span>,  <span class="comment"># 2-butanol</span></div><div class="line"><a name="l00217"></a><span class="lineno">  217</span>&#160;                                              <span class="stringliteral">&#39;PLP&#39;</span>,  <span class="comment"># pyridoxal-5&#39;-phosphate</span></div><div class="line"><a name="l00218"></a><span class="lineno">  218</span>&#160;                                              <span class="stringliteral">&#39;SR&#39;</span>,  <span class="comment"># strontium ion</span></