Compound of formula (IIa) of the following general formula: ** Formula ** in which: R1, R2 and R3 represent, independently of each other, -COOH, -P (O) (OH) 2 or -R6-P ( O) -OH, wherein R6 represents an H atom or a C1-C3 alkyl group； X1, X2 and X3 represent, independently of each other, LY in which L represents a C1-C3 alkyl group, Y represents -NR7-CO-R8 in which R7 represents H or a C1-C6 alkyl group or a C1 hydroxyalkyl group -C6, and R8 represents a C1-C6 alkyl or C1-C6 hydroxyalkyl group, provided that at least R7 or R8 represents a C1-C6 hydroxyalkyl group； D represents CH or N； E represents CH or N； F1 represents CH or N； K1 to K12 each independently represent H, - (CH2) j-CH3 or - (CH2) i-OH, where j>； = 0 to 3 and i>； = 1 to 3, or K3 or K4 with K5 or K6 and / or K7 or K8 with K9 or K10, form a ring having 3 to 6 carbon atoms； or an enantiomer or a diastereoisomer of these or mixtures thereof.Compuesto de fórmula (IIa) de la siguiente fórmula general:**Fórmula** en la que: R1, R2 y R3 representan, independientemente entre sí, -COOH, -P(O)(OH)2 o -R6-P(O)-OH, en el que R6 representa un átomo de H o un grupo alquilo C1-C3； X1, X2 y X3 representan, independientemente entre sí, L-Y en el que L representa un grupo alquilo C1-C3, Y representa -NR7-CO-R8 en el que R7 representa H o un grupo alquilo C1-C6 o un grupo hidroxialquilo C1-C6, y R8 representa un grupo alquilo C1-C6 o hidroxialquilo C1-C6, siempre que al menos R7 o R8 represente un grupo hidroxialquilo C1-C6； D representa CH o N； E representa CH o N； F1 representa CH o N； K1 a K12 representan cada uno independientemente H, -(CH2)j-CH3 o -(CH2)i-OH, en los que j>；=0 a 3 e i>；=1 a 3, o K3 o K4 con K5 o K6 y/o K7 o K8 con K9 o K10, forman un anillo que tiene de 3 a 6 átomos de carbono； o un enantiómero o un diastereoisómero de estos o sus mezclas.
