A compound useful as an AMPK-activating agent is provided. A compound represented by formula (I) (wherein X represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted cycloalkenyl group or a substituted or unsubstituted heterocyclyl group R1 represents a hydrogen atom, a halogen atom, a cyano group, a nitro group, a carboxy group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted acyl group, a substituted or unsubstituted carbamoyl group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted alkylsulfinyl group, a substituted or unsubstituted alkylsulfonyl group or a substituted or unsubstituted alkyloxycarbonyl group R2 represents a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted cycloalkenyl group, a substituted or unsubstituted heterocyclyl group or the like R3 represents a halogen atom, a hydroxy group, a cyano group, a nitro group, a carboxy group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted cycloalkenyl group, a substituted or unsubstituted heterocyclyl group or the like and R4 represents a hydrogen atom, a halogen atom, a hydroxy group, a cyano group, a nitro group, a carboxy group,
