Brucine vs. Strychnine

What's the Difference?

Brucine and strychnine are both alkaloid compounds that are derived from the seeds of the Strychnos nux-vomica tree. While they share some similarities, they also have distinct differences. Both compounds are highly toxic and act as central nervous system stimulants, but strychnine is known to be more potent and lethal. Brucine is less toxic and has been used in medicine as a muscle relaxant and antimalarial agent. In terms of their chemical structures, brucine has a methoxy group attached to its aromatic ring, while strychnine has a double bond in its ring structure. Overall, while both compounds are toxic, strychnine is more potent and brucine has some medicinal applications.


Chemical FormulaC23H26N2O4C21H22N2O2
Molecular Weight394.46 g/mol334.43 g/mol
AppearanceWhite crystalline powderWhite crystalline powder
SolubilitySlightly soluble in waterSlightly soluble in water
TasteBitterExtremely bitter
ToxicityHighly toxicHighly toxic
UsesUsed in chemical research and as a pesticideUsed in chemical research and as a pesticide

Further Detail


Brucine and strychnine are two alkaloids that belong to the same family of compounds known as strychnos alkaloids. While they share some similarities in terms of chemical structure and toxicity, they also exhibit distinct characteristics that set them apart. This article aims to explore and compare the attributes of brucine and strychnine, shedding light on their properties, uses, and potential risks.

Chemical Structure

Both brucine and strychnine are derived from the seeds of the Strychnos nux-vomica tree, a plant native to Southeast Asia. Chemically, they are both indole alkaloids, meaning they contain an indole ring structure. However, their specific chemical structures differ slightly.

Brucine, with the chemical formula C23H26N2O4, consists of two indole rings connected by a central carbon chain. It also contains two hydroxyl groups, which contribute to its solubility in water. On the other hand, strychnine, with the chemical formula C21H22N2O2, has a single indole ring and lacks the hydroxyl groups found in brucine.


Both brucine and strychnine are highly toxic substances, acting as potent neurotoxins. They exert their toxic effects by blocking the action of the neurotransmitter glycine in the central nervous system, leading to severe muscle spasms and convulsions.

However, strychnine is generally considered to be more toxic than brucine. Even small doses of strychnine can be lethal, with a reported LD50 (lethal dose for 50% of the population) of around 1-2 milligrams per kilogram of body weight in humans. In contrast, brucine is relatively less toxic, with an LD50 of approximately 10-20 milligrams per kilogram of body weight.

It is worth noting that both brucine and strychnine are classified as Schedule I substances by the United States Drug Enforcement Administration (DEA) due to their high potential for abuse and severe health risks.


Historically, brucine and strychnine have found applications in traditional medicine, particularly in Ayurvedic and Chinese medicine. They were used as stimulants, tonics, and remedies for various ailments, including digestive disorders and respiratory problems.

However, due to their high toxicity, the medical use of brucine and strychnine is extremely limited today. In rare cases, they may be used as a last resort in the treatment of certain conditions, such as poisoning caused by other substances. Additionally, they have been employed in scientific research as tools to study the nervous system and muscle function.

Pharmacological Effects

Both brucine and strychnine exert their effects on the central nervous system, specifically by antagonizing glycine receptors. By blocking glycine, they disrupt the inhibitory signals in the spinal cord, leading to uncontrolled muscle contractions and spasms.

However, there are some differences in the pharmacological effects of brucine and strychnine. Brucine has been found to have additional actions on other neurotransmitter systems, such as the cholinergic and dopaminergic systems. These additional effects may contribute to its distinct pharmacological profile compared to strychnine.

Adverse Effects

As highly toxic substances, both brucine and strychnine can cause severe adverse effects if ingested or absorbed into the body. The most notable adverse effect is the development of muscle spasms and convulsions, which can progress to respiratory failure and death if left untreated.

Other common adverse effects include increased heart rate, elevated blood pressure, anxiety, restlessness, and gastrointestinal disturbances. In severe cases, the convulsions can lead to rhabdomyolysis, a condition characterized by the breakdown of muscle tissue and the release of toxic substances into the bloodstream.


In conclusion, brucine and strychnine are two alkaloids derived from the Strychnos nux-vomica tree that share similarities in their chemical structure and toxicity. However, they also exhibit distinct attributes, such as differences in their specific chemical structures, toxicity levels, pharmacological effects, and adverse effects.

While both substances are highly toxic and have limited medical uses, strychnine is generally considered more toxic than brucine. It is crucial to handle these substances with extreme caution and to avoid any exposure or ingestion due to their potential health risks.

Further research is needed to fully understand the mechanisms of action and potential therapeutic applications of brucine and strychnine. However, given their high toxicity, it is unlikely that they will become widely used in medicine in the future.

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