Small molecule inhibitors of the mitochondrial permeability transition pore (mtPTP)

A compound according to Formula I:

• or a pharmaceutically acceptable salt thereof, wherein:
• Y1 is O;
• W1 is N;
• Z1, Z2, and Z3 are each independently CH, C—R9, or N;
• m is 1;
• G1 is C═O;
• R1 is
• R2, R4, R5, and R9 are independently at each occurrence hydrogen, halogen, hydroxyl, alkyl, cycloalkyl, alkenyl, alkoxy, alkynyl, amino, aminosulfinyl, aminosulfonyl, sulfinyl, sulfonyl, sulfonyloxy, aminosulfonyloxy, aminosulfinyloxy, aminosulfonylamino, acylamino, aminocarbonyloxy, aminocarbonylamino, aminothiocarbonylamino, aminocarbonyl, acyloxy, aryl, heteroaryl, heterocyclyl, cyano, nitro, carboxyl, carboxyl ester, (carboxyl ester)amino, (carboxyl ester)oxy, acyl, or formyl;
• or two adjacent R4, R5, and R9 together form an aryl, heteroaryl, or heterocyclyl ring;
• R3 is hydrogen, alkyl, cycloalkyl, alkenyl, or alkynyl;
• and
• R21 is F or Cl.