Chemical structure of <a href="https://en.wikipedia.org/wiki/Putrescine" class="extiw" title="en:Putrescine">diaminobutane</a>.
<b>Original: </b> <a href="//commons.wikimedia.org/wiki/User:RicHard-59" title="User:RicHard-59">RicHard-59</a>, <b>New version: </b> <a href="//commons.wikimedia.org/wiki/User:Alhadis" title="User:Alhadis">Alhadis</a>
2011-03-28 20:36
Own work based on: <a href="//commons.wikimedia.org/wiki/File:Diaminobutane.png" title="File:Diaminobutane.png">Diaminobutane.png</a> <i>by</i> <a href="//commons.wikimedia.org/wiki/User:Edgar181" title="User:Edgar181">Edgar181</a>