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: A novel compound , maltolyl p - coumarate , attenuates cognitive deficits and shows neuroprotective effects in vitro and in vivo dementia models .
### Output Text:
A novel compound , <span class="chemical">maltolyl p - coumarate</span> , attenuates cognitive deficits and shows neuroprotective effects in vitro and in vivo dementia models . 