Patent ID: 7560434

Claim:
A compound or a pharmaceutically acceptable salt thereof represented by the formula: wherein, R 1 is H, CH 3 , C 2 H 5 , or C 3 H 7 ; R 2 is H, CH 3 , C 2 H 5 , C 3 H 7 , CH═CH 2 , CH 2 —OH, CH 2 F, or CF 3 ; R′ 2 is OH, NH 2 , NH-alkyl, F, N 3 , OCH 3 , or O—C(O)CH(NH 2 )alkyl; R 3 is H, CH 3 , C 2 H 5 , or C 3 H 7 ; R′ 3 is H, OH, NH 2 , NH-alkyl, F, N 3 , OCH 3 , or O—C(O)CH(NH 2 )alkyl; R 4 is H, CH 3 , C 2 H 5 , or C 3 H 7 ; at least one of R 2 , R 3 , and R 4 has to be other than H, when X═NH in B R 6 is H or R 7 is selected from H, alkyl, alkenyl, aryl, acyloxyalkyl, and pivaloyloxyalkyl, aminoacids, and CH 2 CH 2 SC(O)alkyl; B is represented by the following structure: X is NR 6 , O, or S; R 8 is H, NH 2 , OH, SH, F, Cl, Br, I, aryl, heterocycle, alkyl, alkene, alkyne, S-alkyl, S-aryl, S(O)-alkyl, SO 2 -alkyl, SO 2 NH 2 , SO 2 NH-alkyl, SO 2 NH-aryl, NH-alkyl, NH-aryl, N(alkyl) 2 , N(aryl) 2 , O-alkyl, O-aryl, O-heterocycle, NH-(CH 2 ) n -aryl, NH—C(O)-alkyl, or NH—C(O)-aryl; and R 9 is H, NH 2 , OH, SH, F, Cl, Br, I, aryl, heterocycle, alkyl, alkene, alkyne, S-alkyl, S-aryl, S(O)-alkyl, SO 2 -alkyl, SO 2 NH 2 , SO 2 NH-alkyl, SO 2 NH-aryl, NH-alkyl, NH-aryl, N(alkyl) 2 , N(aryl) 2 , O-alkyl, O-aryl, O-heterocycle, NH-(CH 2 ) n -aryl, NH—C(O)-alkyl, or NH—C(O)-aryl.