<p>Condensed structures (A,B, and C) of the compounds series described in Tables <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0161952#pone.0161952.t001" target="_blank">1</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0161952#pone.0161952.t002" target="_blank">2</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0161952#pone.0161952.t003" target="_blank">3</a>. (D) Structure of P<sub>2</sub> substituent of compound <b>18</b>.</p
