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: CONCLUSIONS : Although neutropenia is not a common side effect of quetiapine , physicians should be cautious about its presentation and associated risk factors .
### Output Text:
CONCLUSIONS : Although neutropenia is not a common side effect of <span class="chemical">quetiapine</span> , physicians should be cautious about its presentation and associated risk factors . 