ANTITUMOUR TETRACYCLIC COMPOUNDS

摘要

The present invention relates to heterocyclic compounds which have been found to have anti-tumour activity. More specifically, the invention concerns compounds of formula (I), wherein A is (a), (b), (c) or (d), X is O, S, SO, SO2, CH2, CO or NR<7>, wherein R<7> is H, alkyl, aralkyl, aryl, alkenyl, acyl, alkynyl, sulphonyl or substituted sulphonyl; Y is O, S, SO, SO2, CH2, CO or NR<7>, with the proviso that Y is not O when X is O; methods for their preparation, pharmaceutical formulations containing them and their use as anti-tumour agents. The compounds have low toxicity against normal cell lines whilst exhibiting anti-tumour cell activity.