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: Sulpiride is a selective D2 - receptor antagonist with antipsychotic and antidepressant properties .
### Output Text:
<span class="chemical">Sulpiride</span> is a selective D2 - receptor antagonist with antipsychotic and <span class="chemical">antidepressant</span> properties . 