2H-Indol-2-one, 3-(1,3-dihydro-3-oxo-2H-indol-2-ylidene)-1,3-dihydro- 479-41-4 C.I. 73200 INDIRUBIN Indigo red Indigopurpurin NSC105327 [.DELTA.2,3'-Biindoline]-2',3-dione