A compound having the formula: ** Formula ** or a pharmaceutically acceptable salt or solvate thereof, wherein: R2 is selected from the group consisting of H and C1-C8 alkyl； R3 is selected from the group consisting of H, C1-C8 alkyl, C3-C8 carbocycle, aryl, C1-C8 alkylaryl, X1- (C3-C8 carbocycle), C3-C8 heterocycle and X1- (C3-C8 heterocycle) ； R4 is selected from the group consisting of H, C1-C8 alkyl, C3-C8 carbocycle, aryl, X1-aryl, C1-C8- alkyl (C3-C8 carbocycle), C3-C8 heterocycle and X1- (C3- heterocycle C8)； R5 is selected from the group consisting of H and methyl； or R4 and R5 together form a carbocyclic ring and have the formula - (CRaRb) n- in which Ra and Rb are independently selected from the group consisting of H, C1-C8 alkyl and C3-C8 carbocycle and n is selected from the group consisting of 2, 3, 4, 5 and 6； R6 is selected from the group consisting of H and C1-C8 alkyl； R7 is selected from the group consisting of H, C1-C8 alkyl, C3-C8 carbocycle, aryl, X1-aryl, X1- (C3-C8 carbocycle), C3-C8 heterocycle and X1- (C3-C8 heterocycle)； each R8 is independently selected from the group consisting of H, OH, C1-C8 alkyl, C3-C8 carbocycle and O- (C1-C8 alkyl)； each X1 is independently C1-C10 alkylene； the remainder -NR9Z1 is a phenylalanine bioistero with a modified amino acid side chain wherein the phenylalanine bioisocyte moiety ** Formula ** is where R9 is H； R10 is benzyl； R11 is H； Z2 is CO2H； subindice n is an integer from 0 to 2； and the subindice or is an integer from 0 to 2 on condition that n + or at least 1.Un compuesto que tiene la formula:**Fórmula** o una sal o un solvato farmaceuticamente aceptables del mismo, en la que: R2 se selecciona entre el grupo que consiste en H y alquilo C1-C8； R3 se selecciona entre el grupo que consiste en H, alquilo C1-C8, carbociclo C3-C8, arilo, alquilarilo C1-C8, X1- (carbociclo C3-C8), heterociclo C3-C8 y X1-(heterociclo C3-C8)； R4 se selecciona entre el grupo que consiste en H, alquilo C1-C8, carbociclo C3-C8, a
