Compounds of formula (I): in which R represents: - a C2-C18 linear alkyl radical, or - a C3-C18 cyclic alkyl radical, or - a C3-C10 branched alkyl radical, or - a radical - CHR1-COOR2 in which: R1 represents H or a linear alkyl radical of C1-C6, cyclic of C3-C6 or branched of C3-C6, said radical possibly being (i) substituted with at least one group selected from>； = NH, -NH2, -NHR ', -NR'2,>； = O, -OH, - OR', -SH, -SR ', COOR', phenyl, phenyl substituted with OH or OR ', and / or (ii ) interrupted by a group -NH-, -N (COR ') - or -S-； with R 'designating a linear alkyl radical of C1-C6, cyclic of C3-C6, or branched of C3-C6； R2 represents a linear alkyl radical of C1-C6, cyclic of C3-C6 or branched of C3-C6； as well as its salts, its solvates and its optical isomers.Compuestos de fórmula (I): en la que R representa: - un radical alquilo lineal de C2-C18, o - un radical alquilo cíclico de C3-C18, o - un radical alquilo ramificado de C3-C10, o - un radical -CHR1-COOR2 en el que: R1 representa H o un radical alquilo lineal de C1-C6, cíclico de C3-C6 o ramificado de C3-C6, pudiendo estar dicho radical eventualmente (i) sustituido con al menos un grupo seleccionado entre >；=NH, -NH2, -NHR', -NR'2, >；=O, -OH, - OR', -SH, -SR', COOR', fenilo, fenilo sustituido con OH u OR', y/o (ii) interrumpido por un grupo -NH-, -N(COR')- o -S-； con R' designando un radical alquilo lineal de C1-C6, cíclico de C3-C6, o ramificado de C3-C6； R2 representa un radical alquilo lineal de C1-C6, cíclico de C3-C6 o ramificado de C3-C6； así como sus sales, sus solvatos y sus isómeros ópticos.
