Patent ID: 7476653

Claim:
The compound of the formula (II): or a pharmaceutically acceptable salt thereof, wherein: R 50 is —(CH 2 ) ss CH 3 , —CH(CH 3 )(CH 2 ) tt CH 3 , —(CH 2 ) uu CH(CH 3 ) 2 , —C(CH 3 ) 3 , —(CHR 55 ) vv —R 56 , or —CH(OR 57 )CH 3 , wherein ss is 0, 1, 2 or 3; tt is 1 or 2; uu is 0, 1 or 2; and vv is 0, 1, 2, 3 or 4; R 55 is hydrogen or C 1 -C 4 alkyl; R 56 is cycloalkyl substituted cycloalkyl, aryl, substituted aryl, heteroaryl or substituted heteroaryl, and when vv is 1, 2 or 3, R 56 is also amino, hydroxy or alkoxy; and R 57 is hydrogen or lower alkyl; and R 50′ is hydrogen; or R 50 and R 50′ , taken together with the carbon to which they are attached, form a C 3 -C 6 ring; R 51 is hydrogen, C 1 -C 4 alkyl or C 1 -C 4 alkyl substituted with hydroxy or alkoxy; and R 51′ is hydrogen; or R 51 and R 51′ , taken together with the carbon to which they are attached, form a C 3 -C 6 ring, optionally comprising O, S or NH in the ring; R 52 is —(CHR 58 ) ww R 59 , wherein ww is 0, 1, 2 or 3; R 58 is hydrogen, C 1 -C 4 alkyl and when ww is 1, 2 or 3, R 58 is also amino, hydroxy or alkoxy; R 59 is aryl, substituted aryl, heteroaryl, substituted heteroaryl, cycloalkyl or substituted cycloalkyl; R 53 is hydrogen or C 1 -C 4 alkyl; X 2 is NR 9 or N(R 10 ) 2 + ; wherein R 9 and R 10 are independently hydrogen or lower alkyl; Z 5 is NR 12 , wherein R 12 is hydrogen or lower alkyl; and T 2 is selected from the group consisting of the following: wherein (Z 5 ) is the site of a covalent bond of T 2 to Z 5 , and Z 5 is NR 12 , wherein R 12 is hydrogen or lower alkyl, and wherein (X 2 ) is the site of a covalent bond of T 2 to X 2 , and X 2 is NR 9 or N(R 10 ) 2 + , wherein R 9 and R 10 are independently hydrogen or lower alkyl; U 2 is —CR 95 R 96 — or —C(═O)—; L 6a-n is —CH 2 or —O—; R 90 is alkyl, substituted alkyl, aryl or substituted aryl; R 91 , R 92 , R 93 , R 95 and R 96 are each independently hydrogen or lower alkyl; and R 94 is hydrogen, lower alkyl, substituted lower alkyl or oxo, with the proviso that when T 2 is at least one of R 50 , R 51 and R 52 is not selected from the group consisting of the following: wherein Rp is selected from the group consisting of H and a protecting group.