The present invention provides nitrogen-containing heterocyclic
derivatives represented by the general formula: ##STR00001## wherein
X.sup.1 and X.sup.3 independently represent N or CH; X.sup.2 represents N
or CR.sup.2; X.sup.4 represents N or CR.sup.3; and with the proviso that
one or two of X.sup.1, X.sup.2, X.sup.3 and X.sup.4 represent N; R.sup.1
represents a hydrogen atom, a halogen atom, a lower alkyl group, a lower
alkoxy group, a lower alkylthio group, a lower alkoxy-substituted (lower
alkyl) group, a lower alkoxy-substituted (lower alkoxy) group, a lower
alkoxy(lower alkoxy)-substituted (lower alkyl) group, a cyclic lower
alkyl group, a halo(lower alkyl) group or a group represented by the
general formula: HO-A- wherein A represents a lower alkylene group, a
lower alkyleneoxy group or a lower alkylenethio group; R.sup.2 represents
a hydrogen atom, a halogen atom, a lower alkyl group, a cyclic lower
alkyl group, a lower alkoxy group, an amino group, a (lower acyl)amino
group, a mono(lower alkyl)amino group or a di(lower alkyl)amino group;
and R.sup.3 represents a hydrogen atom or a lower alkyl group, or
pharmaceutically acceptable salts thereof, or prodrugs thereof which are
useful as agents for the prevention or treatment of a disease associated
with hyperglycemia such as diabetes, diabetic complications or obesity,
pharmaceutical compositions comprising the same, and pharmaceutical uses
and production intermediates thereof.