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: Protective effect of clentiazem against epinephrine - induced cardiac injury in rats .
### Output Text:
Protective effect of <span class="chemical">clentiazem</span> against <span class="chemical">epinephrine</span> - induced cardiac injury in rats . 