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 data indicate that phenylephrine - induced hypertension instituted 2 h after MCAO does not aggravate edema in the ischemic core , that it improves edema in the periphery of the ischemic territory , and that it reduces the area of histochemical neuronal dysfunction .
### Output Text:
The data indicate that <span class="chemical">phenylephrine</span> - induced hypertension instituted 2 h after MCAO does not aggravate edema in the ischemic core , that it improves edema in the periphery of the ischemic territory , and that it reduces the area of histochemical neuronal dysfunction . 