Compound Class

Alkaloids

Nitrogen-containing, often bitter and physiologically potent compounds — the group behind many of the strongest plant medicines and poisons.

401 Constituents8 Subclasses109 Source herbs

Overview

What Are Alkaloids?

Alkaloids are nitrogen-containing compounds produced by plants and other organisms. Most carry a basic nitrogen atom, usually held within a ring structure, and are biosynthesized from amino acids such as tyrosine, tryptophan, ornithine and lysine.

They are often intensely bitter and physiologically active. It is this combination of chemical reactivity and biological potency that gives alkaloids an unusually large role in medicine, toxicology and pharmacology.

Where Alkaloids Occur

Alkaloids are unevenly distributed across the plant kingdom. Most families produce few or none, while certain lineages accumulate them in abundance.

Nightshades (Solanaceae)

Poppies (Papaveraceae)

Legumes (Fabaceae)

Coffee and related plants (Rubiaceae)

Tea and related plants (Theaceae)

As a result, much of alkaloid chemistry is concentrated within a relatively small number of botanical families.

Defining the Class

“Alkaloid” is a practical rather than a perfectly strict chemical category. Compounds are generally classed as alkaloids when they:

Contain nitrogen
Behave as bases
Occur naturally
Produce significant physiological effects

Not every alkaloid meets all of these criteria, and some simple nitrogen-containing compounds sit at the boundary of the class.

Pharmacological Importance

Alkaloids include some of the most powerful natural compounds known. Members of the class act as stimulants, analgesics, sedatives, antimalarials, muscle relaxants and anesthetic adjuncts.

Their activity usually comes from interacting strongly with receptors, ion channels, enzymes or neurotransmitter systems — the same targets much of modern pharmacology is built around.

Toxicity & Safety

Toxicity matters more here than in any other compound class. Alkaloids include both major medicines and some of the deadliest plant poisons, sometimes the same compound at different doses.

Many have a narrow therapeutic window, meaning the difference between an effective dose and a harmful one can be small. They therefore require more careful identification, preparation and dosing than most other phytochemical classes.

Constituents

All Alkaloids

401 total Filter alkaloids

(S)-scoulerine 2 herbs 11-Hydroxypolyneuridine 1 herb 11-Methoxyquindoline 1 herb 14-Deacetylnudicauline 1 herb 17-Oxosparteine 1 herb 2-methyl-1,2,3,4-tetrahydro-beta-carboline 1 herb 2-methyl-6-methoxy-1,2,3,4-tetrahydro-beta-carboline 1 herb 3-Angeloylzygadenine 1 herb 3-Methoxytyramine 1 herb 3-Veratroylzygadenine 1 herb 4-Hydroxygalegine 1 herb 4-methylcurine 1 herb 5-Bromo-DMT 5-MeO-DMT 4 herbs 7-Hydroxymitragynine Care 1 herb 7-methylxanthine 1 herb 9-Hydroxycorynantheidine 1 herb

Acetylcholine 2 herbs Achillein 1 herb Aconitine 1 herb Aegeline 1 herb agmatine 1 supp Ajmalicine 2 herbs Akuammidine 1 herb

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Source Plants

Herbs Containing Alkaloids

109 herbs

Plants in the materia medica documented to carry alkaloids, with the compounds each one is listed for. The bar counts how many DISTINCT alkaloids are on record for a plant, relative to the best-documented — it measures breadth of record, not potency, so a plant with one well-studied compound can outrank a richer source that has simply been analysed less. Where a measured concentration is on record it is quoted inline; most entries have none yet.