Abstract: This present disclosure is directed to compound of Formula I and methods of using these compounds in the treatment of conditions in which modulation of a cathepsin, particularly cathepsin L, cathepsin K, and/or cathepsin B, will be therapeutically useful. Formula I: or a solvate or pharmaceutically acceptable salt thereof. Each of R1-R10 are independently selected from the group consisting of: hydrogen, alkoxy, halo, hydroxy, phosphate, phosphate salts, disodium phosphate, diphosphate dimer, diphosphate dimer salt, and sodium diphosphate dimer with at least one of R1-R10 is a phosphate or diphosphate dimer group.