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: Ethinyl estradiol treatment did not impair conjugation of deoxycholic acid , but did result in an increase in sulfation of taurodeoxycholic acid from 1 . 5 % in controls to nearly 4 . 0 % ( P less than 0 . 01 ) .
### Output Text:
<span class="chemical">Ethinyl estradiol</span> treatment did not impair conjugation of <span class="chemical">deoxycholic acid</span> , but did result in an increase in sulfation of <span class="chemical">taurodeoxycholic acid</span> from 1 . 5 % in controls to nearly 4 . 0 % ( P less than 0 . 01 ) . 