Alkaloids

Products

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

Structure and properties

Alkaloids are a heterogeneous group of natural organic molecules with a deep molecular mass (small molecules), containing nitrogen atoms (N) and having a basic character. The nitrogen is usually in a heterocyclic ring system, but there are exceptions called protoalkaloids. Alkaloids are usually derived from amino acids, such as ornithine, lysine, phenylalanine, tyrosine, and tryptophan, and are secondary metabolites. The name comes from “alkaline,” which means basic. The suffix -oid stands for similar. Alkaloids typically have a bitter taste. With acids, they form salts by protonation. When a base is added, the free alkaloid base is formed by deprotonation of the nitrogen. Unlike other substance classes such as carbohydrates or proteins, alkaloids occur in nature only in selected organisms. Often they are plants, but also animals, microorganisms (e.g. tetrodotoxin) or fungi (e.g. ergot, “magic mushrooms” like ). They are not always synthesized by the living organisms themselves, some are also ingested and enriched. Plants and animals use them, among other things, to protect themselves from predators. Many alkaloids, for example 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 restrictively that many of the general properties do not apply to all representatives.

Effects

Alkaloids have a wide variety of pharmacological properties. They are often strongly active even at low doses.

Indications for use

Alkaloids and their derivatives are widely used in medicine, for example, for pain, cancer, cold symptoms, influenza, fatigue, migraine, gout, asthma, and COPD. They have played a central role in pharmaceutical history for drug discovery. The best-known narcotics, for example, morphine, heroin, cocaine, nicotine, and various hallucinogens such as psilocybin or mescaline belong to the alkaloids.

Dosage

The modes of application for alkaloids are varied. They are applied both topically and systemically.

Abuse

Alkaloids are often abused 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:

  • Papaverine

Catharanthus alkaloids:

  • Vinblastine, vincristine

Cinchona alkaloids:

  • Quinine, quinidine

Ephedra alkaloids:

  • Ephedrine, pseudoephedrine

Ipecacuanha alkaloids:

  • Emetine, Cephaeline

Cath alkaloids:

  • Cathinone

Purine alkaloids:

Indole alkaloids:

Nicotiana alkaloids:

  • Nicotine

Opium alkaloids:

  • Morphine, codeine

Jaborandi alkaloids:

  • Pilocarpine

Piperidine alkaloids:

  • Piperine, coniine

Pyrrolizidine alkaloids:

  • Tussilagin

Rauvolfia alkaloids:

  • Reserpine, ajmaline

Steroid alkaloids:

  • Batrachotoxins
  • Veratrum alkaloids

Solanum alkaloids:

  • Solanine, Tomatine

Terpenoid alkaloids:

  • Aconitine, ryanodine, taxol

Tropane alkaloids:

Adverse effects

Many alkaloids have potent pharmacological properties and a narrow therapeutic range. An overdose can be life-threatening. Accordingly, they must be handled with care. Alkaloids abused as intoxicants often lead to dependence and addiction, often with destructive consequences. Alkaloids are also contained in many poisonous plants and can cause poisoning.Some representatives are teratogenic.