| abstract |
There are disclosed, as novel compounds, pyrrolo [2,1-c][1,4] benzodiazepine (PBD) dimers of formula (I) where the PBD tricyclic structures may contain additional substituents in one or more of the 1, 2, 3, 6, 7, 9 and 11-positions and the C rings may optionally contain at least one further hetero ring atom, X is -O-, -S- or -NH-, and R1 is an alkylene chain containing from 3 to 12 carbon atoms, which chain may, if desired, be interrupted by one or more hetero-atoms and which chain may, if desired, contain one or more carbon-carbon double or triple bonds. These compounds are cytotoxic and have shown in vitro activity against a range of carcinoma cell lines. |