Patent ID: 8211402

Claim:
A compound of Formula I or a pharmaceutically acceptable salt thereof: wherein W is a bond, a (C 1 -C 8 )alkyl, a (C 2 -C 8 )alkenyl, an aryl, a heteroaryl, a —NHC(O), —C(O)NH, —NH—C(O)—NH—, or —NH—C(S)—NH—; V is a bond, a (C 1 -C 8 )alkyl, a (C 2 -C 8 )alkenyl, an aryl, a heteroaryl, —NH—C(O)—NH—, or —NH—C(S)—NH—; NR a R b is a chelator group of Formula: R t is H, a C 1 -C 8 alkyl group, an ammonium ion, or an alkali or alkaline earth metal ion; R x and R y is independently hydrogen, alkyl, aminoalkyl, hydroxyalkyl or carboxyalkyl; R v is alkyl; m is an integer from 0 to 15; and n is an integer from 0 to 15.