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: Bromocriptine was definitely effective in cases with prolactin greater than 35 ng . / ml .
### Output Text:
<span class="chemical">Bromocriptine</span> was definitely effective in cases with prolactin greater than 35 ng . / ml . 