2D structure of <a href="https://en.wikipedia.org/wiki/betaxolol" class="extiw" title="w:betaxolol">betaxolol</a>, a β<sub>1</sub>-blocker.
<a href="//commons.wikimedia.org/wiki/User:Vaccinationist" title="User:Vaccinationist">Vaccinationist</a>
<span class="int-own-work" lang="en">Own work</span>