Putrescine is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. T ...

with the formula (CH₂)₄(NH₂)₂. It is a colorless solid that melts near room temperature. It is classified as a diamine. Together with cadaverine, it is largely responsible for the foul odor of

putrefying Putrefaction is the fifth stage of death, following pallor mortis, algor mortis, rigor mortis, and livor mortis. This process references the breaking down of a body of an animal, such as a human, post-mortem. In broad terms, it can be view ...

flesh, but also contributes to other unpleasant odors.

Production

Putrescine is produced on an industrial scale by the

hydrogenation Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organ ...

of succinonitrile. Biotechnological production of putrescine from renewable feedstock has been investigated. A metabolically engineered strain of ''

Escherichia coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus '' Esc ...

'' that produces putrescine at high concentrations in glucose mineral salts medium has been described.

Biochemistry

Spermidine synthase uses putrescine and ''S''-adenosylmethioninamine (decarboxylated ''S''-adenosyl methionine) to produce

spermidine Spermidine is a polyamine compound () found in ribosomes and living tissues and having various metabolic functions within organisms. It was originally isolated from semen. Function Spermidine is an aliphatic polyamine. Spermidine synthase (SP ...

. Spermidine in turn is combined with another ''S''-adenosylmethioninamine and gets converted to

spermine Spermine is a polyamine involved in cellular metabolism that is found in all eukaryotic cells. The precursor for synthesis of spermine is the amino acid ornithine. It is an essential growth factor in some bacteria as well. It is found as a p ...

. Putrescine is synthesized in small quantities by healthy living cells by the action of

ornithine decarboxylase The enzyme ornithine decarboxylase (, ODC) catalyzes the decarboxylation of ornithine (a product of the urea cycle) to form putrescine. This reaction is the committed step in polyamine synthesis. In humans, this protein has 461 amino acids a ...

. Putrescine is synthesized biologically via two different pathways, both starting from arginine. * In one pathway, arginine is converted into

agmatine Agmatine, also known as 4-aminobutyl-guanidine, is an aminoguanidine that was discovered in 1910 by Albrecht Kossel. Agmatine is a chemical substance which is naturally created from the amino acid arginine. Agmatine has been shown to exert modula ...

. The conversion is catalyzed by the enzyme arginine decarboxylase (ADC). Agmatine is transformed into N-carbamoylputrescine by agmatine imino hydroxylase (AIH). Finally, N-carbamoylputrescine is hydrolyzed to give putrescine. * In the second pathway, arginine is converted into

ornithine Ornithine is a non-proteinogenic amino acid that plays a role in the urea cycle. Ornithine is abnormally accumulated in the body in ornithine transcarbamylase deficiency. The radical is ornithyl. Role in urea cycle L-Ornithine is one of the produ ...

and then ornithine is converted into putrescine by

(ODC).

Occurrence

Putrescine is found in all

organism In biology, an organism () is any living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy into groups such as multicellular animals, plants, and ...

s. Putrescine is widely found in plant tissues, often being the most common polyamine present within the organism. Putrescine's role in development is well documented, but recent studies have suggested that putrescine also plays a role in stress responses in plants, both to biotic and abiotic stressors. The absence of putrescine in plants is associated with an increase in both parasite and fungal population in plants. Putrescine serves an important role in a multitude of ways, which include: a cation substitute, an osmolyte, or a transport protein. It also serves as an important regulator in a variety of surface proteins, both on the cell surface and on organelles, such as the mitochondria and chloroplasts. A recorded increase of ATP production has been found in mitochondria and ATP synthesis by chloroplasts with an increase in mitochondrial and chloroplastic Putrescine, but putrescine has also been shown to function as a developmental inhibitor in some plants, which can be seen as dwarfism and late flowering in ''Arabiadopsis'' plants. Putrescine production in plants can also be promoted by fungi in the soil. Piriformospora indica (''P. indica'') is one such fungus, found to promote putrescine production in '' Arabidopsis'' and common garden tomato plants. In a 2022 study it was shown that the presence of this fungus had a promotional effect on the growth of the root structure of plants. After gas chromatography testing, putrescine was found in higher amounts in these root structures. Plants that had been inoculated with ''P. indica'' had presented an excess of arginine decarboxylase. This is used in the process of making putrescine in plant cells. One of the downstream effects of putrescine in root cells is the production of auxin. That same study found that putrescine added as a fertilizer showed the same results as if it was inoculated with the fungus, which was also shown in ''Arabidopsis'' and

barley Barley (''Hordeum vulgare''), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains, particularly in Eurasia as early as 10,000 years ago. Globally 70% of barley p ...

. The evolutionary foundations of this connection and putrescine are still unclear. Putrescine is a component of

bad breath Bad breath, also known as halitosis, is a symptom in which a noticeably unpleasant breath odour is present. It can result in anxiety among those affected. It is also associated with depression and symptoms of obsessive compulsive disorder. Th ...

and bacterial vaginosis. It is also found in

semen Semen, also known as seminal fluid, is an organic bodily fluid created to contain spermatozoa. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphroditic animals and can fertilize the female ovum. Sem ...

and some microalgae, together with

and

Uses

Putrescine reacts with adipic acid to yield the polyamide nylon 46, which is marketed by DSM under the trade name Stanyl. Application of putrescine, along with other polyamines, can be used to extend the shelf life of fruits by delaying the ripening process. Pre-harvest application of putrescine has been shown to increase plant resistance to high temperatures and drought. Both of these effects seem to result from lowered ethylene production following exogenous putrescine exposure. Due to its role in putrification, putrescine has also been proposed as a biochemical marker for determining how long a corpse has been decomposing.

History

Putrescine and cadaverine were first described in 1885 by the

Berlin Berlin ( , ) is the capital and List of cities in Germany by population, largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's List of cities in the European Union by population within ci ...

physician Ludwig Brieger (1849–1919).

Toxicity

In rats, putrescine has a low acute oral toxicity of 2000 mg/kg body weight, with no-observed-adverse-effect level of 2000 ppm (180 mg/kg body weight/day).

References

External links

Putrescine MS Spectrum
{{Authority control Diamines Foul-smelling chemicals NMDA receptor antagonists 1,4-Butanediyl compounds