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 date , only three cases of seizures associated with amphotericin B have been reported in the literature , but healthcare providers should be aware of the potential for this rare adverse effect .
### Output Text:
To date , only three cases of seizures associated with <span class="chemical">amphotericin B</span> have been reported in the literature , but healthcare providers should be aware of the potential for this rare adverse effect . 