Pyrazole-based cyanine dye

Abstract

PROBLEM Provided is a novel cyanine dye derivative with a pyrazole skeleton and an indole skeleton, having high sensitivity performance in a shorter wavelength region as compared with a conventional optical system, and showing high water solubility. SOLUTION The invention provides (1) a compound represented by the following general formula [50] and a salt thereof: [wherein Rto Reach independently represent a substituted or unsubstituted alkyl group which may have an amide bond; Rto Reach independently represent alkyl group, alkenyl group, alkynyl group, aryl group, alkoxy group, aryloxy group, alkylthio group, arylthio group, alkylsulfonyl group, arylsulfonyl group, carbamoyl group, sulfamoyl group, ureido group or amino group, those groups being able to have substituents; a group represented by the general formula [2]:—COOR  [2](wherein Rrepresents hydrogen atom, Cto Calkyl group, alkali metal atom, organic ammonium ion, ammonium ion or anion); a group represented by the general formula [3]:—SOR  [3](wherein Rrepresents hydrogen atom, alkali metal atom, organic ammonium ion, ammonium ion or anion), halogen atom, aromatic heterocyclic thio group, hydrogen atom, hydroxyl group, cyano group, formyl group, thiol group or nitro group; Rrepresents hydrogen atom, or alkyl group, alkenyl group, alkynyl group or aryl group, those groups being able to have substituents; and n represents an integer of from 0 to 3, provided that any of Rand R, Rand R, Rand R, and Rand Rmay form a bivalent group with a group selected from —O— group, —S— group, —COO— group and groups represented by the general formulae [52] to [54]: (wherein Rrepresents hydrogen atom, alkyl group, alkenyl group or aryl group, those groups being able to have substituents), and substituted or unsubstituted alkylene group; and in the case where said bivalent group is formed, at least one of Rto R, along with the bivalent group formed by any of Rand R, Rand R, Rand R, and Rand R, has the group represented by the general formula [2], the group represented by the general formula [3], amino group, hydroxyl group, thiol group or formyl group; and in the case where said bivalent group is not formed, at least one of Rto Rhas the group represented by the general formula [2], the group represented by the general formula [3], amino group, hydroxyl group, thiol group or formyl group]; (2) a labeled compound obtained by subjecting the above compound to direct or indirect binding to a substance to be labeled, and (3) a method for labeling a substance to be labeled, comprising subjecting the above compound to direct or indirect binding to the substance to be labeled.