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: In comparison to control , E and ED1 - ED4 showed highly significant analgesic and antiinflammatory activities ( p < 0 . 001 ) .
### Output Text:
In comparison to control , <span class="chemical">E</span> and ED1 - ED4 showed highly significant analgesic and antiinflammatory activities ( p < 0 . 001 ) . 