A compound of the formula (I): wherein ring A is a carbocyclic group, R1
is hydrogen or a halogen atom or a lower alkyl group, R2 is a
di(lower)alkylamino group or N-containing heterocyclic group, among which
the N-containing heterocyclic group may be substituted with one or more
substituent(s), Y is an oxygen or sulfur atom, n is an integer from 0 to
2, and m is an integer from 0 to 4, or its prodrug, or their salt which
has poly(adenosine 5'-diphospho-ribose)polymerase inhibiting activity. 1
