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: The addition of 1 mM adenosine to the myocardial cell cultures markedly increases the ATP concentration through a pathway reportedly leading to a compartmentalized ATP pool .
### Output Text:
The addition of 1 mM <span class="chemical">adenosine</span> to the myocardial cell cultures markedly increases the <span class="chemical">ATP</span> concentration through a pathway reportedly leading to a compartmentalized <span class="chemical">ATP</span> pool . 