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: Injection of Captopril ( 1 mg / kg ) , an inhibitor of angiotensin converting enzyme ( ACE ) , reduced both pulmonary and renal insufficiency in this rat model .
### Output Text:
Injection of <span class="chemical">Captopril</span> ( 1 mg / kg ) , an inhibitor of <span class="chemical">angiotensin</span> converting enzyme ( ACE ) , reduced both pulmonary and renal insufficiency in this rat model . 