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: FLA - 63 , a dopamine - beta - oxidase inhibitor , did not have any effect on the hypotension , bradycardia or reflex - enhancing effect of L - dopa .
### Output Text:
<span class="chemical">FLA - 63</span> , a <span class="chemical">dopamine</span> - beta - oxidase inhibitor , did not have any effect on the hypotension , bradycardia or reflex - enhancing effect of <span class="chemical">L - dopa</span> . 