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: Estrogen binding sites were demonstrated by autoradiography in one transplantable and five primary diethylstilbesterol induced renal carcinomas in three hamsters .
### Output Text:
<span class="chemical">Estrogen</span> binding sites were demonstrated by autoradiography in one transplantable and five primary <span class="chemical">diethylstilbesterol</span> induced renal carcinomas in three hamsters . 