Compound of formula I ** Formula ** in which: R1 is H, C1-7 haloalkyl, or aryl, wherein aryl is phenyl or naphthyl, optionally substituted with one or more C1-7 alkyl, C2-7 alkenyl, C2-7 alkynyl, C1-7 alkoxy, halo, C1-7 haloalkyl, -N (R1a) 2, acylamino, -SO2N (R1a) 2, -COR1b, -SO2 (R1c), -NHSO2 (R1c), nitro or cyano; each R1a is independently H or C1-7 alkyl; each R1b is independently -OR1a or -N (R1a) 2; each R1c is C1-7 alkyl; R2a and R2b are (i) independently H, C1-7 alkyl, - (CH2) rN (R1a) 2, hydroxy C1-7 alkyl, -CH2SH, - (CH2) S (O) pMe, - (CH2) 3NHC (>; = NH) NH2, (1H-indole-3-yl) methyl, (1H-indole-4-yl) methyl, - (CH2) mC (>; = O) R1b, aryl and aryl C1-7 alkyl, in which the aryl may be optionally substituted with one or more hydroxy, C1-7 alkyl, C1-7 alkoxy, halo, nitro or cyano; (ii) R2a is H and R2b and R4 together form (CH2) 3; (iii) R2a and R2b together form (CH2) n; or, (iv) R2a and R2b are both C1-7 alkyl; R3 is H, C1-7 alkyl, C1-7 haloalkyl, phenyl or phenyl C1-7 alkyl; R4 is H, C1-7 alkyl, or R2b and R4 together form (CH2) 3; R5 is H, C (>; = O) R1c, C (>; = O) R1b, P (>; = O) (OR1) (OR1a), or P (>; = O) (OR1) (NR4R7); R6 is H, methyl, or halo; R7 is C (R2aR2b) COOR3; m is from 0 to 3; n is 4 or 5; p is 0 to 2; and r is from 1 to 6; or a pharmacologically acceptable salt thereof.Compuesto de fórmula I**Fórmula** en la que: R1 es H, haloalquilo C1-7, o arilo, en la que arilo es fenilo o naftilo, opcionalmente sustituido con uno o más alquilo C1- 7, alquenilo C2-7, alquinilo C2-7, alcoxi C1-7, halo, haloalquilo C1-7, -N(R1a)2, acilamino, -SO2N(R1a)2, -COR1b, -SO2(R1c), -NHSO2(R1c), nitro o ciano; cada R1a es independientemente H o alquilo C1-7; cada R1b es independientemente -OR1a o -N(R1a)2; cada R1c es alquilo C1-7; R2a y R2b son (i) independientemente H, alquilo C1-7, -(CH2)rN(R1a)2, hidroxialquilo C1-7, -CH2SH, -(CH2)S(O)pMe, - (CH2)3NHC(>;=NH)NH2, (1H-indol-3-il)metilo, (1H-indol-4-il)metilo, -(CH2)mC(>;=O)R1b, arilo y aril alquilo