Myc g-quadruplex stabilizing small molecules and their use

A method of decreasing c-Myc expression in a cell, comprising contacting the cell with an effective amount of a compound, or a pharmaceutically acceptable salt thereof, having a structure of:

• wherein:
• A is a 6 membered aryl ring;
• C is a 6-membered aryl ring;
• each R1 is independently selected from hydrogen or optionally-substituted lower alkyl;
• a is 0, 1, or 2;
• R2 is selected from hydroxyl or halogen;
• R8 and R9 together with the linking nitrogen atom form a 4 to 7 membered optionally-substituted N-hetero- mono- or bi-cyclic ring with one or two hetero atoms independently selected from nitrogen and oxygen;
• each R3 is independently selected from halogen, lower haloalkyl, or optionally-substituted lower alkyl;
• b is 0 to 4;
• R4 is selected from halogen, lower haloalkyl, or optionally-substituted lower alkyl;
• each R5 is independently selected from halogen, lower haloalkyl, or optionally-substituted lower alkyl;
• d is 0, 1, or 2;
• R6 is selected from methyl, trifluoromethyl, or phenyl;
• Z is selected from nitrogen or oxygen;
• if Z is nitrogen, R7 is selected from hydrogen, hydroxyl, halogen, lower haloalkyl, or optionally-substituted lower alkyl, and if Z is oxygen, R7 is not present;
• and
• wherein each substituted lower alkyl and substituted N-hetero- mono- or bi-cyclic ring is independently selected from a lower alkyl or N-hetero- mono- or bi-cyclic ring wherein one or more hydrogen atoms are replaced with C1-6alkyl, C2-6alkenyl, C2-6alkynyl, C3-8cycloalkyl, hydroxyl, oxo, C1-6alkoxy, aryloxy, C1-6alkoxyaryl, C1-6alkylhalo, C1-6alkoxyhalo, carboxyl, cyano, nitro, amino, acyl, amido, aminoacyl, mercapto, alkylthio, thioxo, sulfates, sulfonates, sulfinyl, sulfonyl, sulfonylamido, aryl, arC1-6alkyl, heterocyclyl, heteroaryl, or halogen.