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: We measured the plasma level of brain natriuretic peptide ( BNP ) to determine whether BNP might serve as a simple diagnostic indicator of anthracycline - induced cardiotoxicity in patients with acute leukemia treated with a daunorubicin ( DNR ) - containing regimen .
### Output Text:
We measured the plasma level of brain natriuretic peptide ( BNP ) to determine whether BNP might serve as a simple diagnostic indicator of <span class="chemical">anthracycline</span> - induced cardiotoxicity in patients with acute leukemia treated with a <span class="chemical">daunorubicin</span> ( <span class="chemical">DNR</span> ) - containing regimen . 