7-Amino-indole compounds (I) are new. 7-Amino-indole compounds of formula (I) and their salts, organic or inorganic acid or base, or their optical or geometrical isomers and/or solvates such as hydrates, are new. R1 : H, or linear or branched 1-6C-alkyl or branched 3-6C-alkyl (both optionally interrupted with one or more O or -N(R7)-, and/or optionally substituted with one or more radicals comprising OH or N(R7)(R8))； R2, R3 : H, linear 1-6C-alkyl or branched 3-6C-alkyl, -C(O)-O-R, -O-C(O)-R, carboxy, -C(O)-N(R7)(R8) or -N(R7)-C(O)-R8； R : linear 1-6C-alkyl or branched 3-6C-alkyl； R4 : linear or branched 1-6C-alkyl or branched 3-6C-alkyl (both optionally interrupted with one or more O or -N(R7)-, and/or optionally substituted with one or more radicals comprising OH or N(R7)(R8)), or 1-10C-alkoxy, (poly)hydroxy-1-10C-alkoxy or (poly)-1-10C-alkoxy-1-10C-alkyloxy, where the alkoxy groups are alkyloxy groups in which part of the alkyl is linear 1-10C-alkyl or branched 3-10C-alkyl, halo, -C(O)-OH, -C(O)-O-R, -O-C(O)-R, -C(O)-N(R7)(R8) or -N(R7)-C(O)-R8 or -(O) p-Ak-N(R9)(R10)； Ak : divalent alkylene radical, or linear 1-8C-alkyl or branched 3-8C-alkyl (both optionally interrupted with one or more O or -N(R7)-)； R5-R8 : linear 1-6C-alkyl or branched 3-6C-alkyl (both optionally substituted by one or more hydroxy), or H； either R9, R10 : H or linear 1-10C-alkyl or branched 3-10C-alkyl； or R9+N+R10 : 5 or 6 membered heterocyclic chain, optionally saturated, optionally aromatic and optionally containing another heteroatom, such as oxygen or a N(R7)-, preferably heterocycle comprising imidazolyl, pyrrolidino, morpholino, piperidino or piperazino such as 4-(hydroxy)(1-6C)-alkyl-piperazino； and p : 0 or 1 (preferred). Independent claims are included for: (1) the preparation of (I)； (2) compounds comprising substituted 7-nitro-1H-indole compounds of formula (a4) or (a6), 7-nitro-2,3-dihydro-1H-indole compounds of formula (a14)； (3) a composition comprising (I) in a medium； (4) dy
