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: Maltolyl p - coumarate was found to attenuate cognitive deficits in both rat models using passive avoidance test and to reduce apoptotic cell death observed in the hippocampus of the amyloid beta peptide ( 1 - 42 ) - infused rats .
### Output Text:
<span class="chemical">Maltolyl p - coumarate</span> was found to attenuate cognitive deficits in both rat models using passive avoidance test and to reduce apoptotic cell death observed in the hippocampus of the <span class="chemical">amyloid beta peptide ( 1 - 42 )</span> - infused rats . 