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: Epileptogenic activity of folic acid after drug induces SLE ( folic acid and epilepsy )
### Output Text:
Epileptogenic activity of <span class="chemical">folic acid</span> after drug induces SLE ( <span class="chemical">folic acid</span> and epilepsy ) 