A compound having a structure of formula: wherein: m is an integer selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, and 8; X 1 is selected from the group consisting of-O- and -(CH 2) p -, wherein p is an integer selected from the group consisting of 0, 1, 2, 3, 4, 5, 6, 7, and 8; R is H, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkenyl, substituted cycloalkenyl, tri(alkyl)ammonium, and tetra(alkyl)ammonium; R 3, R 5, and R 7 are each independently H, C 1 -C 6 alkyl, alkoxyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl; R 6 is selected from the group consisting of H, -(CH 2) t -CH(NH-C(CH 3)(=O))-(CH 2) t -R 9, -C(=O)-X 2 -R 10, and one or more substituted or unsubstituted amino acids, wherein the one or more substituted or unsubstituted amino acids is bound to the nitrogen atom adjacent to R 6 through a carboxyl moiety of the one or more substituted or unsubstituted amino acids, wherein X 2 is present or absent and, when present, is selected from the group consisting of-O-, -O-(CH 2) q -, -(CH 2) t -, and -(CH 2) v -CH=CH-(CH 2) v -, wherein q and t are each independently selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, and 8, each v is independently selected from the group consisting of 0, 1, 2, 3, 4, 5, 6, 7, and 8, and R 9 and R 10 are each independently selected from the group consisting of straight chain or branched alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl; and R 8 is selected from the group consisting of H and -C(=O)-R 11, wherein R 11 is substituted or unsubstituted alkyl; or an ester or pharmaceutically acceptable salt thereof. m is an integer selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, and 8; X 1 is selected from the group consisting of-O- and -(CH 2) p -, wherein p is an integer selected from the group consisting of 0, 1, 2, 3, 4, 5, 6, 7, and 8; R is H, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkenyl, substituted cycloalkenyl, tri(alkyl)ammonium, and tetra(alkyl)ammonium; R 3, R 5, and R 7 are each independently H, C 1 -C 6 alkyl, alkoxyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl; R 6 is selected from the group consisting of H, -(CH 2) t -CH(NH-C(CH 3)(=O))-(CH 2) t -R 9, -C(=O)-X 2 -R 10, and one or more substituted or unsubstituted amino acids, wherein the one or more substituted or unsubstituted amino acids is bound to the nitrogen atom adjacent to R 6 through a carboxyl moiety of the one or more substituted or unsubstituted amino acids, wherein X 2 is present or absent and, when present, is selected from the group consisting of-O-, -O-(CH 2) q -, -(CH 2) t -, and -(CH 2) v -CH=CH-(CH 2) v -, wherein q and t are each independently selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, and 8, each v is independently selected from the group consisting of 0, 1, 2, 3, 4, 5, 6, 7, and 8, and R 9 and R 10 are each independently selected from the group consisting of straight chain or branched alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl; and R 8 is selected from the group consisting of H and -C(=O)-R 11, wherein R 11 is substituted or unsubstituted alkyl; or an ester or pharmaceutically acceptable salt thereof.