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: A prerenal component could have contributed to renal failure because of a transient hypotension , due to an increasing ascitis , occurring just before anuria .
### Output Text:
A prerenal component could have contributed to renal failure because of a transient hypotension , due to an increasing ascitis , occurring just before anuria . 