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: To further our understanding of the mechanism of CS cytoprotection , we examined in rats and mice the protective abilities of CS and the non - hydrolyzable ether form of CS , gamma - cholesteryloxybutyric acid , tris salt ( CSE ) against acetaminophen - , adriamycin - , carbon tetrachloride - , chloroform - and galactosamine - induced toxicity .
### Output Text:
To further our understanding of the mechanism of <span class="chemical">CS</span> cytoprotection , we examined in rats and mice the protective abilities of <span class="chemical">CS</span> and the non - hydrolyzable ether form of <span class="chemical">CS</span> , <span class="chemical">gamma - cholesteryloxybutyric acid</span> , <span class="chemical">tris salt</span> ( <span class="chemical">CSE</span> ) against <span class="chemical">acetaminophen</span> - , <span class="chemical">adriamycin</span> - , <span class="chemical">carbon tetrachloride</span> - , <span class="chemical">chloroform</span> - and <span class="chemical">galactosamine</span> - induced toxicity . 