March 06, 2012
Image of Skatole 3D Image of Skatole

Skatole, or 3-methylindole, is a foul-smelling constituent of mammalian feces; it is produced by the decomposition of tryptophan in the digestive tract. It has a floral aroma at low concentrations, contributing to the pleasant smell of flowers such as jasmine and orange blossoms. Skatole also occurs naturally in substances as diverse as beetroot and coal tar.

MOTW update: 
October 29, 2018

Skatole is what causes mammalian feces to smell bad. Recently, scientists in China, Singapore, and the United States reported the discovery of the enzyme, indoleacetate decarboxylase, which bacteria use to convert tryptophan to skatole in the gut.


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