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 contents of albumin in the lungs were not changed , indicating that Captopril did not influence the extravasation of protein .
### Output Text:
The contents of albumin in the lungs were not changed , indicating that <span class="chemical">Captopril</span> did not influence the extravasation of protein . 