Abstract: The present invention pertains to acridone and acridine compounds of formula (I), wherein either: (a) K is ?O, L is —H, alpha single bond, beta is a double bond, gamma is a single bond (acridones); or, (b) K is a 9-substituent, L is absent, alpha is a double bond, beta is a single bond, gamma is a double bond (acridines); and wherein: J1 is a 2- or 3-substituent; J2 is a 6- or 7-substituent; J1 and J2 are each independently a group of the formula —NHCO(CH2)nNR1R2, wherein: n is an integer from 1 to 5; and, R1 and R2 are independently hydrogen, C1-7alkyl, C3-20heterocyclyl, or C5-20aryl, or R1 and R2, taken together with the nitrogen atom to which they are attached, form a heterocyclic ring having from 3 to 8 ring atoms; and wherein, when K is a 9-substituent, K is a group of the formula —N(RN)Q, wherein: RN is an amino substituent and is hydrogen, C1-7alkyl, C3-20heterocyclyl, or C5-20aryl; and, Q is C1-7alkyl, C3-20heterocyclyl, or C5-20aryl, and is optionally substituted; and pharmaceutically acceptable sal