Direct yellow 7
The structural formula above was located via the Internet, and is of the major component of the dye, according to Wu and coworkers. It is a fluorescent dye and is a mixture, one component of which demonstrates amyloid. Conn states that thioflavine S is made from primuline by methylation and sulphonation.
R. D. Lillie.
Conn's Biological Stains
Williams & Wilkins, Baltimore, MD., U.S.A.
Wu, C., Wei, J.. Gao. Y and Wang. Y.,
Dibenzothiazoles as novel amyloid-imaging agents,
Bioorganic and Medicinal Chemistry, v15, pp.2789-2796