There has been a need for coelenteramide analogs or the like that produce fluorescent proteins which exhibit different fluorescent characteristics from those of the existing fluorescent proteins. Disclosed is a compound represented by general formula (1) (wherein R1 represents a substituted or unsubstituted aryl, a substituted or unsubstituted arylalkyl, a straight or branched alkyl which may optionally be substituted with an alicyclic group, an alicyclic group or a heterocyclic group; R2 represents hydrogen or —(SO2)R4; R3 represents hydrogen, hydroxyl, methoxy or acetoxy; R4 represents a substituted or unsubstituted aryl, a substituted or unsubstituted arylalkyl or a straight or branched alkyl which may optionally be substituted with an alicyclic group; and X1 represents —C(═S)— or —SO2—).
There has been a need for coelenteramide analogs or the like that produce fluorescent proteins which exhibit different fluorescent characteristics from those of the existing fluorescent proteins. Disclosed is a compound represented by general formula (1) (wherein R
1
represents a substituted or unsubstituted aryl, a substituted or unsubstituted arylalkyl, a straight or branched alkyl which may optionally be substituted with an alicyclic group, an alicyclic group or a heterocyclic group; R
2
represents hydrogen or —(SO
2
)R
4
; R
3
represents hydrogen, hydroxyl, methoxy or acetoxy; R
4
represents a substituted or unsubstituted aryl, a substituted or unsubstituted arylalkyl or a straight or branched alkyl which may optionally be substituted with an alicyclic group; and X
1
represents —C(═S)— or —SO
2
—).