Structural interactions of polyamines

Abstract

Polyamines are ubiquitous biological cations. We have determined the X-ray crystal Structures of a number of polyamine salts and complexes of diamines with acidic amino acids in order to obtain structural information on polyamine interactions. The conformations of diamines in the complexes  display variations reflecting the flexibliity in their backbone geometries. In all the structures, the amino group protons are involved in hydrogen bonds without large torsional strain on thc terminal C-N bond. Evaluation of the relative size of electrostatic, ran der Waals and hydrogen-bonding interactions suggests that all the term might be of significance in the formation of polyamine complexes.