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: Administration of salvianolic acid A for a period of 8 days significantly attenuated isoproterenol - induced cardiac dysfunction and myocardial injury and improved mitochondrial respiratory function .
### Output Text:
Administration of <span class="chemical">salvianolic acid A</span> for a period of 8 days significantly attenuated <span class="chemical">isoproterenol</span> - induced cardiac dysfunction and myocardial injury and improved mitochondrial respiratory function . 