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: We tested the sulfated polysaccharide fucoidan , which has been reported to reduce inflammatory brain damage , in a rat model of intracerebral hemorrhage induced by injection of bacterial collagenase into the caudate nucleus .
### Output Text:
We tested the sulfated polysaccharide <span class="chemical">fucoidan</span> , which has been reported to reduce inflammatory brain damage , in a rat model of intracerebral hemorrhage induced by injection of bacterial collagenase into the caudate nucleus . 