Biosynthese von Niacin (schematisch)
<a href="//commons.wikimedia.org/w/index.php?title=User:Van_Flamm&amp;action=edit&amp;redlink=1" class="new" title="User:Van Flamm (page does not exist)">Van Flamm</a>; vectorised with BKchem; <span class="int-own-work" lang="en">Own work</span>
<a href="//commons.wikimedia.org/wiki/File:Nicotinic_acid_biosynthesis2.png" title="File:Nicotinic acid biosynthesis2.png">File:Nicotinic acid biosynthesis2.png</a>