Spermidine

**Definition:** A polyamine formed from putrescine. It is found in almost all tissues in association with nucleic acids. It is found as a cation at all pH values, and is thought to help stabilize some membranes and nucleic acid structures. It is a precursor of spermine.

**Tree numbers:** - D02.092.211.415.701.801 - D02.092.782.677