Protoanemonin is a toxin

Toxin

A toxin is a poisonous substance produced within living cells or organisms; man-made substances created by artificial processes are thus excluded...

 found in all plants of the buttercup family (Ranunculaceae). On maceration, for example when the plant is wounded, it is produced by an enzymatic process from the glucoside

Glucoside

A glucoside is a glycoside that is derived from glucose. Glucosides are common in plants, but rare in animals. Glucose is produced when a glucoside is hydrolysed by purely chemical means, or decomposed by fermentation or enzymes....

 ranunculin

Ranunculin

Ranunculin is an instable glucoside found in plants of the buttercup family . On maceration, for example when the plant is wounded, it is enzymatically broken down into glucose and the toxin protoanemonin....

. It is the lactone

Lactone

In chemistry, a lactone is a cyclic ester which can be seen as the condensation product of an alcohol group -OH and a carboxylic acid group -COOH in the same molecule...

 of 4-hydroxy-2,4-pentadienoic acid.

A wounded plant releases the substance, causing itch, rashes or blistering on contact with the skin or mucosa. Ingesting fresh Ranunculaceae can lead to nausea

Nausea

Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...

, vomiting, dizziness

Dizziness

Dizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....

, spasm

Spasm

In medicine a spasm is a sudden, involuntary contraction of a muscle, a group of muscles, or a hollow organ, or a similarly sudden contraction of an orifice. It is sometimes accompanied by a sudden burst of pain, but is usually harmless and ceases after a few minutes...

s, or paralysis

Paralysis

Paralysis is loss of muscle function for one or more muscles. Paralysis can be accompanied by a loss of feeling in the affected area if there is sensory damage as well as motor. A study conducted by the Christopher & Dana Reeve Foundation, suggests that about 1 in 50 people have been diagnosed...

.

When drying the plant, protoanemonin comes into contact with air and dimerizes to anemonin

Anemonin

Anemonin is a compound found in plants of the buttercup family . It is the dimerization product of the toxin protoanemonin and is easily hydrolysed to a dicarboxylic acid....

, which is further hydrolyzed to a non-toxic carboxylic acid

Carboxylic acid

Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...

.

Biological pathway

	ranunculin Ranunculin Ranunculin is an instable glucoside found in plants of the buttercup family . On maceration, for example when the plant is wounded, it is enzymatically broken down into glucose and the toxin protoanemonin....
↓ – glucose Glucose Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...	(maceration Maceration Maceration may refer to:* Maceration , in food preparation* Maceration , a step in wine-making** Carbonic maceration, a wine-making technique* Maceration , in sewage treatment* Maceration , a method of preparing bones... , enzymatically)
	protoanemonin
↓ dimerization	(air or water contact)
	anemonin Anemonin Anemonin is a compound found in plants of the buttercup family . It is the dimerization product of the toxin protoanemonin and is easily hydrolysed to a dicarboxylic acid....
↓ hydrolyzation