putrescin

Putrescin, commonly known as putrescine, is a diamine with the chemical formula H2N-(CH2)4-NH2. It is the smallest aliphatic polyamine and is typically present as a dication at physiological pH. Putrescine occurs in virtually all living cells and serves as a central intermediate in the polyamine biosynthesis pathway, acting as a precursor to spermidine and spermine, compounds that participate in stabilizing nucleic acids and regulating cellular processes.

In biosynthesis, putrescine is produced primarily from ornithine by the enzyme ornithine decarboxylase in eukaryotes; in bacteria and plants, it can also be formed from agmatine, itself derived from arginine, via agmatinase or related pathways. The aminopropyl groups donated by decarboxylated S-adenosylmethionine convert putrescine into spermidine and then spermine.

Occurrence and role: Putrescine is found in all tissues and is present in foods, where it can accumulate during fermentation or spoilage by microorganisms. In decaying tissues, putrescine contributes to characteristic odors and is produced by bacterial decarboxylation of amino acids.

Clinical and research context: Polyamines, including putrescine, are essential for normal cell growth and differentiation. Abnormally high levels of putrescine or other polyamines can be associated with certain diseases, including cancer and bacterial infections, and measurement of polyamines is used in some research and diagnostic contexts.

Safety: Putrescine is not highly toxic but is a basic amine; handling requires standard laboratory precautions to prevent irritation, and elevated exposure should be avoided.

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