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: The ACC - 9653 and phenytoin sodium treatments produced similar marked reductions in diastolic blood pressure and contractile force ( LVdP / dt ) .
### Output Text:
The <span class="chemical">ACC - 9653</span> and <span class="chemical">phenytoin sodium</span> treatments produced similar marked reductions in diastolic blood pressure and contractile force ( LVdP / dt ) . 