The inventive subject matter relates to compounds, pharmaceutical compositions, and kits containing a heterocyclic compound represented by the formula (I) ##STR00001## wherein R is an alkyl group optionally having substituent(s) etc., X is an amino group optionally having substituent(s), Y.sub.1 and Y.sub.2 are nitrogen atoms etc., an isomer or solvate thereof or a pharmaceutically acceptable salt thereof as an active ingredient.