Patent ID: 8378099

Claim:
A compound having the formula: or a pharmaceutically acceptable salt thereof; wherein: P is hydrogen or an amino-group-protecting moiety; B 1 , at each occurrence, is independently one of N or CH; X 1 , at each occurrence, is independently one of —C(O)—NH—, —CH 2 —NH—, —CH(OH)—CH 2 —, —CH(OH)—CH(OH)—, —CH(OH)—CH 2 —NH—, —CH═CH—, —C(O)—CH 2 —, —SO 2 —NH—, —SO 2 —CH 2 —, or —CH(OH)—CH 2 —C(O)—NH—, provided that when B 1 is N, then the X 1 attached to said B 1 is —C(O)—NH—; X 2 is one of —C(O)—NH—, —CH(OH)—CH 2 —, —CH(OH)—CH(OH)—, —C(O)—CH 2 —, —SO 2 —NH—, —SO 2 —CH 2 —, or —CH(OH)—CH 2 —C(O)—NH—; R forms together with the adjacent R 1 , or when A is zero, forms together with the adjacent R 2 , a nitrogen-containing ring system selected from the group consisting of: when A is 2, the R 1 that is not adjacent to N—R is one of hydrogen, alkyl, cycloalkyl, aryl, a 5- to 10-membered saturated, partially unsaturated or aromatic heterocycle, or —CH 2 —R 5 ; when A is 1 or 2, the R 2 is one of hydrogen, alkyl, cycloalkyl, aryl, a 5- to 10-membered saturated, partially unsaturated or aromatic heterocycle, or —CH 2 —R 5 ; R 3 is one of hydrogen, alkyl, cycloalkyl, aryl, a 5- to 10-membered saturated, partially unsaturated or aromatic heterocycle, or —CH 2 —R 5 ; R 5 , in each instance, is independently one of aryl, aralkyl, alkaryl, cycloalkyl, a 5- to 10-membered saturated, partially unsaturated or aromatic heterocycle or —W—R 6 , where W is a chalcogen and R 6 is alkyl; Z 1 and Z 2 are independently one of alkyl, hydroxy, alkoxy, or aryloxy, or together Z 1 and Z 2 form a moiety derived from a dihydroxy compound having at least two hydroxy groups separated by at least two connecting atoms in a chain or ring, said chain or ring comprising carbon atoms, and optionally, a heteroatom or heteroatoms which can be N, S, or O; and A is 0, 1, or 2.