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: The protective effect of LY274614 was dose - dependent , being maximum at 10 - 40 mgkg ( i . p . ) .
### Output Text:
The protective effect of <span class="chemical">LY274614</span> was dose - dependent , being maximum at 10 - 40 mgkg ( i . p . ) . 