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: METHODS : Renal ACE activity ( Hip - His - Leu cleavage by cortical homogenates ) was determined by renal biopsy in 27 adult male Wistar rats .
### Output Text:
METHODS : Renal ACE activity ( <span class="chemical">Hip - His - Leu</span> cleavage by cortical homogenates ) was determined by renal biopsy in 27 adult male Wistar rats . 