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: Taking these in vitro and in vivo results together , our study suggests that maltolyl p - coumarate is a potentially effective candidate against Alzheimer ' s disease that is characterized by wide spread neuronal death and progressive decline of cognitive function .
### Output Text:
Taking these in vitro and in vivo results together , our study suggests that <span class="chemical">maltolyl p - coumarate</span> is a potentially effective candidate against Alzheimer ' s disease that is characterized by wide spread neuronal death and progressive decline of cognitive function . 