In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: We evaluated the potential of the major metabolite of cocaine , benzoylecgonine ( BE ) , to cause seizures .
### Output Text:
We evaluated the potential of the major metabolite of <span class="chemical">cocaine</span> , <span class="chemical">benzoylecgonine</span> ( <span class="chemical">BE</span> ) , to cause seizures . 