[Problem] The present invention addresses the problem of providing a novel compound. The present invention also addresses the problem of providing an OCT3 detection agent or an OCT3 activity inhibitor, which comprises the novel compound.
[Solution] A compound represented by formula (A), a pharmaceutically acceptable salt thereof, or a pharmaceutically acceptable solvate thereof.
R
1
-R
2
-R
3
-R
4
(A)