Thionin

Thionin, also known as thionin acetate or Lauth's violet, is a strongly staining metachromatic dye that is widely used for biological staining. Stainsfile entry: Thionin can also be used in place of Schiff reagent in quantitative Feulgen staining of DNA. It can also be used to mediate electron transfer in microbial fuel cells.

Thionins can also refer to a family of peptides found solely in higher plants. Typically, a thionin consists of 45-48 amino acid residues. 6-8 of these are cysteine forming 3-4 disulfide bonds. Some thionins have cytotoxic activity and they are therefore interesting in the development of new drugs against cancer with novel action mechanisms.  As of yet, no thionin has ever been developed into an anti-cancer drug.

Notes and references
Thionine Tionin