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: Scopolamine and pentobarbital blocked the pilocarpine - induced electrographic seizure , MK - 801 treatment augmented the electrographic seizure induced by pilocarpine .
### Output Text:
<span class="chemical">Scopolamine</span> and <span class="chemical">pentobarbital</span> blocked the <span class="chemical">pilocarpine</span> - induced electrographic seizure , <span class="chemical">MK - 801</span> treatment augmented the electrographic seizure induced by <span class="chemical">pilocarpine</span> . 