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: These data indicate that the free ED50 in plasma for terfenadine ( 1 . 9 nM ) , terodiline ( 76 nM ) , cisapride ( 11 nM ) and E4031 ( 1 . 9 nM ) closely correlate with the free concentration in man causing QT effects .
### Output Text:
These data indicate that the free ED50 in plasma for <span class="chemical">terfenadine</span> ( 1 . 9 nM ) , <span class="chemical">terodiline</span> ( 76 nM ) , <span class="chemical">cisapride</span> ( 11 nM ) and <span class="chemical">E4031</span> ( 1 . 9 nM ) closely correlate with the free concentration in man causing QT effects . 