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: Dysregulated diurnal cortisol may be indicative of inappropriate anticipation of forthcoming demands and hypersecretion may lead to the increased psychological and physical morbidity associated with heavy recreational use of ecstasy .
### Output Text:
Dysregulated diurnal <span class="chemical">cortisol</span> may be indicative of inappropriate anticipation of forthcoming demands and hypersecretion may lead to the increased psychological and physical morbidity associated with heavy recreational use of <span class="chemical">ecstasy</span> . 