Bisindole Alkaloids
More than 200 of dimeric indole (bisindole) alkaloids are known. They are produced in living organisms through dimerization of monomeric indole bases, in the following reactions:
- Mannich reaction (voacamine)
- Michael reaction (villalstonine)
- Condensation of aldehydes with amines (toxiferine, calebassine
- Oxidative coupling of tryptamines (calicantine);
- Splitting of the functional group of one of the monomers (vinblastine, vincristine).
| Voacamine | Villalstonine | Toxiferine | Vinblastine |
Apart from bisindole alkaloids, dimeric alkaloids exist which are formed via dimerization of the indole monomer with another type of alkaloid. An example is tubulosine consisting of indole and isoquinoline fragments.
Read more about this topic: Indole Alkaloids
Famous quotes containing the word alkaloids:
“If an addict who has been completely cured starts smoking again he no longer experiences the discomfort of his first addiction. There exists, therefore, outside alkaloids and habit, a sense for opium, an intangible habit which lives on, despite the recasting of the organism.... The dead drug leaves a ghost behind. At certain hours it haunts the house.”
—Jean Cocteau (1889–1963)