Definition of spermidine in US English:



  • A colorless compound with a similar distribution and effect to spermine.

    A polyamine; chemical formula: H₂N(CH₂)₃NH(CH₂)₄NH₂

    • ‘These specificities lead to preferential bindings through the DNA minor groove for putrescine and spermidine, whereas spermine binds by the major groove.’
    • ‘The effect was dose-dependent in the case of spermidine, but not putrescine and spermine.’
    • ‘The present study indicates that DNA resolubilization at high concentrations of spermine and spermidine is explained by formation of small particles of condensed DNA that cannot be precipitated by centrifugation.’
    • ‘This may be related to the role of arginine as a biochemical precursor in the synthesis of putrescine, spermidine, and spermine, which are believed to be essential to sperm motility.’
    • ‘Maybe even higher efficiencies would have been obtained using spermine instead of spermidine.’


1920s: from sperm + -ide + -ine.