The present invention relates to provision of a novel compound that has an activity of promoting insulin secretion from pancreatic ² cells and thus is useful as a prophylaxis and/or therapeutic agent for diseases caused by hyperglycemia such as diabetes mellitus, and the compound represented by the following formula (1): wherein one of A and B represents a nitrogen atom and the other represents a nitrogen atom or CR 10 , X represents an oxygen atom, a sulfur atom or - (CH 2 )n-N(R 12 ) -, Y represents an oxygen atom, a sulfur atom or -N(R 13 )-, and R 1 to R 9 each represent a hydrogen atom or another substituent, or a salt thereof, or a solvate of the compound or the salt.
