2-substituted benzothiazolyl-3-substituted phenyl-5-substituted sulfonated phenyl-2H-tetrazolium salt, reagent for biological component concentration measurement containing said salt, and biological component concentration measurement method using said salt

A 2-substituted benzothiazolyl-3-substituted phenyl-5-substituted sulfonated phenyl-2H-tetrazolium salt represented by the following Formula (1):

• wherein in Formula (1), R1 represents any one selected from the group consisting of a hydrogen atom, a hydroxyl group, a methoxy group, and an ethoxy group;
• R2 represents any one selected from the group consisting of a nitro group, —OR4, and a carboxyl group;
• R3 represents a hydrogen atom, a methyl group, or an ethyl group, while at least one is a methyl group or an ethyl group;
• R4 represents a methyl group or an ethyl group;
• m represents the number of sulfo groups (—SO3−) bonded to the phenyl group at the 5-position of the tetrazole skeleton, and is 1 or 2;
• n represents the number of R2 bonded to the phenyl group at the 3-position of the tetrazole skeleton, and is an integer from 0 to 2;
• p represents the number of sulfo groups (—SO3−) bonded to the phenyl group at the 3-position of the tetrazole skeleton, and is 0 or 1;
• n+p is 1 or greater;
• q is 1 or 2;
• when q is 2, the OR3's are disposed adjacently to each other and may be bonded to each other and forma ring;
• and X represents a hydrogen atom or an alkali metal atom.