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: Renal plasma flow increased , but albumin excretion and glomerulosclerosis did not change after enalapril treatment .
### Output Text:
Renal plasma flow increased , but albumin excretion and glomerulosclerosis did not change after <span class="chemical">enalapril</span> treatment . 