A compound having a structure represented by formula wherein R 0 is NHR 1a, NHC(=O)OR 1b, NHC(=O)NHR 1b, OC(=O)NHR 1b, (CH 2) 1-4 NHR 1a, F, Cl, Br, OR 1a, or SR 1b; R 1a is H, C 1 -C 6 alkyl, (CH 2) n NH 2, C(=O)(CH 2) n NH 2, C(=O)CHR 8 NH 2, or C(=O)R 9 NH 2; R 1b is H, C 1 -C 6 alkyl, (CH 2) n NH 2, R 2 is H, R 10, C(=O)R 10, or C(=O)OR 10; R 3 is H or unsubstituted or substituted C 1 -C 6 alkyl; R 4 is OH, SH, NH 2, OR 10, SR 10, NHR 10, N(R 10) 2, NHC(=O)OR 10, OC(=O)NHR 1b, OC(=O)R 10, SC(=O)R 10, or NHC(=O)R 10; R 5 is OH, SH, NH 2, OR 10, SR 10, NHR 10, N(R 10) 2, NHC(=O)OR 10, OC(=O)NHR 1b, OC(=O)R 10, SC(=O)R 10, or NHC(=O)R 10; R 6 is H or unsubstituted or substituted C 1 -C 6 alkyl; or R 5 and R 6 combine to form =O; R 7 is OH, SH, NH 2, OR 10, SR 10, NHR 10, N(R 10) 2, NHC(=O)OR 10, OC(=O)NHR 1b; OC(=O)R 10, SC(=O)R 10, or NHC(=O)R 10; R 8 is the side chain residue of an α-amino acid selected from the group consisting of alanine, arginine, asparagine, aspartic acid, γ-carboxyglutamic acid, citrulline, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, norleucine, norvaline, ornithine, phenylalanine, serine, threonine, tryptophan, tyrosine, and valine; R 9 is unsubstituted or substituted arylene, unsubstituted or substituted heteroarylene, unsubstituted or substituted alkylarylene, unsubstituted or substituted cycloalkylene or unsubstituted or substituted heterocycloalkylene; each R 10 is independently unsubstituted or substituted C 1 -C 6 alkyl, unsubstituted or substituted cycloalkyl, unsubstituted or substituted heterocycloalkyl, unsubstituted or substituted arylalkyl, unsubstituted or substituted aryl; or unsubstituted or substituted heteroaryl; wherein the substituents of the substituted moieties are independently of each other chosen from alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloaliphatic, heterocycloaliphatic, halo, haloalkyl, hydroxyl, hydroxyalkyl, cyano, nitro, alkoxy, -O(hydroxyalkyl), -O(haloalkyl), -O(cycloalkyl), -O(heterocycloalkyl), -O(aryl), alkylthio, arylthio, =O, =NH, =N(alkyl), =NOH, =NO(alkyl), -C(=O)(alkyl), -C(=O)H, -CO 2 H, -C(=O)NHOH, -C(=O)O(alkyl), -C(=O)O(hydroxyalkyl), -C(=O)NH 2, -C(=O)NH(alkyl), -C(=O)N(alkyl) 2, -OC(=O)(alkyl), -OC(=O)(hydroxyalkyl), -OC(=O)O(alkyl), -OC(=O)O(hydroxyalkyl), -OC(=O)NH 2, -OC(=O)NH(alkyl), -OC(=O)N(alkyl) 2, azido, -NH 2, -NH(alkyl), -N(alkyl) 2, -NH(aryl), -NH(hydroxyalkyl), -NHC(=O)(alkyl), -NHC(=O)H, -NHC(=O)NH 2, -NHC(=O)NH(alkyl), -NHC(=O)N(alkyl) 2, -NHC(=NH)NH 2, -OSO 2 (alkyl), -SH, -S(alkyl), -S(aryl), -S(cycloalkyl), -S(=O)alkyl, -SO 2 (alkyl), -SO 2 NH 2, -SO 2 NH(alkyl), and -SO 2 N(alkyl) 2; and n is 2, 3, 4, 5, or 6; or a pharmaceutically acceptable salt thereof. R 0 is NHR 1a, NHC(=O)OR 1b, NHC(=O)NHR 1b, OC(=O)NHR 1b, (CH 2) 1-4 NHR 1a, F, Cl, Br, OR 1a, or SR 1b; R 1a is H, C 1 -C 6 alkyl, (CH 2) n NH 2, C(=O)(CH 2) n NH 2, C(=O)CHR 8 NH 2, or C(=O)R 9 NH 2; R 1b is H, C 1 -C 6 alkyl, (CH 2) n NH 2, R 2 is H, R 10, C(=O)R 10, or C(=O)OR 10; R 3 is H or unsubstituted or substituted C 1 -C 6 alkyl; R 4 is OH, SH, NH 2, OR 10, SR 10, NHR 10, N(R 10) 2, NHC(=O)OR 10, OC(=O)NHR 1b, OC(=O)R 10, SC(=O)R 10, or NHC(=O)R 10; R 5 is OH, SH, NH 2, OR 10, SR 10, NHR 10, N(R 10) 2, NHC(=O)OR 10, OC(=O)NHR 1b, OC(=O)R 10, SC(=O)R 10, or NHC(=O)R 10; R 6 is H or unsubstituted or substituted C 1 -C 6 alkyl; or R 5 and R 6 combine to form =O; R 7 is OH, SH, NH 2, OR 10, SR 10, NHR 10, N(R 10) 2, NHC(=O)OR 10, OC(=O)NHR 1b; OC(=O)R 10, SC(=O)R 10, or NHC(=O)R 10; R 8 is the side chain residue of an α-amino acid selected from the group consisting of alanine, arginine, asparagine, aspartic acid, γ-carboxyglutamic acid, citrulline, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, norleucine, norvaline, ornithine, phenylalanine, serine, threonine, tryptophan, tyrosine, and valine; R 9 is unsubstituted or substituted arylene, unsubstituted or substituted heteroarylene, unsubstituted or substituted alkylarylene, unsubstituted or substituted cycloalkylene or unsubstituted or substituted heterocycloalkylene; each R 10 is independently unsubstituted or substituted C 1 -C 6 alkyl, unsubstituted or substituted cycloalkyl, unsubstituted or substituted heterocycloalkyl, unsubstituted or substituted arylalkyl, unsubstituted or substituted aryl; or unsubstituted or substituted heteroaryl; wherein the substituents of the substituted moieties are independently of each other chosen from alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloaliphatic, heterocycloaliphatic, halo, haloalkyl, hydroxyl, hydroxyalkyl, cyano, nitro, alkoxy, -O(hydroxyalkyl), -O(haloalkyl), -O(cycloalkyl), -O(heterocycloalkyl), -O(aryl), alkylthio, arylthio, =O, =NH, =N(alkyl), =NOH, =NO(alkyl), -C(=O)(alkyl), -C(=O)H, -CO 2 H, -C(=O)NHOH, -C(=O)O(alkyl), -C(=O)O(hydroxyalkyl), -C(=O)NH 2, -C(=O)NH(alkyl), -C(=O)N(alkyl) 2, -OC(=O)(alkyl), -OC(=O)(hydroxyalkyl), -OC(=O)O(alkyl), -OC(=O)O(hydroxyalkyl), -OC(=O)NH 2, -OC(=O)NH(alkyl), -OC(=O)N(alkyl) 2, azido, -NH 2, -NH(alkyl), -N(alkyl) 2, -NH(aryl), -NH(hydroxyalkyl), -NHC(=O)(alkyl), -NHC(=O)H, -NHC(=O)NH 2, -NHC(=O)NH(alkyl), -NHC(=O)N(alkyl) 2, -NHC(=NH)NH 2, -OSO 2 (alkyl), -SH, -S(alkyl), -S(aryl), -S(cycloalkyl), -S(=O)alkyl, -SO 2 (alkyl), -SO 2 NH 2, -SO 2 NH(alkyl), and -SO 2 N(alkyl) 2; and n is 2, 3, 4, 5, or 6;