Indenoindolone derivatives (I), their isomers and salts with acids and bases are new. Indenoindolone derivatives (I), their isomers and salts with acids and bases are new; R = H, alkyl (optionally substituted by carboxy, alkoxycarbonyl, or NR10R11), or alkenyl; R1-R8 = H, alkyl (optionally substituted by aryl, carboxy or alkoxycarbonyl), OH, acyloxy, NR12R13, carboxy, alkoxy (optionally substituted by aryl or NR14R15), alkenyloxy, or to adjacent groups R1-R8 = 1 or 2C alkylenedioxy; R9 = H, aryl, heteroaryl or alkyl (optionally containing one or more unsaturations and optionally substituted by one or more aryl, heteroaryl, 3-8C cycloalkyl, CN, or NR17R18 groups); X = O or NR16; R10, R11, R14, R15, R17, R18 = alkyl; NR10+R11, NR14+R15, NR17+R18 = nitrogen heterocycle; R12, R13 = H, alkyl, or NR14R15; R16 = H, alkyl, aryl, or aryl alkyl. Where alkyl, alkoxy, acyloxy, alkenyl and alkenyloxy groups have up to 6 C atoms, aryl is defined as phenyl, biphenyl, or naphthyl (optionally substituted by one or more halogen, alkyl, alkenyl, alkoxy, phenoxy, nitro, CN, amino, mono- and di-alkylamino or 1-2C alkylenedioxy groups) and heteroaryl groups may be mono- or bicyclic of 5-12 members with 1-3 heteroatoms (O, N, S) and optionally substituted by halogen, alkyl, OH, alkoxy, polyhaloalkyl, amino, mono- and di-alkylamino groups, and nitrogen heterocycles are monocyclic having 5-7 members including 1-3 heteroatoms, one of which is N and the others may be O, N, or S. An Independent claim is also included for the preparation of (I).