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: Large doses of the cholinomimetic , pilocarpine , could induce catalepsy when peripheral cholinergic receptors were blocked .
### Output Text:
Large doses of the cholinomimetic , <span class="chemical">pilocarpine</span> , could induce catalepsy when peripheral cholinergic receptors were blocked . 