indigo blue

A dark red crystalline substance, isomeric with and resembling indigo blue, and obtained from isatide and dioxindol.

A substance isomeric with, and resembling, indigo blue, and accompanying it as a side product, in its artificial production.

An orange-red crystalline substance, C8H5NO2, obtained by the oxidation of indigo blue

A body identical with indigo blue, occasionally found in the urine in degeneration of the kidneys