PROBLEM TO BE SOLVED: To provide a GPR40 activator comprising a compound having a novel GPR40 agonistic action or a salt thereof or a solvate thereof as an active ingredient, particularly an insulin secretion promoter, a preventive and / or therapeutic agent for diabetes, obesity, etc. . In the formula, p is 0 to 4; j is 0 to 3; k is 0 to 2; ring A is a specific cyclic group; ring B is a benzene ring or a pyridine ring. , Pyrimidine ring; X is —CH 2 —, O, —S (O) i — (i is 0 to 2), —NR 7 —; R 1 to R 6 are specific groups) or a salt thereof Or a solvate thereof. [Selection figure] None【課題】新規なGPR40アゴニスト作用を有する化合物またはその塩またはそれらの溶媒和物等を有効成分とするGPR40活性化剤、とりわけインスリン分泌促進剤、糖尿病、肥満等の予防及び/または治療剤の提供。【解決手段】式(I)【化1】(式中、pは0~4;jは0~3;kは0~2;環Aは特定の環状基;環Bはベンゼン環、ピリジン環、ピリミジン環;Xは-CH2-、O、-S(O)i-(iは0~2)、-NR7-;R1~R6は特定の基を示す)で表される化合物、またはその塩またはそれらの溶媒和物。【選択図】なし