What is the pharmaceutical importance of alkaloids

AlkaloidsAlkaloids are a heterogeneous group of natural organic molecules with basic properties that contain nitrogen atoms. They are usually derived from amino acids and are mainly found in plants, but also in animals, fungi and microorganisms. Alkaloids have been used medicinally for thousands of years and play a prominent role in pharmacy. Well-known examples are morphine, cocaine, atropine, quinine, nicotine and caffeine.

synonymous: alkaloid


Alkaloids and their derivatives are contained as active ingredients in numerous medicinal products. They have been used medicinally for thousands of years, for example opium with morphine or coca leaves with cocaine. In 1805 the German pharmacist Friedrich Sertürner extracted a pure alkaloid with morphine for the first time.

Structure and properties

Alkaloids are a heterogeneous group of natural organic molecules with a low molecular weight (Small Molecules) that contain nitrogen atoms (N) and have a basic character. The nitrogen is usually located in a heterocyclic ring system, but there are exceptions, the so-called protoalkaloids.

Alkaloids are usually derived from amino acids such as ornithine, lysine, phenylalanine, tyrosine and tryptophan and are among the secondary metabolites. The name comes from "alkaline", which means basic. The suffix -oid stands for similar.

Alkaloids typically have a bitter taste. They form salts with acids through protonation. When adding a base, the free alkaloid base is created by deprotonation of the nitrogen.

In contrast to other substance classes such as carbohydrates or proteins, alkaloids occur naturally only in selected organisms. Often they are plants, but also animals, microorganisms (e.g. tetrodotoxin) or fungi (e.g. ergot, "magic mushrooms" such as Psilocybe semilanceata). They are not always synthesized by the living beings themselves, some are also absorbed and enriched.

Among other things, they protect plants and animals from predators. Many alkaloids, such as nicotine and caffeine, have insecticidal properties.

Alkaloids are used in pharmacy as medicinal drugs (e.g. opium), as pure substances (e.g. morphine), as extracts (e.g. belladonna extract) and for the production of derivatives (e.g. atropine).

It should be added that many of the general properties do not apply to all representatives.


Alkaloids have a variety of pharmacological properties. Often they are already very active in small doses.

application areas

Alkaloids and their derivatives are used very widely in medicine, for example for pain, cancer, cold symptoms, flu, fatigue, migraines, gout, asthma and COPD. You have played a central role in drug discovery in pharmacy history.

The best-known intoxicants, for example morphine, heroin, cocaine, nicotine and various hallucinogens such as psilocybin or mescaline belong to the alkaloids.


The types of application for alkaloids are diverse. They are applied both topically and systemically.


Alkaloids are often misused as intoxicants, stimulants, poisons and doping agents.

Active ingredients

Tens of thousands of alkaloids exist. Some important representatives are listed below. Their name ends with the suffix -in:

Benzylisoquinoline alkaloids:

Catharanthus alkaloids:

Cinchona alkaloids:

Ephedra alkaloids:

Ipecacuanha alkaloids:

Kath alkaloids:

Purine alkaloids:

Indole alkaloids:

Nicotiana alkaloids:

Opium alkaloids:

Jaborandi alkaloids:

Piperidine alkaloids:

Pyrrolizidine alkaloids:

Rauvolfia alkaloids:

Steroid alkaloids:

Solanum alkaloids:

Terpenoid alkaloids:

Tropane alkaloids:

unwanted effects

Many alkaloids have potent pharmacological properties and a narrow therapeutic index. An overdose can be life threatening. Accordingly, they must be handled with care.

Alkaloids misused as intoxicants often lead to addiction and addiction, often with destructive consequences.

Alkaloids are also found in many poisonous plants and can cause poisoning. Some representatives are teratogenic.

see also

Nitrogen, bases, amino acids, heterocycles, intoxicants

  • Medicinal product information (CH)
  • European Pharmacopoeia PhEur
  • Specialist literature
  • Phytotherapy textbooks

Conflicts of Interest: None / Independent. The author has no relationships with the manufacturers and is not involved in the sale of the products mentioned.

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This article was last changed on 9/29/2020.
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