The object of the invention is to provide an excellent compound as a drug. The invention relates to a heterocyclic compound shown by the following formula: A—B—D—E  [1] wherein A is heteroaryl or its oxide; B is ethenylene; D is optionally substituted phenylene; and E is a group of the formula:  wherein G is optionally substituted phenyl; and R is heteroaryl or heteroarylmethyl, or a group of the formula: wherein n is an integer of 1 to 5; R5 and R6 are same or different and are independently selected from the group consisting of hydrogen, C1—C6 alkyl, hydroxyalkyl, aminoalkyl; or R5 and R6 taken together with the adjacent nitrogen atom may form 5- to 7-membered cyclic amino group for —NR5R6 or a salt thereof.