Skeletal formula of <a href="https://en.wikipedia.org/wiki/DMPX" class="extiw" title="w:DMPX">DMPX</a> (3,7-dimethyl-1-propargylxanthine). Created with <a rel="nofollow" class="external text" href="http://www.chemdoodle.com">ChemDoodle</a> and <a rel="nofollow" class="external text" href="http://www.adobe.com/products/illustrator.html">Adobe Illustrator CC 2017</a>.
<a href="//commons.wikimedia.org/wiki/User:Vaccinationist" title="User:Vaccinationist">Vaccinationist</a>
<span class="int-own-work" lang="en">Own work</span>, based on <a rel="nofollow" class="external text" href="https://pubchem.ncbi.nlm.nih.gov/compound/99562">PubChem</a>