 2) 2 -NH 2, 3-amino-1,2,4-triazol-5-yl, N(CH 2 CH 3) 2, or guanidino substituted with CH 3; and each R 3, independently, is halogen, C 1 -C 4 alkyl, or OR f, in which each R f, independently, is H or C 1 -C 4 alkyl.