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: Two patients treated with parenteral paramethasone ( Triniol ) and dexamethasone ( Sedionbel ) are described .
### Output Text:
Two patients treated with parenteral <span class="chemical">paramethasone</span> ( Triniol ) and <span class="chemical">dexamethasone</span> ( Sedionbel ) are described . 