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: These results provide important new mechanistic information regarding the hepatotoxic effects of amiodarone and indicate that PPARalpha protects against amiodarone - induced hepatotoxicity .
### Output Text:
These results provide important new mechanistic information regarding the hepatotoxic effects of <span class="chemical">amiodarone</span> and indicate that PPARalpha protects against <span class="chemical">amiodarone</span> - induced hepatotoxicity . 