A compound that can function as a Cyclophilin D can include a structure of Formula 1 or Formula 2 or Formula 3 or Formula 4 or Formula 5 or Formula 6 or Formula 7 or Formula 8, derivative thereof, prodrug thereof, salt thereof, or stereoisomer thereof, or having any chirality at any chiral center, or tautomer, polymorph, solvate, or combination thereof, as presented herein. The Cyclophilin D inhibitors can inhibit onset or treat neurodegenerative disease, such as Alzheimers disease, or can be used for inhibiting progression or treating diabetes. An example of such a compound is provided by Formula 1A
