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: In order to investigate the effects of daidzein from Pueraria thunbergiana on scopolamine - induced impairments of learning and memory , we conducted a series of in vivo tests .
### Output Text:
In order to investigate the effects of <span class="chemical">daidzein</span> from Pueraria thunbergiana on <span class="chemical">scopolamine</span> - induced impairments of learning and memory , we conducted a series of in vivo tests . 