[Problem] To provide compounds useful as preventives or remedies for circular system disorders, nervous system disorders, metabolic disorders, reproduction system disorders, digestive system disorders, neoplasm, infectious diseases, etc., or as herbicides. [Means for Solution] A long-chain fatty acyl elongase inhibitor comprising, as the active ingredient thereof, a compound or a pharmaceutically-active salt thereof of a formula (I): [wherein W represents a hydrogen atom, a C 1-6 alkyl, etc.； X represents an aryl, a heteroaryl, etc.； n indicates 0 or 1； Z represents a hydrogen atom, a C 1-6 alkyl, etc.； A 1 , A 2 , A 3 and A 4 each independently represent CH or N].
