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: Elevations in the serum GOT and GPT were maximum in the sedentary - isoproterenols and minimum in the exercise - controls .
### Output Text:
Elevations in the serum GOT and GPT were maximum in the sedentary - <span class="chemical">isoproterenols</span> and minimum in the exercise - controls . 