Observations on the manner of manufacturing indigo in the Southern Provinces of India; with some remarks on its chemical changes and combinations

From Tyrian Purple to Kinase Modulators: Naturally Halogenated Indirubins and Synthetic Analogues

“…Indirubin (1), indigo (2), and isoindigo (3) are the core representatives of a rather small category of bisindole alkaloids referred to as indigoids (l " Fig. 1).…”

“…The main production and trade centers were Albi/Toulouse in France, Somerset in Great Britain, Thüringen in Germany, and Florence in Italy. In India, Pakistan, South America, and Africa, Indigofera tinctoria (Fabaceae) was cultivated and processed for the production of indigo dye [2] while the Mayas have combined indigo and natural clays to prepare the pigment Maya blue [3]. In China, Korea, and Japan, Polygonum tinctorium (Polygonaceae) was used for the preparation of indigo dye, although the species was considered poor in terms of indigo content [4].…”

“…Structures of indirubin (1), indigo(2), and isoindigo(3). The Tyrian purple producing mollusk Hexaplex trunculus (Muricidae) and details of the fresco entitled "The Saffron Gatherers" located in the archaeological site of Akrotiri, Thera, Greece.…”