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: MK - 801 augments pilocarpine - induced electrographic seizure but protects against brain damage in rats .
### Output Text:
<span class="chemical">MK - 801</span> augments <span class="chemical">pilocarpine</span> - induced electrographic seizure but protects against brain damage in rats . 