| abstract |
The present invention provides a compound that specifically binds to a zinc ion, has a sufficiently high fluorescence intensity, and has a fluorescence spectrum that is sufficiently shifted so that ratio measurement is possible. A coumarin derivative represented by the general formula (I) or a salt thereof. In the formula (I), X 1 is a hydrogen atom, X 2 is a hydrogen atom or a lower alkyl group, X 3 is a hydrogen atom, etc. Y is a group represented by the formula — (CH 2 ) n — Here, n is an integer of 1 to 3, and W is a group represented by —OH, —NH 2 , or the like. [Selection figure] None |