Indigo

   Fig 1. Indigo plant

     My favorite organic molecule is Indigo (dye) because of it's highly coveted nature and it's coloration. The dye was very widely used during the Middle Ages and up until the 1900s when a synthetic indigo was created. While most indigo producing plants were cultivated in India and Guatemala, the dye has been used in many cultures throughout the world, especially in textiles and paintings of spiritual significance. Because of how high trade values were, Indigo was referred to as "Blue Gold".                                                          

    It's most common source is plants of the tropical Indigofera genus, which has over 300 species. Though the dye has a gorgeous blue color, the extracted chemical is actually colorless until treated and fermented. The dye is applied easily to most fabrics such as cotton and silk, as well as used on hair. Most indigo dye used today is synthetic in origin, but natural indigo has been a highly coveted dye since the Crusades when it was first brought over to Europe from the Middle East and South Asia.

Fig 2. Organic Structure of Indigo

     Indigo is related to the amino acid Tryptophan and is synthesized not only in plants, but also in humans. This production can lead to a recessive disease in people who are unable to properly process the chemical that causes urine to be blue.

The structure of indigo includes several Carbon rings and is stabilized by Hydrogen Bonds between the H and O atoms that are attached to the rings.



Sources:
https://www.lib.umn.edu/bell/tradeproducts/indigo
http://www.chemexplore.net/indigo.htm
http://caliban.mpiz-koeln.mpg.de/mavica/index.html