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: RESULTS : Nontoxic doses of dexrazoxane reduced myelosuppression and weight loss from daunorubicin and etoposide in mice and antagonized their antiproliferative effects in the colony assay ; however , dexrazoxane neither reduced myelosuppression , weight loss , nor the in vitro cytotoxicity from doxorubicin .
### Output Text:
RESULTS : Nontoxic doses of <span class="chemical">dexrazoxane</span> reduced myelosuppression and weight loss from <span class="chemical">daunorubicin</span> and <span class="chemical">etoposide</span> in mice and antagonized their antiproliferative effects in the colony assay ; however , <span class="chemical">dexrazoxane</span> neither reduced myelosuppression , weight loss , nor the in vitro cytotoxicity from <span class="chemical">doxorubicin</span> . 