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: Effect of converting enzyme inhibition on the course of adriamycin - induced nephropathy .
### Output Text:
Effect of converting enzyme inhibition on the course of <span class="chemical">adriamycin</span> - induced nephropathy . 