Alkaloids: contain a N-containing heterocycle

Alkaloids are derived from various amino acids : ornithine, lysine, phenylalanine etc.

Over 3000+ known alkaloids exist:
Examples: Nicotine, caffeine, morphine, colchcine, ergots, LSD, strychnine, quinine, resperine

Alkaloids have many effects on humans and other animals:

Known effects on mammals:

Cyanogenic glycosides-These compounds are only toxic when they are broken down by the organism's enzymes and release HCN or prussic acid.
  • HCN attacks the cytochrome system, interfering with the electron transfer necessary for the production of a H+ gradient in metabolism. This leads to oxygen starvation and rapid death.
  • Cyanogenic glycosides are also toxic due to the release of nitrite.
Glc-O-(CH2)3 NO2 -------->NO2-
The nitrite released substitutes for the oxygen on hemoglobin, thus interfering with the transfer of oxygen in the blood. This compound is especially harmful to cattle, but the human nervous system doesn't seem to take as much damage from this compound.

Glucsinolates-These mustard oil glycosides, often found in wild Brassica can cause gastroenteritis, salivation, diarrhea, and irritation of the mouth. When these compounds are modified, they can cause hyperthyroidism.


Specific examples of alkaloids include:


Steroid alkaloids i.e.. Zygacine from the Death Camus plant induces vomiting, diarrhea, decreased heart rate, gastroenteritis, subnormal temperature- (simulated death state) - use din voodoo practices

Indole ring i.e.. Vincristine: reduced white blood count used in leukemia from the Periwinkle plant


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