Patent ID: 8404664

Claim:
A compound of Formula (I) or a pharmaceutically acceptable salt thereof: wherein: B is a bisphosphonate is selected from the group consisting of: wherein: each R* is independently selected from the group consisting of H, lower alkyl, cycloalkyl, aryl and heteroaryl, with the proviso that at least two R* are H; X is H, OH, NH 2 , or a halo group; and X 1 are both H, or each is independently selected from the group consisting of H, OH, NH 2 , and a halo group; L is a cleavable linker for coupling B to A; m is 1, 2, 3 or 4; and A is a Rifamycin having a structure represented by the following Formula A1: wherein: X is H— or R 1 CO—, wherein R 1 is a substituted or unsubstituted alkyl chain of 1-6 carbons; each Y is independently selected from the group consisting of H— and RO—, wherein R is H—, R 1 —, or R 1 CO—, ith R 1 defined as above; is selected from the group consisting of formulae A2-A10: wherein R 2 is H—, a substituted or unsubstituted alkyl chain of 1-10 carbons, or a dialkyl amino group; R 3 is H— or a substituted or unsubstituted alkyl chain of 1-7 carbons; R 4 is a hydroxyl group, a sulfhydryl group or a substituted or unsubstituted alkyl chain of 1-3 carbons; W 1 is oxygen or —NR 2 with R 2 defined as above; W 2 is a substituted or unsubstituted methylene, comprising wherein R 5 and R 6 are independently H— or a substituted or unsubstituted alkyl chain of 1-5 carbons, and Z′ is an oxygen atom, a sulfur atom, a substituted methylene, a carbonyl, —NR 1 or —N(O)R 1 where R 1 is defined as above; T is a halogen or R 2 , where R 2 is defined as above; and Z is O, S or NR 3 , where R 3 is defined as above, wherein at least one of said B-L- is coupled to a nitrogen atom on said Rifamycin A, and wherein each of said B-L- coupled to a nitrogen atom is independently selected from the group consisting of: wherein: B represents said bisphophonate; n is an integer ≦10; each p is independently 0 or an integer ≦10; each R L is independently selected from the group consisting of H, ethyl and methyl; q is 2 or 3; X is O, —CONR L —, —CO—O—CH 2 —, or —CO—O—; and R a is C x H y where x is an integer of 0 to 20 and y is an integer of 1 to 2x+1.