What is "isatogen"

Isatogen \I*sat"o*gen\, n. [Isatin + -gen.] (Chem.) A complex nitrogenous radical, C8H4NO2, regarded as the essential residue of a series of compounds, related to isatin, which easily pass by reduction to indigo blue. -- I*sat`o*gen"ic, a.

n. (context organic compound English) A complex nitrogenous radical, C₈H₄NO₂, related to isatin.