-formyltetrahydromethanopterin</span></div><div class="line"><a name="l00283"></a><span class="lineno">  283</span>&#160;                                              <span class="stringliteral">&#39;CE&#39;</span>,  <span class="comment"># cerium (iii) ion</span></div><div class="line"><a name="l00284"></a><span class="lineno">  284</span>&#160;                                              <span class="stringliteral">&#39;NH3&#39;</span>,  <span class="comment"># ammonia</span></div><div class="line"><a na